Knowable Magazine is from Annual Reviews, a nonprofit publisher dedicated to synthesizing and integrating knowledge for the progress of science and the benefit of society.

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The world has never seen anything like the race for Covid-19 vaccines. The breadth and speed of the effort is astonishing, with more than 160 projects underway, by World Health Organization counts. “All the strategies that have ever been used to make a vaccine, as well as several new strategies, are being used to make this one,” says Paul Offit, a pediatrician and vaccine developer at the Children’s Hospital of Philadelphia.

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Vaccine development usually takes more than a decade, but in this case the first large clinical trials have already begun or are being launched. If these phase 3 trials, as they’re termed, provide enough evidence of effectiveness, emergency regulatory approvals could soon follow.

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But vaccine development is famously tough. Despite the unprecedented speed, preliminary results from the earliest trials are only starting to trickle in, says microbiologist and infectious disease specialist Maria Elena Bottazzi of Baylor College of Medicine, who is a co-lead developer of a Covid-19 vaccine and coauthor of an article about vaccines for developing countries in the Annual Review of Medicine.

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And though the SARS-CoV-2 virus causing the pandemic is being intensively studied in thousands of labs, it retains many mysteries that may affect vaccine safety and effectiveness.

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How are Covid-19 vaccines being developed, tested and readied for approval? How will their safety and effectiveness be assessed — in a time when many people view vaccines with suspicion? Here’s a quick guide.

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How does developing vaccines for Covid-19 differ from normal drug development?

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Speed. These are all-out efforts to develop the vaccines in record time, while still following all the steps necessary to assure their safety.

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Each vaccine developer essentially has put its eggs into one or two baskets rather than having 20 varieties to test in the lab or in animals, says Manish Sadarangani, head of the Vaccines Evaluation Centre at BC Children’s Hospital in Vancouver, Canada, which pursues many forms of Covid-19 research.

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Regulators also have sped up the administrative process, prioritizing Covid-19 vaccines and reducing paperwork without compromising safety, Sadarangani says. And they’ve allowed some shortcuts to hasten clinical studies. For instance, the company Moderna Therapeutics, whose Covid-19 vaccine candidate (co-developed with the National Institute of Allergy and Infectious Diseases) was the first to run an early (phase 1) safety trial in the United States, was permitted to run the trial in parallel with full animal testing.

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Recruiting volunteers for these trials hasn’t been a problem: People are keen to participate, Sadarangani says. Professionals working on the trials, such as statisticians analyzing data and physicians on independent safety monitoring committees, give them top priority. “People are willing to work around the clock,” Sadarangani says.

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\"Photograph — \n
A volunteer in Binghamton, New York, receives an injection of a Covid-19 candidate vaccine in a newly launched phase 3 clinical trial. Developed by Moderna, Inc. and the National Institutes of Health, it is one of several vaccines now in large-scale testing.
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CREDIT: AP PHOTO / HANS PENNINK
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What does the safety record look like for other vaccines that have been developed?

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Good. “Vaccine developers are probably more concerned with safety than any other aspect of vaccine performance,” says Terence Dermody, a pediatrician and virologist at the University of Pittsburgh. “Because, quite frankly, if the vaccine is not safe, it doesn’t matter if it induces an immune response and it protects you.” Vaccines are given broadly and to people who are healthy, so even a small risk is unacceptable.

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Vaccines for diseases ranging from flu to measles to pneumococcal infections have a solid record of safety. While some people worry about the risk of anaphylactic shock (a life-threatening immune reaction), that’s about a one-in-a-million chance with most vaccines, Sadarangani says.

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The two polio vaccines, Salk and Sabin, offer another example of issues involving safety, Dermody adds. Both vaccines are extremely effective, but they differ: The Salk consists of fully destroyed virus while the Sabin is live virus that has been rendered harmless — attenuated. But there is a one-in-a-million (or lower) chance that the attenuated virus will mutate and flip back to a disease-causing state, causing polio cases. For that reason, the Sabin vaccine is not used in the US.

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One vaccine that’s often cited as a counterexample is a dengue vaccine that killed several young Filipino children. But the dengue outcome was unusual, driven by a phenomenon known as antibody-dependent enhancement, in which antibodies triggered by exposure to a pathogen or vaccine actually help the pathogen get into cells. Dengue comes in several strains and the vaccine does not protect equally against all of them; the deaths occurred in children who had not been exposed to dengue before, and later encountered a strain that the vaccine didn’t protect against.

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For this reason, the vaccine never got a thumbs-up for such children from the US Food and Drug Administration, and the WHO now recommends it only for individuals who have had dengue in the past.

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What makes SARS-CoV-2 a particular challenge for vaccine researchers?

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“It’s an unusual virus that we’re still learning about,” Offit says. Scientists don’t really know how the human immune system beats it back. Among the puzzles: Some people who develop symptoms don’t seem to generate much of an immune response, while others may kick off life-threatening immune overreactions called cytokine storms. Such overreactions have been seen in other diseases, including two caused by coronaviruses related to the one behind Covid-19: severe acute respiratory syndrome (SARS), which broke out in 2003, and Middle East respiratory syndrome (MERS), first reported in 2012.

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There are worries, in fact, that Covid-19 vaccines themselves may ignite immune over-responses. “That’s really an open question right now,” says Stanley Perlman, a virologist at the University of Iowa and a coauthor of an article about the MERS virus in the Annual Review of Medicine.

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No vaccines were ever approved for SARS or MERS, though vaccine candidates entered early clinical studies: Both diseases were stamped out mostly by testing and isolating infected people. But several of the Covid-19 candidates have built on the SARS and MERS vaccine work, offering important clues on effectiveness and safety. Both immune overreactions and antibody-dependent enhancement cropped up in animal studies of SARS vaccine candidates, and developers are on the lookout for both risks as they design and test their candidates.

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Will the manufacturing method influence the likelihood of agencies granting emergency approval for Covid-19 vaccines?

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Clinical trials will be used to provide evidence of safety and effectiveness, regardless of the precise technique by which a vaccine is made.

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Developers are taking a wide range of approaches and they don’t know which one is most likely to work. For instance, among the candidates now in phase 3 trials, vaccines from China’s Sinopharm and a collaboration between the University of Oxford and the company AstraZeneca use a non-replicating virus — a harmless virus particle that can’t reproduce but carries genetic material encoding the SARS-CoV-2 spike protein. The Chinese biotech company Sinovac uses inactivated — killed — Covid-19 virus.

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The Moderna vaccine is based on messenger RNA molecules that contain instructions for making SARS-CoV-2 proteins. Once the mRNA is injected, the recipient’s own cells generate the vaccine proteins. This is a new approach that has shown promise in small, early clinical trials for SARS-CoV-2 vaccines and ones against other viruses, but no mRNA-based vaccine has yet been approved for any infectious disease.

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These varied approaches raise different challenges in designing, manufacturing and delivering a vaccine, but regulatory agencies will monitor each step for safety and effectiveness.

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How are the phase 3 clinical studies designed?

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The WHO, the FDA and other regulatory bodies are setting up common guidelines for these crucial big trials so that vaccines can be judged systematically.

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Typically, the main measurement for approval is prevention of Covid-19 disease with detectable symptoms. The trials all need to run until tests show that a certain number of participants have been exposed to the virus in their normal lives. (So far, no trials have been approved that directly expose healthy participants to the Covid-19 virus, although such human challenge trials have been discussed.)

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Thousands of people need to be enrolled to see results. For example, among the first phase 3 studies — all of which followed earlier, smaller studies — a trial of Moderna’s vaccine candidate will enroll about 30,000 healthy people in the US and give half of them the vaccine candidate. The other half — randomly selected — will get a placebo. And the University of Oxford/AstraZeneca collaboration plans to test its vaccine in roughly 50,000 people in the United Kingdom and several other countries.

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\"A — \n
By the time you look at this, it may be out of date — that’s how fast Covid-19 vaccine research is moving. Above are candidate vaccines that, as of July 30, have passed through safety trials and entered large clinical trials in which tens of thousands of volunteers will receive — on a random basis — the experimental vaccine or a sham. Then it’s a matter of tracking to see if the vaccine group is better protected against Covid-19 circulating in the community than the control group. Safety monitoring is a key part of such trials. A broad array of vaccine approaches is being looked at — in the six above, three vaccines use killed (inactivated) virus particles. One vaccine uses a harmless virus that causes colds in non-human primates; it cannot replicate in human cells and has been modified so that it directs the manufacture of the spike protein that sits on the surface of the SARS-CoV-2 virus. Two use messenger RNA that carries instructions for a version of the SARS-CoV-2 spike protein. The RNA is encased in an oily lipid envelope to help it enter cells; once inside, the cell’s protein-making machinery creates the spike protein, which can’t cause disease but enables the immune system to be primed for a later encounter with the SARS-CoV-2 virus itself.
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What will these studies tell us about the vaccine’s safety?

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The trials will be large enough to pick up short-term and common safety problems, Dermody says. “If one in 30 people develop high-grade fever or a seizure, you’ll see that.”

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Side effects that take longer to develop or are very rare — affecting, say, one in 10,000 or 100,000 people — will be harder to spot, Dermody adds. But “I have confidence that even with the warp speed magnitude of this work, these study subjects will be observed very carefully,” he says.

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Additionally, the United States and most other high-income countries have systems in place to pick up very rare but potentially serious adverse events from vaccines after they have been approved and are given to vast numbers of people beyond clinical trials.

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What side effects will be seen as acceptable in a vaccine proposed for wide adoption?

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Some side effects are not acceptable in terms of medical harm — even fainting, as experienced by a healthy 29-year-old volunteer who was given the highest test dose of the Moderna vaccine. That dose was dropped from further testing.

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Others are more benign. “People may get sore arms and swelling and fever, and some of these vaccines may cause more of those side effects than some of the vaccines we use routinely,” Sadarangani says. A vaccine under development by CanSino Biologics, for example, produced fever in almost half of its recipients in an early trial.

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But in a pandemic, these reactions might be acceptable to many, particularly if someone is in a high-risk group. And they might be similar to those for a number of existing vaccines. For example, about one in six people given the Shingrex shingles vaccine have side effects such as headache or muscle pain that interfere with normal activities for a few days, according to the Centers for Disease Control and Prevention.

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How effective must vaccines be?

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“Vaccine developers are probably more concerned with safety than any other aspect of vaccine performance ….If the vaccine is not safe, it doesn't matter if it induces an immune response and it protects you.”

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Both the WHO and the FDA say they will require at least 50 percent effectiveness for a full Covid-19 vaccine approval, and the WHO lists at least 70 percent effectiveness as a preferred goal. (For comparison, two doses of the measles/mumps/rubella vaccine offer about 97 percent protection to children, while the effectiveness of last season’s annual flu vaccines was about 45 percent in the US.) Though neither agency has a detailed definition of “effectiveness,” the ability to prevent severe disease is key. The FDA and other regulatory agencies also can authorize emergency use for vaccines that don’t meet these standards, on a case-by-case basis.

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How much control over the pandemic we would get from this level of effectiveness also depends, of course, on how widely vaccines are adopted. There are no magic numbers, says Michael Osterholm, an infectious disease expert at the University of Minnesota at Minneapolis. “Anything we get will be helpful.”

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If a vaccine is effective, will it prevent recipients from transmitting Covid-19?

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Not necessarily. The FDA may consider a vaccine effective if recipients end up with a mild case of the disease or carry the virus without getting sick at all. In such a case, Perlman says, there is a possibility we might be protected ourselves but potentially still shed the virus to people who haven’t been vaccinated, although maybe dramatically less than an infected person would.

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How long will the trials run?

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Solid answers might come as quickly as three to five months after full enrollment in a phase 3 trial, the WHO says. Experts cautiously concur, but setting exact deadlines for these trials isn’t possible. Since the trials require enough people who got the vaccine or placebo to be exposed to the virus in daily life, results may come sooner in spots where the pandemic is raging, and later in places where it’s less severe.

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Do experts worry that vaccines will be licensed prematurely?

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Yes. They see a risk that regulatory agencies will be pressured from above to give green lights to products before proper, careful trials have fully run their course. “Regulatory bodies know how to be very cautious at reviewing the data and allowing the stages to proceed, and there are a lot of other checks and balances in place,” Bottazzi says. “We know that the process works. I hope that they don’t feel that they need to jump over some of the process in the safety arena because they need something quick.”

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Offit and a coauthor warned of just such a dangerous scenario in the US in a June opinion article in the New York Times. “Obviously, when we have a thousand people dying a day, we want to get something out there as quickly as possible to save people’s lives,” he says now. “But we certainly should do this the way we’ve always done: with large placebo-controlled phase 3 trials. We can’t short-circuit that step, because that’s the proof.”

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When and if vaccines prove safe and effective, how will the public view them?

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Broad adoption will be a struggle in many countries, even if trials deliver solid clinical proof.

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A May 2020 survey in the United States, for example, found that only 49 percent of the 1,056 respondents said they planned to get a Covid-19 vaccine. (Other polls have reported higher numbers.) “If we start getting vaccines that don’t work and have side effects, that 49 percent, which is really horrible, will go even lower,” Perlman says. “On the other hand, if we have evidence that a vaccine is working, I think the 49 percent could creep up to the maximum, which is probably around 85 percent in the US. It’s really important that this be done right.”

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A minority of people are so opposed to vaccines they will never accept them as safe, but “most people trust vaccines,” Offit says. “We need to make sure that as we move forward with these vaccines, we manage expectations so that we don’t lose the confidence of the American public.”

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Readiness to take a vaccine presumably will grow as the Covid-19 toll keeps climbing. “I don’t think people have a good sense of just how much more pain, suffering, death and economic disruption still will occur,” Osterholm says. “It’s a crazy situation right now. We’ve just got to stay with the science.”

\n\n","field_all_authors":"

By Eric Bender 07.30.2020

\n\n","field_author_bios":"

Eric Bender is a science writer in a Massachusetts county where almost 2,000 people have died of Covid-19 so far.

\n\n","field_banner_alt":"Conceptual illustration featuring a syringe and virus particles.","field_banner_title":"Covid-19 vaccine","field_caption":"

Thousands of scientists across the world are working to develop safe and effective vaccines against Covid-19.

\n\n","field_credit":"

CREDIT: KNOWABLE MAGAZINE

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Explained

\n\n

Getting a Covid-19 vaccine — quickly and safely

\n\n

Researchers around the globe are working with unprecedented speed to find the vaccines we need to find our way through the pandemic. What’s the bar for safety and effectiveness?

\n\n

By Eric Bender

\n\n

7.30.2020

\n\n

\n\n\n\n

\n\n

And though the SARS-CoV-2 virus causing the pandemic is being intensively studied in thousands of labs, it retains many mysteries that may affect vaccine safety and effectiveness.

\n\n

How does developing vaccines for Covid-19 differ from normal drug development?

\n\n

Speed. These are all-out efforts to develop the vaccines in record time, while still following all the steps necessary to assure their safety.

\n\n

What does the safety record look like for other vaccines that have been developed?

\n\n

For this reason, the vaccine never got a thumbs-up for such children from the US Food and Drug Administration, and the WHO now recommends it only for individuals who have had dengue in the past.

\n\n

What makes SARS-CoV-2 a particular challenge for vaccine researchers?

\n\n

Will the manufacturing method influence the likelihood of agencies granting emergency approval for Covid-19 vaccines?

\n\n

Clinical trials will be used to provide evidence of safety and effectiveness, regardless of the precise technique by which a vaccine is made.

\n\n

These varied approaches raise different challenges in designing, manufacturing and delivering a vaccine, but regulatory agencies will monitor each step for safety and effectiveness.

\n\n

How are the phase 3 clinical studies designed?

\n\n

The WHO, the FDA and other regulatory bodies are setting up common guidelines for these crucial big trials so that vaccines can be judged systematically.

\n\n

What will these studies tell us about the vaccine’s safety?

\n\n

The trials will be large enough to pick up short-term and common safety problems, Dermody says. “If one in 30 people develop high-grade fever or a seizure, you’ll see that.”

\n\n

What side effects will be seen as acceptable in a vaccine proposed for wide adoption?

\n\n

How effective must vaccines be?

\n\n

If a vaccine is effective, will it prevent recipients from transmitting Covid-19?

\n\n

How long will the trials run?

\n\n

Do experts worry that vaccines will be licensed prematurely?

\n\n

When and if vaccines prove safe and effective, how will the public view them?

\n\n

Broad adoption will be a struggle in many countries, even if trials deliver solid clinical proof.

\n\n

10.1146/knowable-073020-1

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Eric Bender is a science writer in a Massachusetts county where almost 2,000 people have died of Covid-19 so far.

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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.

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$\"Knowable$

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By the time a person starts exhibiting the memory problems and other symptoms of Alzheimer’s disease, a catastrophic cascade of cellular events has been playing out inside their brain for years or even decades. Misfolded proteins and fragments of protein have been ever so slowly clumping together, forming microscopic plaques and tangles that interfere with the function of neurons. Eventually, these brain cells die and this neurodegeneration takes its toll on memory and cognition.

The slow-burning fuse of Alzheimer’s creates a terrible predicament for doctors, patients and the scientists working to develop therapies: Once symptoms appear, so much damage has already been done that it may be impossible to reverse. This might explain why clinical trials for experimental drugs intended to slow or reverse the cellular damage caused by Alzheimer’s disease have so far yielded one demoralizing failure after another. (Several drugs have been approved to treat the symptoms by boosting certain neurotransmitters, but none target the underlying cause of the disease.)

Many researchers now believe that those clinical trials may have failed because the experimental drugs were given too late in the course of the disease. Some of the same drugs — or new ones — might have a better chance if administered earlier, even before symptoms appear. It’s a hypothesis with logical appeal, but it’s still unproven. And it depends on the ability to detect signs of Alzheimer’s in people who aren’t yet experiencing symptoms.

In recent years, scientists have developed several methods for doing just that. The best-established biological markers are based on brain scans and tests of cerebrospinal fluid. More recently, researchers have finally made major breakthroughs in their decades-long pursuit of a simple blood test for Alzheimer’s-related proteins. These biomarker tests have clarified how the disease progresses, and they’re now widely used in Alzheimer's clinical trials. They’re not yet commonplace in clinical practice, but that’s likely to change in the next few years.

“There’s evidence that biomarkers start to show changes 20 years before onset of dementia,” says Andrew Saykin, director of the Alzheimer’s Disease Research Center at the Indiana University School of Medicine. That presents a huge window for early therapeutic intervention. Once effective therapies finally become available, many researchers think they’ll work best when given as early as possible. “It’s very tough to reverse neurodegeneration once it’s happened, but if we could prevent it from happening there’s really an opportunity to have a major impact on the disease,” Saykin says.

\"Table — A definitive diagnosis of Alzheimer’s disease traditionally was only possible after death. Emerging tests may soon allow physicians to better gauge risk and make confident diagnoses.
\n \n \n \n

Visualizing the problem

Alzheimer’s disease is the most common cause of dementia, affecting an estimated 5.8 million Americans. Memory problems are often the first sign, but confusion and other cognitive difficulties appear as the disease progresses, along with changes in mood, behavior and personality. To make a diagnosis, doctors typically interview the patient and a family member, and conduct cognitive assessments. They may also order brain scans or other tests to rule out a stroke or another type of dementia.

A definitive diagnosis, however, can come only after a person has died, by examining slices of brain tissue under a microscope. The pathological signature of Alzheimer’s has two components: plaques, which are clumps of a protein fragment called beta-amyloid that can be seen in the spaces between cells, and tangles, twisted strands of a protein called tau that form inside of cells. This combination of abnormalities is what distinguishes Alzheimer’s disease from other types of dementia that are also caused by abnormal deposits of proteins, including Lewy body dementia and fronto-temporal dementia. Scientists still don’t understand exactly how amyloid and tau cause neurodegeneration, but most believe these two compounds are key links in the disease mechanism. (An increasingly vocal minority of researchers, however, argues that more investigation of alternative mechanisms is needed.)

In 2002, Alzheimer’s researchers made a huge breakthrough with a method that made it possible to visualize amyloid buildup in the living human brain for the first time. Up to that point, more than a decade of pathology studies, mouse experiments and other research had implicated amyloid as a culprit in the disease, but there was no way to detect it in the brains of living people. The solution, developed by a team led by researchers at the University of Pittsburgh, was a compound that incorporates a radioactive isotope of carbon (C11) and binds to amyloid, making it visible on a positron emission tomography (PET) brain scan.

“Amyloid PET scanning was really just transformative,” says William Jagust, a neuroscientist the University of California, Berkeley. The new scans revolutionized clinical trials for Alzheimer’s disease, he and other experts say. Many leading candidate therapies are drugs or antibodies designed to clear amyloid from the brain, or at least stop it from building up. As researchers began using amyloid-targeted PET, they realized that a significant proportion of the patients enrolled in these trials didn’t actually have elevated amyloid in their brains, despite having memory impairments or other cognitive symptoms.

“About a third of the people who were enrolled in these clinical trials for ‘Alzheimer’s disease’ actually turned out not to have Alzheimer’s disease,” says Clifford Jack, a brain imaging researcher at the Mayo Clinic in Rochester, Minnesota. “That’s a really huge problem.”

Now virtually all clinical trials of anti-amyloid therapies use amyloid PET to screen patients for enrollment and to track whether the therapy being tested actually removes amyloid from the brain. Newer compounds based on a different radioactive isotope, Fluorine-18, have expanded their use in research even more. The original C11 compound has a half-life of about 20 minutes, which limits its use to hospitals with a cyclotron (a particle accelerator) and chemists on-site to manufacture their own supply, says Richard Carson, a PET imaging researcher at Yale University, and coauthor of a 2019 paper on the method in the Annual Review of Biomedical Engineering. “You have to be able to make the molecule very close to where you’re going to use it,” he says. In contrast, the new F18 compounds have about a two-hour half-life, which means they can be made in one place and shipped to hospitals that don’t have the capacity to make it themselves.

Amyloid PET has also made it possible to test experimental therapies in people who show signs of amyloid accumulation but aren’t yet experiencing memory problems. The largest such effort to date is called the A4 study, which has enrolled 1,169 people between the ages of 65 and 85 with abnormal amyloid PET scans but normal scores on cognitive tests (A4 stands for Anti-Amyloid Treatment in Asymptomatic Alzheimer’s). Participants were randomly assigned to receive either anti-amyloid therapy or a placebo, and researchers used cognitive tests and additional PET scans to track each person for four-and-a-half years.

The trial, which began enrolling patients in 2014, was nearing completion but has experienced delays due to the pandemic, says Reisa Sperling of Harvard Medical School, one of the study’s leaders. The trial will be an important test of the early-is-better treatment strategy. Sperling expects to have results by early 2023.

Biomarker diversity

In addition to changing clinical trials, amyloid PET and other biomarkers have changed the way researchers conceptualize Alzheimer’s, says neurologist Michael Weiner of the University of California, San Francisco, who leads the Alzheimer’s Disease Neuroimaging Initiative. The project, funded by more than $190 million from the federal government and the pharmaceutical industry since its launch in 2004, focuses on developing Alzheimer’s disease biomarkers. “We don’t think of the diagnosis being made by symptoms [anymore], we think of identifying pathology using biomarkers,” Weiner says. “It’s a huge shift in our thinking and our diagnostic and therapeutic approach.”

That shift is spelled out in detail in research recommendations published in 2018 by the National Institute on Aging and the nonprofit Alzheimer’s Association that urge researchers — though not yet clinicians — to define Alzheimer’s using biomarkers, much as clinicians already do for other conditions, such as using blood sugar tests to diagnose diabetes and bone density tests to diagnose osteoporosis. Doing so, the researchers argue, would enable researchers to design studies based on subjects with similar biology rather than focusing on cognitive symptoms, which can have differing biological underpinnings. “In that paper we basically say that someone has Alzheimer’s disease if they have positive amyloid and positive tau biomarkers,” says Jagust, who was one of the authors. A patient’s symptoms don’t factor into this definition.

The ability to visualize tau in the living human brain has become possible only in recent years, with the development of new compounds that make tau visible on a PET scan. The emerging research on tau PET scans suggests that they may match up better with a person’s cognitive status than amyloid PET scans do, Jagust says. “If you have a whole lot of tau in your brain, it’s very improbable that you’re going to be cognitively normal, whereas you can have a whole lot of amyloid in your brain and still be cognitively normal.”

That fits with the idea that tau accumulation occurs at a later stage of the disease than amyloid accumulation. Indeed, the overall picture emerging from Alzheimer’s biomarker research is that different biomarkers track different stages of the disease process, much as Jack and colleagues proposed in a widely cited paper more than a decade ago (see graphic below).

\"Graphic — Research suggests that different biomarkers correspond with different phases of Alzheimer’s disease. First amyloid begins to accumulate, then tau. Neurodegeneration causes memory loss and other symptoms as the disease progresses.
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The earliest indicator that trouble is brewing appears to be tests that detect amyloid fragments circulating in the cerebrospinal fluid (CSF) that bathes and cushions the brain and spinal cord. The type of amyloid implicated in Alzheimer’s disease is a fragment created when enzymes break down a much larger protein. What this protein and its fragments normally do in the brain, and why this particular fragment clumps together in the brains of Alzheimer’s patients, is poorly understood. Somewhat counterintuitively, researchers find that low levels of amyloid circulating in the CSF correlates with more amyloid building up in the brain.

“At this point, it looks like the CSF biomarkers become abnormal a little bit before the imaging biomarkers,” says Jack. That makes sense, he says, because the CSF tests probably indicate that something has gone wrong with amyloid production or turnover that’s causing it to build up in the brain. But it has to amass for a while — possibly years — before it can be seen with PET. “It takes a pretty substantial amount of amyloid to be deposited before you can actually detect it out of the noise with amyloid PET,” he says.

Tau appears to begin accumulating later, overlapping considerably with neurodegeneration and memory problems but preceding the severe cognitive decline that robs people of their independence in later stages of the disease. By that time, atrophy of certain brain regions can often be seen on MRI scans, which show brain anatomy in greater detail than PET does.

The distribution of tau in the brain differs from that of amyloid, says Jagust. “Amyloid seems to arise in multiple areas of the brain much at the same time, almost like it’s like blossoming everywhere,” he says. Tau, in contrast, appears to pile up first in the medial temporal lobe, a region critical for memory, and then spread to other areas, PET studies have shown. In a 2017 paper, Jagust and colleagues suggested that focusing on tau accumulation in specific brain regions instead of just detecting its presence or absence might provide a better indicator of neurodegeneration and cognitive symptoms.

\"A — Abnormal tangles of a protein called tau (yellow), seen here in brain tissue from an Alzheimer’s patient, are a hallmark of the disease — and one target of biomarker research.
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CREDIT: THOMAS DEERINCK, NCMIR / SCIENCE SOURCE
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While many researchers remain focused on refining biomarkers for amyloid and tau, others are investigating additional markers that could help push detection of the disease even earlier. These include genetic tests to assess an individual’s risk (see sidebar), tests for olfactory deficits or other sensory abnormalities that may predict Alzheimer’s disease, and digital diagnostics that use computers or other devices to assess cognition without a visit to the doctor’s office. Other approaches include investigating whether machine-learning algorithms can help neurologists pick up signs of trouble in brain scans, and new PET compounds that can detect the loss of synapses, the tiny gaps between neurons that are essential for communication from one cell to another.

Clinical practices

Even the more established biomarkers for Alzheimer’s disease aren’t yet widely used in clinical practice. Medicare, the government health insurance program that covers most older Americans, does not cover PET amyloid scans for most patients, and few opt to pay out of pocket for a test that costs several thousand dollars and likely wouldn’t change doctors’ treatment plan, given the absence of disease-altering drugs. Medicare makes exceptions, however, for certain cases in which a negative PET amyloid scan would aid diagnosis by ruling out Alzheimer’s disease, and for clinical research. (The FDA just approved the first tau PET test at the end of May.)

One recent study examined the medical records of 11,409 Medicare patients who had received an amyloid PET scan under one of these exemptions. The researchers, led by Gil Rabinovici at UCSF, reported last year in the Journal of the American Medical Association that amyloid PET scan results altered physicians’ treatment plans. Doctors were more likely to prescribe certain drugs for people with a positive PET scan, even if they hadn’t been diagnosed with Alzheimer’s disease. These drugs alter neurotransmitter function and have been shown to improve cognition in some people with Alzheimer’s disease, although they do not prevent neurodegeneration. Whether the patients benefitted in the long run is the focus of a follow-up study now underway.

\n $\"A$

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CREDIT: ZITA / SHUTTERSTOCK

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Calculating genetic risk

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Several genetic variations increase a person’s risk of developing Alzheimer’s disease in old age. The best-studied of these involves a gene called APOE. People who inherit the APOE ε4 version of this gene have two to four times the lifetime risk; people who inherit two copies (one from each parent) have eight to 12 times the risk. Even that higher risk doesn’t mean someone is destined to get Alzheimer’s, says Andrew Saykin, of the Indiana University School of Medicine. Factors such as age, gender, race, lifestyle and environment also play a role.

Many other genes influence risk, too, and researchers are developing risk scores that take these effects into consideration. “We might have a list of 20, 50 or 300 different genetic markers that all might have a small contribution above and beyond APOE,” Saykin says. It’s a promising area of research, he says, but such tests aren’t yet ready for clinical use. —Greg Miller

How patients themselves react to amyloid PET scan results was the focus of an even more recent study. Emily Largent and Jason Karlawish at the University of Pennsylvania and colleagues interviewed 80 cognitively unimpaired participants of the A4 study after their amyloid PET scan. Elevated amyloid, the researchers explained, means a higher but uncertain risk of eventually developing Alzheimer’s-related memory loss. Those who tested positive saw the result as “more serious and sensitive” than other types of medical test results, the researchers reported in February in the journal PLOS ONE. “A colonoscopy isn’t going to change who I am ... this is my brain involved,” one participant told the researchers. Many of those who tested positive also feared stigmatization or social isolation as a result and reported spending more time contemplating and planning for their future.

Karlawish says the findings underscore the need for doctors to help patients prepare for amyloid PET scans and discuss the results with them afterwards. “Before you order a test, particularly one that has consequences like this, you need to sit down and make sure the person understands what they’re walking into,” he says.

Clues in the blood

It’s a scenario that could soon become more common. One of the fastest-developing areas of Alzheimer’s biomarker research is on tests that can be done with an ordinary blood sample. It’s a goal that researchers have pursued for decades but begun to achieve only in the last few years.

One reason it’s been so difficult is that the blood-brain barrier, a cellular defense wall that protects the brain from any toxins circulating through the rest of the body, prevents potential biomarker molecules from getting into the bloodstream in significant amounts. Another reason is that, compared with CSF, blood contains many additional proteins that can foul up the analysis. “You have something like 50,000 times less signal to noise in the blood,” says Randall Bateman, a neurologist at Washington University in St. Louis. Bateman’s research group is one of several around the world that have recently begun to overcome these obstacles with new, super-sensitive assays that can detect minuscule amounts of amyloid or tau in blood samples.

One of the most promising methods involves a combination of techniques. The first is immunoprecipitation, which uses immune system proteins called antibodies to seek out a particular protein in a sample and concentrate it. The concentrated protein can then be fed into a mass spectrometer, a machine used by chemists to identify and quantify compounds by their molecular weight.

In 2017, Bateman and colleagues reported that a blood test based on this approach matched amyloid PET scan results in 41 adults age 60 or older. All study subjects who had positive PET scans had amyloid blood levels below a certain threshold, indicative of a higher risk of Alzheimer’s. However, several subjects with negative PET scans also had amyloid blood levels below this threshold, suggesting that improvements may be needed to avoid false positives.

Bateman’s group and others have been working to refine the tests. In 2018, researchers in Japan and Australia published details of a similar blood test that matched amyloid PET results with about 90 percent accuracy in a larger sample of 254 older adults. Preliminary findings reported earlier this year suggest that these blood tests have promise for predicting the onset of Alzheimer’s disease in people who don’t yet have symptoms or are experiencing only mild cognitive impairment.

Researchers have also made recent progress on a blood test for tau. In a paper published July 28 in the Journal of the American Medical Association, an international team of researchers reported that a blood test for a specific subtype of tau accurately distinguished Alzheimer’s disease from other neurodegenerative diseases in 1,402 study subjects from Colombia, Sweden and the United States. The blood test was as accurate as CSF tests and PET scans for tau. In one arm of the study, the blood test picked up signs of tau accumulation about 20 years before the onset of symptoms in people with a gene mutation that causes a rare, early-onset form of Alzheimer’s.

If blood tests for amyloid and tau prove to be reliable for diagnosing and predicting the course of Alzheimer’s disease, the impacts could be huge. Unlike PET scans, which are expensive and require injecting a radioactive tracer into the patient, and CSF tests, which involve inserting a needle into the spinal column, a blood test could be used far more widely. “By having a blood test, the numbers of people we can screen for Alzheimer’s and enroll in clinical trials grows by orders of magnitude,” says Bateman. It’s also much faster and cheaper than the alternatives, he says. “At the end of the day, what that really means is we are accelerating the time to find more effective treatments.”

A blood test could also help remove some of the uncertainty around the clinical diagnosis of Alzheimer’s disease in routine practice, Bateman says. Memory problems have many potential causes, so doctors can’t always confidently diagnose patients. Not knowing can be stressful for patients and their families, Bateman says. “It helps a lot when people know what they’re dealing with and what they can expect, and we come up with a plan for what to do about it.”

Some researchers see a day when doctors will use blood tests to gauge a patient’s risk of Alzheimer’s disease much as they now use blood tests for cholesterol to gauge the risk of heart disease — by plugging the test results into a formula that also considers their age, family history and other risk factors. “I can imagine that within five years from now, we will have that for Alzheimer’s disease,” says Sperling. “But I don’t think we have it yet.”

For the time being, Sperling sees no reason for people to seek out biomarker tests for Alzheimer’s disease unless their doctor has advised it. “Right now, I would tell people to do exactly the same things … whether they have a genetic risk factor or a clear biomarker or not,” says Sperling. That includes the usual advice to be physically active, stay mentally and socially engaged, and eat a heart-healthy diet. Biomarkers will make a real difference in helping patients, she says, only once effective therapies finally become available. “When we have a drug that alters amyloid or tau, everything will change.”

\n","field_all_authors":"

\n \n \n \n By\n\n \n Greg Miller\n \n \n \n \n 08.07.2020\n

\n","field_ar_article":{"arguments":[]},"field_author_bios":"

Greg Miller is a science journalist based in Portland, Oregon. Follow him on Twitter @dosmonos.

\n","field_banner_alt":"Illustration shows a physician analyzing MRI brain scans.","field_banner_title":"Biomarkers for Alzheimer’s","field_caption":"

A range of new methods look for signs of Alzheimer's disease years before symptoms appear. They’ve radically changed research and clinical trials — and may be key to developing effective treatments.

\n","field_credit":"

CREDIT: ROY SCOTT / SCIENCE SOURCE

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Seeking a better test for Alzheimer’s

New blood assays and brain scans are among the biomarkers revolutionizing clinical trials and changing the way researchers think of the disease. They may soon change the way patients are treated as well.

\n By Greg Miller \n \n

8.7.2020

Visualizing the problem

Biomarker diversity

Clinical practices

CREDIT: ZITA / SHUTTERSTOCK

Calculating genetic risk

Clues in the blood

10.1146/knowable-080720-1

\n\n

Greg Miller is a science journalist based in Portland, Oregon. Follow him on Twitter @dosmonos.

This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.

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The unusual cases of pneumonia began to appear in midwinter, in China. The cause, researchers would later learn, was a coronavirus new to science. By March, the infection began to spread to other Asian countries and overseas. People were dying, and the World Health Organization issued a global health alert.

But this was 2003, not 2020, and the disease was SARS, not Covid-19. By June, the outbreak was almost gone, with just 8,098 confirmed infections and 774 deaths worldwide. No cases of SARS have been reported since 2004.

Contrast that with the closely related coronavirus that causes Covid-19 today: more than 13,600,000 confirmed cases as of July 16, and more than 585,000 deaths.

Why did SARS go away while today’s coronavirus just keeps on spreading? Why, for that matter, did both these coronaviruses spill over into people at all, from their original bat hosts?

And just as vital as those questions is another: What happens next?

As we face the current pandemic, it will be important to understand how SARS-CoV-2, the virus that causes Covid-19, is likely to evolve in the months and years ahead. It’s possible the virus could lose its lethal character and settle into an evolutionary détente with humanity. It might end up as just another cold virus, as may have happened to another coronavirus in the past. But it could also remain a serious threat or perhaps even evolve to become more lethal. The outcome depends on the complex and sometimes subtle interplay of ecological and evolutionary forces that shape how viruses and their hosts respond to one another.

“One thing you learn about evolution is never to generalize,” says Edward Holmes, an evolutionary virologist at the University of Sydney, Australia, and author of an article on the evolution of emerging viruses in the Annual Review of Ecology, Evolution, and Systematics. “It depends entirely on the biological nuance of the situation.”

Steps to viral success

Many of the scariest viruses that have caused past or current epidemics originated in other animals and then jumped to people: HIV from other primates, influenza from birds and pigs, and Ebola probably from bats. So, too, for coronaviruses: The ones behind SARS (severe acute respiratory syndrome), MERS (Middle East respiratory syndrome) and Covid-19 all probably originated in bats and arrived in people via another, stepping-stone species, likely palm civets, camels and possibly pangolins, respectively.

But making the jump from one species to another isn’t easy, because successful viruses have to be tightly adapted to their hosts. To get into a host cell, a molecule on the virus’s surface has to match a receptor on the outside of the cell, like a key fitting into a lock. Once inside the cell, the virus has to evade the cell’s immune defenses and then commandeer the appropriate parts of the host’s biochemistry to churn out new viruses. Any or all of these factors are likely to differ from one host species to another, so viruses will need to change genetically — that is, evolve — in order to set up shop in a new animal.

Host switching actually involves two steps, though these can overlap. First, the virus has to be able to invade the new host’s cells: That’s a minimum requirement for making the host sick. But to become capable of causing epidemics, the virus also has to become infectious — that is, transmissible between individuals — in its new host. That’s what elevates a virus from an occasional nuisance to one capable of causing widespread harm.

SARS-CoV-2 shows these two stages clearly. Compared with the virus in bats, both the virus that infects people and a close relative in pangolins carry a mutation that changes the shape of the surface “spike protein.” The alteration is right at the spot that binds to host cell receptors to let the virus in. This suggests that the mutation first arose either in pangolins or an as yet unidentified species and happened to allow the virus to jump over to people, too.

But SARS-CoV-2 carries other changes in the spike protein that appear to have arisen after it jumped to people, since they don’t occur in the bat or pangolin viruses. One is in a region called the polybasic cleavage site, which is known to make other coronaviruses and flu viruses more infectious. Another appears to make the spike protein less fragile, and in lab experiments with cell cultures, it makes the virus more infectious. The mutation has become more common as the Covid-19 pandemic goes on, which suggests — but does not prove — that it makes the virus more infectious in the real world, too. (Fortunately, though it may increase spread, it doesn’t seem to make people sicker.)

\"Structure — A recent mutation alters the SARS-CoV-2 spike protein to make it less fragile (the altered bits are shown as colored blobs). This added robustness appears to make the virus more infectious. Three sites are shown because the spike protein is composed of three identical subunits that bind together.
\n \n \n \n

This evolutionary two-step — first spillover, then adaptation to the new host — is probably characteristic of most viruses as they shift hosts, says Daniel Streicker, a viral ecologist at the University of Glasgow. If so, emerging viruses probably pass through a “silent period” immediately after a host shift, in which the virus barely scrapes by, teetering on the brink of extinction until it acquires the mutations needed for an epidemic to bloom.

Streicker sees this in studies of rabies in bats — which is a good model for studying the evolution of emerging viruses, he says, since the rabies virus has jumped between different bat species many times. He and his colleagues looked at decades’ worth of genetic sequence data for rabies viruses that had undergone such host shifts. Since larger populations contain more genetic variants than smaller populations do, measuring genetic diversity in their samples enabled the scientists to estimate how widespread the virus was at any given time.

The team found that almost none of the 13 viral strains they studied took off immediately after switching to a new bat species. Instead, the viruses eked out a marginal existence for years to decades before they acquired the mutations — of as yet unknown function — that allowed them to burst out to epidemic levels. Not surprisingly, the viruses that emerged the fastest were those that needed the fewest genetic changes to blossom.

SARS-CoV-2 probably passed through a similar tenuous phase before it acquired the key adaptations that allowed it to flourish, perhaps the mutation to the polybasic cleavage site, perhaps others not yet identified. In any case, says Colin Parrish, a virologist at Cornell University who studies host shifts, “by the time the first person in Wuhan had been identified with coronavirus, it had probably been in people for a while.”

It was our bad luck that SARS-CoV-2 adapted successfully. Many viruses that spill over to humans never do. About 220 to 250 viruses are known to infect people, but only about half are transmissible — many only weakly — from one person to another, says Jemma Geoghegan, an evolutionary virologist at the University of Otago, New Zealand. The rest are dead-end infections. Half is a generous estimate, she adds, since many other spillover events probably fizzle out before they can even be counted.

\"Pallbearers — Funeral for a US soldier who died of influenza in Russia in 1919. The 1918-1920 pandemic killed an estimated 50 million people worldwide.
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CREDIT: US NATIONAL ARCHIVES
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Getting nicer — or nastier

SARS-CoV-2, of course, is well past the teetering stage. The big question now is: What happens next? One popular theory, endorsed by some experts, is that viruses often start off harming their hosts, but evolve toward a more benign coexistence. After all, many of the viruses we know of that trigger severe problems in a new host species cause mild or no disease in the host they originally came from. And from the virus’s perspective, this theory asserts, hosts that are less sick are more likely to be moving around, meeting others and spreading the infection onward.

“I believe that viruses tend to become less pathogenic,” says Burtram Fielding, a coronavirologist at the University of the Western Cape, South Africa. “The ultimate aim of a pathogen is to reproduce, to make more of itself. Any pathogen that kills the host too fast will not give itself enough time to reproduce.” If SARS-CoV-2 can spread faster and further by killing or severely harming fewer of the people it infects, we might expect that over time, it will become less harmful — or, as virologists term it, less virulent.

This kind of evolutionary gentling may be exactly what happened more than a century ago to one of the other human coronaviruses, known as OC43, Fielding suggests. Today, OC43 is one of four coronaviruses that account for up to a third of cases of the common cold (and perhaps occasionally more severe illness). But Fielding and a few others think it could also have been the virus behind a worldwide pandemic, usually ascribed to influenza, that began in 1890 and killed more than a million people worldwide, including Queen Victoria’s grandson and heir.

\"Cartoon — “Everyone has influenza,” says the headline in a French publication from January, 1890.
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CREDIT: WELLCOME COLLECTION
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Scientists can’t prove that, because no virus samples survive from that pandemic, but some circumstantial evidence makes the case plausible, Fielding says. For one thing, people who were infected in the 1890 pandemic apparently experienced nervous-system symptoms we now see as more typical of coronaviruses than of influenza. And when Belgian researchers sequenced OC43’s genome in 2005 and compared it to other known coronaviruses, they concluded that it likely originated as a cattle virus and may have jumped to people right around 1890. They speculated that it may have caused the 1890 pandemic and then settled down to a less nasty coexistence as an ordinary cold virus.

Other evolutionary biologists disagree. The pandemic certainly faded as more people became immune, but there’s no solid evidence that OC43 itself evolved from highly virulent to mostly benign over the last century, they say. Even if it did, that does not mean SARS-CoV-2 will follow the same trajectory. “You can’t just say it’s going to become nicer, that somehow a well-adapted pathogen doesn’t harm its host. Modern evolutionary biology, and a lot of data, shows that doesn’t have to be true. It can get nicer, and it can get nastier,” says Andrew Read, an evolutionary microbiologist at Penn State University. (Holmes is blunter: “Trying to predict virulence evolution is a mug’s game,” he says.)

To understand why it’s so hard to predict changes in virulence, Read says it’s important to recognize the difference between virulence — that is, how sick a virus makes its host — and its transmissibility, or how easily it passes from one host individual to another. Evolution always favors increased transmissibility, because viruses that spread more easily are evolutionarily fitter — that is, they leave more descendants. But transmissibility and virulence aren’t linked in any dependable way, Read says. Some germs do just fine even if they make you very sick. The bacteria that cause cholera spread through diarrhea, so severe disease is good for them. Malaria and yellow fever, which are transmitted by mosquitos, can spread just fine even from a person at death’s door.

Respiratory viruses, like influenza and the human coronaviruses, need hosts that move around enough to breathe on one another, so extremely high virulence might be detrimental in some cases. But there’s no obvious evolutionary advantage for SARS-CoV-2 to reduce its virulence, because it pays little price for occasionally killing people: It spreads readily from infected people who are not yet feeling sick, and even from those who may never show symptoms of illness. “To be honest, the novel coronavirus is pretty fit already,” Geoghegan says.

Nor are there many documented instances of viruses whose virulence has abated over time. The rare, classic example is the myxoma virus, which was deliberately introduced to Australia in the 1950s from South America to control invasive European rabbits. Within a few decades, the virus evolved to reduce its virulence, albeit only down to 70 to 95 percent lethality from a whopping 99.8 percent. (It has since ticked up again.)

But myxoma stands nearly alone, Parrish says. For instance, he notes, there is no evidence that recent human pathogens such as Ebola, Zika or chikungunya viruses have shown any signs of becoming less pathogenic in the relatively short time since jumping to humans.

\"A — After rabbits were introduced to Australia, their population exploded. “They are very plentiful here,” says the handwritten inscription on the back of this postcard from around 1930. Scientists eventually introduced the myxoma virus to control the rabbit plague.
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CREDIT: PHOTOGRAPHER PAUL C. NOMCHONG / NATIONAL MUSEUM OF AUSTRALIA
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The ones that went away

The faded nightmares of our past — pandemics that terrorized, then receded, such as SARS in 2003 and flu in 1918-20 and again in 1957, 1968 and 2009 — went away not because the viruses evolved to cause milder disease, but for other reasons. In the case of SARS, the virus made people sick enough that health workers were able to contain the disease before it got out of hand. “People who got SARS got very sick, very fast and were easily identified, easily tracked and readily quarantined — and their contacts were also readily identified and quarantined,” says Mark Cameron, an immunologist at Case Western Reserve University in Cleveland, who worked in a Toronto hospital during the height of the SARS outbreak there. That was never going to be as easy to do for Covid-19 because people who don’t show symptoms can spread the virus.

Flu pandemics, meanwhile, have tended to recede for another reason, one that offers more hope in our present moment: Enough of the population eventually becomes immune to slow the virus down. The H1N1 influenza virus that caused the 1918 pandemic continued as the main influenza virus until the 1950s, and its descendants still circulate in the human population. What made the virus such a threat in 1918-20 is that it was novel and people had little immunity. Once much of the population had been exposed to the virus and had developed immunity, the pandemic waned, although the virus persisted at a lower level of infections — as it does to this day. It appears less lethal now largely because older people, who are at greatest risk of dying from influenza, have usually encountered H1N1 influenza or something like it at some point in their lives and retain some degree of immunity, Read says.

With the new coronavirus, Parrish says, “we’re sort of in that 1918 period where the virus is spreading fast in a naive population.” But that will change as more people either catch Covid-19 or are vaccinated (if and when that becomes possible) and develop some level of immunity. “There’s no question that once the population is largely immune, the virus will die down,” Parrish says.

The question is how long that immunity will last: for a lifetime, like smallpox, or just a few years, like flu? In part, that will depend on whether the vaccine induces a permanent antibody response or just a temporary one. But it also depends on whether the virus can change to evade the antibodies generated by the vaccine. Although coronaviruses don’t accumulate mutations as fast as flu viruses, they do still change. And at least one, which causes bronchitis in chickens, has evolved new variants that aren’t covered by previous vaccines. But at this point, no one knows what to expect from SARS-CoV-2.

There is, at least, one encouraging aspect to all this. Even if we can’t predict how the virus will evolve or how it will respond to the coming vaccine, there is something all of us can do to reduce the risk of the virus evolving in dangerous ways. And it doesn’t involve any complicated new behaviors. “Viruses can only evolve if they’re replicating and transmitting,” Streicker says. “Anything that reduces the replication of a virus will in consequence reduce the amount of evolution that happens.” In other words, we can do our part to slow down the evolution of the Covid-19 virus by behaving exactly as we’ve been told to already to avoid catching it: Minimize contact with others, wash your hands and wear a mask.

\n","field_all_authors":"

\n \n \n \n By\n\n \n Bob Holmes\n \n \n \n \n 07.16.2020\n

\n","field_ar_article":{"arguments":[]},"field_author_bios":"

Bob Holmes is a science writer in Edmonton, Canada, who hopes not to contribute to the further evolution of SARS-CoV-2.

\n","field_banner_alt":"Collage showing viruses, historical photo of patients in hospital beds, photo of a woman wearing a mask and a bat, rabbit, mouse and camel.","field_banner_title":"Emerging viruses","field_caption":"

Many pathogens that afflict humankind spill over from natural reservoirs in animals.

\n","field_credit":"

CREDIT: KNOWABLE MAGAZINE

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How viruses evolve

Pathogens that switch to a new host species have some adapting to do. How does that affect the course of a pandemic like Covid-19?

\n By Bob Holmes \n \n

7.16.2020

Contrast that with the closely related coronavirus that causes Covid-19 today: more than 13,600,000 confirmed cases as of July 16, and more than 585,000 deaths.

Why did SARS go away while today’s coronavirus just keeps on spreading? Why, for that matter, did both these coronaviruses spill over into people at all, from their original bat hosts?

And just as vital as those questions is another: What happens next?

Steps to viral success

SARS-CoV-2 shows these two stages clearly. Compared with the virus in bats, both the virus that infects people and a close relative in pangolins carry a mutation that changes the shape of the surface “ spike protein.” The alteration is right at the spot that binds to host cell receptors to let the virus in. This suggests that the mutation first arose either in pangolins or an as yet unidentified species and happened to allow the virus to jump over to people, too.

Getting nicer — or nastier

The ones that went away

10.1146/knowable-071520-1

\n\n

Bob Holmes is a science writer in Edmonton, Canada, who hopes not to contribute to the further evolution of SARS-CoV-2.

This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.

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The Covid-19 pandemic has tightened our social circles and narrowed the scope of our lives in ways no one imagined just a year ago. But the lockdown also brought an unexpected solace: Everyone, it seems, turned to baking sourdough bread. Social media has been overflowing with photos of frothy sourdough starters — many of them named, like a family pet — and the fresh-baked loaves that result. And though peak sourdough may have passed, many a fridge still contains that jar of starter.

Most home sourdough bakers know that their starter contains a vibrant herd of microbes, which leaven and flavor their bread. But where conventional breads rely on a single species of baker’s yeast — the microbial equivalent of a cattle ranch — sourdough is more like the Serengeti, a diverse ecosystem of interacting yeasts and bacteria. The nature of that ecosystem, and hence the flavor of the bread, is a profound expression of a particular time and place. Scientists are beginning to discover that the microbes in a sourdough depend not just on the native microbial flora of the baker’s house and hands, but also on other factors like the choice of flour, the temperature of the kitchen, and when and how often the starter is fed.

“When we study sourdough science, we learn that we know remarkably little for a technology that’s — what? — 12,000 years old,” says Anne Madden, a microbiologist at North Carolina State University. But even that limited knowledge is enough to cast light on a diverse, tumultuous microbial world — and provide a few hints to home bakers hoping to up their game. (We probably still have plenty of time to be baking, alas.)

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Under the microscope, a sourdough starter is full of yeast cells, much smaller bacteria and bubbles of carbon dioxide produced by fermentation.

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CREDIT: JADWIGA B. PODOWSKA

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Rise of the microbes

Mix flour and water in a bowl and you have papier-mâché paste. But almost immediately, yeasts and bacteria from the environment and the flour itself begin feeding on the sugars in the flour, explains Erin McKenney, a microbial ecologist also at North Carolina State who has studied the events that unfurl as a sourdough starter forms. At first, just about any microbe can grow on this rich, new energy source, including spoilage bacteria. (That’s why brand-new sourdough starters often go through a black, putrid-smelling phase.)

But soon, conditions begin to change. One group of those early colonists begins to acidify the starter. By Day 3, these so-called lactic acid bacteria — named for one of the main acids they produce, which is also found in yogurt, cheese and other fermented milk products — have made the starter so acidic that many of the early colonists can’t survive, leaving only the lactic acid bacteria and a few acid-tolerant yeasts. This lactic acid, together with vinegary-smelling acetic acid, gives sourdough its characteristic tang.

It may also improve the nutritional quality of the bread, says microbiologist Guylaine Lacaze of the Belgian bakers’ supply and consulting company Puratos (she is aware of four as-yet-unpublished studies on the topic). The increased acidity activates an enzyme, phytase, that makes minerals like calcium and phosphate more available, she says.

By Days 10 to 14, the starter has settled into a stable state where yeasts and lactic acid bacteria grow vigorously, the yeasts producing enough carbon dioxide to leaven a loaf of bread. The starter is ready to use.

But the fact that new starters settle down within a couple of weeks doesn’t mean that they all end up with the same set of microbes. In one recent study, Madden and her colleagues shipped bags of the same flour to 18 professional bakers around the world, who then used the flour to create starters in their own kitchens using identical techniques. About a month later, the bakers and their starters convened in Belgium, where researchers used DNA sequencing to identify the microbes in each starter.

Even though all the bakers started with the same flour, their starters were all different. Most contained various strains of common baker’s yeast, Saccharomyces cerevisiae, along with a host of other yeasts in varying proportions, they found. The starters also contained a wide range of lactic acid bacteria, mostly in the genus Lactobacillus — though once again, the details varied widely from one starter to the next. Most microbes appeared to have come from the flour — a different draw each time — though a few also originated with the baker’s hands or kitchen.

This chart shows yeasts (left) and lactic acid bacteria (right) that make up 18 different sourdough starters created by professional bakers around the world. The bakers began their starters with identical flour, yet ended up with dramatically different collections of sourdough microbes. Each genetically distinct species or strain is shown in a different color; note that the white space at the top of each bar represents microbes too rare to track separately.
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Other research groups in Europe have seen similar diversity. “My conclusion is that every sourdough is different,” says Marco Gobbetti, a microbiologist at the Free University of Bozen-Bolzano in Italy. Indeed, he suspects, a constant flux of species may be the norm for any given sourdough over time, though what little evidence is available is still equivocal. This casts some doubt on treasured heirloom sourdoughs, some of which have been passed down for generations. While their owners may like to think that they’re baking with the same microbes their ancestors used, Gobbetti is skeptical.

But even if every sourdough is different, might they fall into several distinct groups based on the microbes that are present, in much the same way that terrestrial plant communities can be grouped into grasslands and forests despite a changing mix of species? The answer to that question might be coming soon. Elizabeth Landis, a microbiologist at Tufts University in Boston, and her colleagues (including Madden and McKenney) identified the microbes in 560 starters submitted by bakers around the world, then looked for recurrent groupings of microbes. Some species do appear to co-occur frequently, they found, perhaps because they specialize in feeding on distinct sugars. The yeast Kazachstania humilis, for example, can’t use the sugar maltose, which is therefore available for the lactic acid bacteria. (The paper describing these results is still under review, so Landis isn’t sharing details just yet.)

Each microbial community seems to produce its own unique flavor profile, too, McKenney says. Some produce more lactic acid, which gives a yogurty flavor; others yield a sharper, more vinegary note from lots of acetic acid. And because each species of microbe has slightly different metabolic pathways, each is likely to add other flavorful metabolic byproducts to the mix — a big reason sourdough tends to have a subtler, more complex flavor than ordinary bread. “You could compare it to one single flower compared to a nice bouquet of different flowers. The complexity of all these different compounds is what you find in a sourdough bread,” says Karl De Smedt, who maintains a library of sourdough starters at Puratos.

Care and feeding

Not everyone agrees that sourdough microbial communities are so variable. In commercial bakers’ sourdoughs, which are fed daily or even more often, the microbes always have plenty of food. That creates a race, with the fastest-reproducing microbes dominating over time, says Michael Gänzle, a food microbiologist at the University of Alberta, Canada. In the long run, he says, the winners are the yeast Kazachstania and the lactic acid bacterium Lactobacillus sanfranciscensis (recently renamed Fructilactobacillus sanfranciscensis).

That’s not necessarily good news for the resulting bread: L. sanfranciscensis grows fastest because it has one of the smallest genomes among lactic acid bacteria, which means it has fewer metabolic pathways and thus fewer flavor-producing by-products than other bacteria, Gänzle says. (Score one for home sourdoughs, which Landis says might be more diverse.)

But the flavor of a sourdough bread depends on more than just the species of microbes present in the starter. “You can have really different sourdoughs even if the microflora is the same,” says Lacaze. “It depends also on the recipe of the sourdough, the parameters of the culture.” Stiffer starters — that is, those made with a lower proportion of water — trap more oxygen within the dough, and this encourages lactic acid bacteria to produce sharper-tasting acetic acid; in runnier starters, the same bacteria produce softer-tasting lactic acid.

\"Photo — Little details make a big difference to a starter’s flavor. The starter on the left is made with less water. This makes a stiffer starter that traps more air, leading the bacteria in the starter to make more acetic acid, which gives a sharp flavor. The runnier starter on the right yields a milder-tasting loaf.
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CREDIT: THE COOKING LAB, LLC
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Temperature matters, too. Lactic acid bacteria do best in relatively warm conditions, for example, so fermenting in a warm kitchen makes for a sourer dough, while cooler conditions lead to more of the fruity flavors produced by the yeast. Moreover, lactic acid bacteria, despite what you’d think, aren’t fond of highly acid environments. Home bakers who leave an acidic starter in a cold fridge for weeks between bakings can find they end up with a blander bread that lacks the distinctive tang contributed by the bacteria. (Pro tip: If you’re going to leave your starter in the fridge for longer than a week, make sure to refrigerate it immediately after adding fresh flour, when it’s least acidic. That, says Lacaze, will help the lactic acid bacteria survive the prolonged cold to acidify the rising dough.)

One of the biggest ways that bakers can influence the flavor of their sourdough bread is through their choice of flours for the starter. To demonstrate this, McKenney and her team made four starters each from 10 different grains. Because grains differ in the mix of sugars they make available to sourdough microbes — corn, for example, lacks a starch-digesting enzyme that creates maltose — they might lead to different sets of microbes and, hence, different flavors. And that’s exactly what McKenney found (again, the results are not yet published). Starters made from amaranth flour tended toward meaty, toasty aromas. Those made from teff (an African grain) and sorghum gave fermented smells, while emmer and buckwheat gave more vinegary starters.

So far, McKenney and other sourdough researchers have taken only baby steps toward designer sourdoughs: Their science has not yet caught up to folk wisdom. “People would like to know step by step: ‘How do I make the end product I desire?’” McKenney says. “We can’t begin to offer anything that’s better than common baking knowledge or the best practices you learn from blogs or talking to friends.”

More answers could be coming soon, thanks to new citizen-science initiatives. McKenney, Madden and their colleagues run the Wild Sourdough Project, which invites home bakers to experiment with flours and growing conditions and report their results. Similarly, Puratos has launched the Quest for Sourdough, where anyone from newbies to professionals can register their sourdough. Those with particularly interesting or unique starters might be invited to submit them to Puratos’s sourdough library for further analysis.

But sourdough is interesting to more than just bakers. Sourdough and other food fermentations such as those that give us cheese, sauerkraut and kimchi provide relatively simple, easy-to-handle model ecosystems for studying microbial ecology more generally. “There’s lots of insights you can gain from studying fermented foods that you can then transfer to more complex microbial communities as well,” says Paul Cotter, a microbiologist at the Teagasc Food Research Centre in Ireland, and co-author of an article on food microbiology in the Annual Review of Food Science and Technology.

Sourdough offers an additional benefit, especially relevant in pandemic times when the microbial world seems so full of threat. “Sourdough is this one space where we all agree, as a society, that microbes are helping us do wonderful things,” Madden says. “If you love sourdough, you love wild microbes in our lives.”

Editor's note: This story was updated on August 13, 2020, to correct an error in the authorship of a study. The study, on the microbial diversity of sourdough starters originating from identical bags of flour, should have been attributed to Anne Madden and her colleagues, not Erin McKenney and her colleagues, as was originally stated.

Editor’s note: This story was updated on August 18, 2020, to correct an error. The original stated that baker’s yeast could not use the sugar maltose. It can, although several other yeasts common in sourdough, such as Kazachstania humilis, cannot.

\n","field_all_authors":"

\n \n \n \n By\n\n \n Bob Holmes\n \n \n \n \n 08.12.2020\n

\n","field_ar_article":{"arguments":[]},"field_author_bios":"

Bob Holmes is a science writer based in Edmonton, Canada. His sourdough died.

\n","field_banner_alt":"A foaming jar of sourdough starter stands next to a sliced loaf of bread.","field_banner_title":"Sourdough Starter","field_caption":"

Everyone, it seems, has tried sourdough during the lockdown. But that ubiquitous jar of starter contains a dynamic microbial ecosystem that scientists are only beginning to understand.

\n","field_credit":"

CREDIT: ISTOCK.COM / LEONORI

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Microbial secrets of sourdough

It all starts with a community teeming with yeasts and bacteria — but what’s really happening? Scientists peer into those jars on the kitchen counter to find out.

\n By Bob Holmes \n \n

8.12.2020

Rise of the microbes

Care and feeding

10.1146/knowable-081120-1

\n\n

Bob Holmes is a science writer based in Edmonton, Canada. His sourdough died.

This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.

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On a cool afternoon, I enter a shaded path leading into a small nature preserve near my home in southern Maine. I tread slowly beneath the pines, eager to explore beyond the confines of my pantry and home office after weeks of Covid-19 stay-at-home orders.

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As I crunch over dead leaves into the shadows, I’m pulled farther in by the sound of rushing water, and soon a wide stream emerges to the left. I have never visited this seven-acre patch of woods before, so I soak up its newness. The moist twigs lit by dappled sunlight, the large clumps of dead leaves damming up eddies: They relieve some of the weight of the pandemic.

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All this debris may look like a mess, but it’s actually a sign of health. A mucky stream breeds new life; a sterile stream breeds nothing. I stare at one brown leaf, hanging and wagging in the current. Where’s it headed? What new life will it brew?

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What will come of this dead leaf?

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For me, it’s an idle thought. For Jane Marks, it’s all in a day’s work. As a biologist at Northern Arizona University in Flagstaff who studies leaf litter, she’s been tromping through streams and contemplating messy debris for decades and, when we speak over the phone from our home offices, she tells me that it never gets old. “There are always little surprises,” she says.

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Dead leaves, Marks explains, provide a primary food base for life all the way up the food chain in and around streams, from the fungi and bacteria that initially colonize the leaves, and the insects that chew them, down to the birds and fish that eat those insects, and so on. Different organisms prefer different types of leaves, so the greater the variety of trees along a stream bank, the greater variety of life they support.

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These “brown” or “dead” food webs can be far more expansive than the “green” food webs a leaf nourishes when it’s still alive, Marks says. A fresh leaf might feed caterpillars or beetles that in turn feed insect-gobbling carnivores, but the pool of nutrients that dead leaves release by decaying in water adds another dimension to their contribution. “Understanding what happens once it’s dead,” she says, “is actually as important or more important than understanding what’s happening when it’s alive.”

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The nuances are many, Marks writes in an article titled “Revisiting the Fates of Dead Leaves That Fall into Streams” in the Annual Review of Ecology, Evolution, and Systematics. No two trees produce the same two leaves, so she is working to understand which species produce more nutritious or digestible leaves, and which groupings of trees are best suited to feed different types of aquatic ecosystems. Riparian zones — areas on land that border rivers and streams — make up only a fraction of the landmass on any given continent, but often contain an outsized dose of biodiversity that fuels the ecosystems beyond.

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So Marks’s findings have practical applications that belie the simple wag of that brown leaf I observe on my stroll, as ecologist Amy Marcarelli explains when I call her some days later: Knowing how leaf litter breaks down helps inform efforts ranging from fisheries management to water quality improvements to large-scale river restoration projects.

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The research also has implications for climate science, adds Marcarelli, who studies aquatic ecosystems at Michigan Technological University. Dead leaves can release carbon dioxide into the atmosphere when they decay. Or they can trap carbon dioxide safely underground if they become buried and remain unconsumed. So understanding these “fates of dead leaves that fall into streams” — poetical phrasing borrowed from a paper published in the 1970s — “is really important,” Marcarelli says.

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Marks attacks the problem by packing different types of leaves into small mesh bags, leaving them in streams and observing their eventual disappearance over the course of several months.

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First, she says, newly fallen leaves behave like a tea bag in water — some carbohydrates and sugars seep out almost immediately and float downstream. But plenty remains behind, and that provides fodder for the fungi that now flourish. The fungi make the leaf easier for bacteria to break down and then, after about four to six days, insects start to join in on the feeding frenzy.

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The first insects to arrive are usually small gnats, Marks says. Then bigger insects called shredders descend, with mouthparts designed to tear apart big chunks of leaves. Shredders include the larvae of insects like caddisflies and stoneflies, and tend to be quite messy. They leave behind a trail of smaller particles — which feed another group of insect larvae called collector/gatherers. Those, in turn, leave behind particles that pass on to animals like freshwater mussels or black fly larvae that filter food directly out of the water. The leaf, Marks says, “just keeps getting processed and processed until it’s gone.”

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This whole breakdown can take as much as three to four months in relatively warm rivers like the ones she studies in the southwestern United States, or up to a year in colder waters. But depending on the tree species, events can unfold far faster. So maintaining a diversity of trees along streambanks helps to ensure that food sources for insects — and the animals that eat them — persist through the year and don’t disappear all at once.

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This is the type of information that land managers might use when choosing what trees to plant when restoring degraded stream- and riverbanks. But focusing just on species diversity may not be enough: Individual trees within a given species can also differ widely in their nutritiousness and digestibility, explains biologist Thomas Whitham of Northern Arizona University, who collaborates with Marks.

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Over the past decade or so, Whitham and colleagues have been studying the molecular and genetic diversity of trees and have found that variability within a species can be greater than between species. Leaves from two different narrowleaf cottonwood trees, for example, can contain up to a tenfold difference in difficult-to-digest compounds called tannins, with one leaf containing 3 percent tannins and another leaf 33 percent. “People thought, you see one cottonwood, you’ve pretty much seen them all,” he says. “But that’s not true.”

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Whitham has partnered with the Nature Conservancy, the Grand Canyon Trust, the Bureau of Land Management and other groups to help plant hundreds of thousands of trees in restoration projects across the Southwest. With cottonwood-leaf lessons in mind, his team works to understand which trees are especially digestible or nutritious and to help land managers plant an array of types that, together, can support the needs of the ecosystems they’re trying to restore. “Diversity in the plants will have ripple effects on everything around them,” he says.

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Now the warming climate has added another thread to these rippling dynamics — one that may begin to unravel these systems. Warmth increases the rate of microbial activity, so fungi and bacteria may become more voracious consumers of leaves in a warmer world. This may leave less food available for insects and the creatures that eat the insects, says Amy Rosemond, an ecologist at the University of Georgia who studies the effects of global change on rivers and streams. “As soon as a stream increases 2 degrees C, you’ve lost some of that carbon that would otherwise be going into the food web,” she says.

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She points me to a paper that refers to aquatic food chains as “tangled webs,” and she talks about rivers and streams as the “plumbing” of our continent. I sense a preponderance of lyricism within the science that explores the fates of dead leaves in streams — more than you typically find in academic papers. I ask Rosemond about this, and she agrees that poeticism has found its way into the field. “I think scientists are artists,” she says. “Ecologists see holism, and are drawn to nature because of its beauty and its connections.”

\n\n

Now, on my daily strolls in the woods during this pandemic, the connections bubble up when I pause to take in a mucky scene. The old tree that has fallen across the stream near my home isn’t just a thing in the way — it is a dam for leaves that stores food all winter for the fungi and bacteria, the shredders and the gatherers that emerge in the spring, and the adult insects and the birds that eat them. Without those dams, this stream would be like a lifeless pipe.

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For a while, Marks says, pipes are what many people thought they wanted out of rivers and streams. As the world industrialized, they wanted streams to be easy to get water from, or easy to get boats through. They cleared away the fallen branches and let those leaves wash away. Today, river restoration projects often deliberately drop dead trees into streams to dam up the leaves and keep them in place. “We have since realized all this natural complexity is really, really important to everything that lives in it,” Marks says. Dead leaves, and the nourishment they store, remind us that there’s beauty and life to be found in disorder and decay.

\n\n","field_all_authors":"

By Laura Poppick 08.06.2020

\n\n","field_author_bios":"

Laura Poppick is a freelance science and environmental journalist based in Maine who has always enjoyed mucking in streams. Twitter: @laurapoppick

\n\n","field_banner_alt":"Photograph showing a close-up of red and orange maple leaves floating in water.","field_banner_title":"Leaves in water","field_caption":"

Dead leaves in streams may look like so much litter but they play pivotal roles in how energy moves through ecosystems.

\n\n","field_credit":"

CREDIT: HYBRID / UNSPLASH

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\n\n

The life that springs from dead leaves in streams

\n\n

A crunchy brown leaf may seem like an ending. But the food webs it supplies can be far more expansive than the ones it nourished when it was young, green and in its prime.

\n\n

By Laura Poppick

\n\n

8.6.2020

\n\n

What will come of this dead leaf?

\n\n

Marks attacks the problem by packing different types of leaves into small mesh bags, leaving them in streams and observing their eventual disappearance over the course of several months.

\n\n

10.1146/knowable-080620-1

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Laura Poppick is a freelance science and environmental journalist based in Maine who has always enjoyed mucking in streams. Twitter: @laurapoppick

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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.

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$\"Knowable$

\n\n","field_tagline":"A crunchy brown leaf may seem like an ending. But the food webs it supplies can be far more expansive than the ones it nourished when it was young, green and in its prime.","field_xml_enabled":"1"},"relationships":{"field_ar_related_articles":{"data":[{"id":"1820","type":"paragraphs"},{"id":"1821","type":"paragraphs"},{"id":"1822","type":"paragraphs"}]},"field_banner":{"data":{"id":"1929","type":"images"}},"field_footer_articles":{"data":[{"id":"sustainability/2017/photosynthesis-fix","type":"articles"},{"id":"living-world/2018/self-made-beauty-centriole","type":"articles"}]},"field_import_zip":{"data":{"id":"1930","type":"images"}},"field_topic":{"data":{"id":"living-world","type":"topics"}},"field_topics":{"data":[{"id":"living-world","type":"topics"}]}}},{"id":"1954","type":"images","attributes":{"title":"mud-origins-1600x600.jpg","filename":"mud-origins-1600x600.jpg","uri":"public://articles/520/mud-origins-1600x600_1.jpg","styles":{"134_y":"https://www.knowablemagazine.org/sites/default/files/styles/134_y/public/articles/520/mud-origins-1600x600_1.jpg?itok=rxVrLlnD","1600_600":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/520/mud-origins-1600x600_1.jpg?itok=3R7JbpCs","285_205":"https://www.knowablemagazine.org/sites/default/files/styles/285_205/public/articles/520/mud-origins-1600x600_1.jpg?itok=RhWFxEJv","305_220":"https://www.knowablemagazine.org/sites/default/files/styles/305_220/public/articles/520/mud-origins-1600x600_1.jpg?itok=zlQiAZtD","400_y":"https://www.knowablemagazine.org/sites/default/files/styles/400_y/public/articles/520/mud-origins-1600x600_1.jpg?itok=UXQwF1HY","500_288":"https://www.knowablemagazine.org/sites/default/files/styles/500_288/public/articles/520/mud-origins-1600x600_1.jpg?itok=eJ4VLRL2","645_552":"https://www.knowablemagazine.org/sites/default/files/styles/645_552/public/articles/520/mud-origins-1600x600_1.jpg?itok=l6Oppx4_","750_y":"https://www.knowablemagazine.org/sites/default/files/styles/750_y/public/articles/520/mud-origins-1600x600_1.jpg?itok=4V04YSWa","large":"https://www.knowablemagazine.org/sites/default/files/styles/large/public/articles/520/mud-origins-1600x600_1.jpg?itok=8mrll9CY","linkit_result_thumbnail":"https://www.knowablemagazine.org/sites/default/files/styles/linkit_result_thumbnail/public/articles/520/mud-origins-1600x600_1.jpg?itok=uk9xMVQK","medium":"https://www.knowablemagazine.org/sites/default/files/styles/medium/public/articles/520/mud-origins-1600x600_1.jpg?itok=CYQH-lpP","thumbnail":"https://www.knowablemagazine.org/sites/default/files/styles/thumbnail/public/articles/520/mud-origins-1600x600_1.jpg?itok=apg8OqD8"},"filemime":"image/jpeg","filesize":"338017","status":"1"}},{"id":"living-world/2020/origin-mud","type":"articles","attributes":{"title":"The origin of mud","nid":"520","created":"1597700192","revision_default":"1","path":"606","body":"

Years ago, geologist Neil Davies traveled to Bolivia to pick through heaps of fossilized fish. He wanted to know more about the ancient shoreline these fish swam along roughly 460 million years ago, and perhaps learn how they died. The fish, he found, appeared to have been choked by muddy sand that rivers washed rapidly into the sea, maybe during a storm.

Similar heaps of smothered fish appear elsewhere around the world in rocks of similar age. This was before plants had colonized continents, so riverbanks had no roots or stems that could trap muddy sediments on land.

Magnify this effect globally, and the impacts would have been substantial — not just on coastal life but on the landscape of the entire planet. Before plants, rivers would have stripped continents of silt and clay — key constituents of mud — and sent these sediments to the seafloor. This would have left continents full of barren rock, and seas with smothered fish.

Once plants arrived on land, things began to change. Mud clung to vegetation along riverbanks and stuck around rather than shuttling straight to the seafloor. Davies, now at the UK’s University of Cambridge, and his colleagues have found that the expansion of land plants between about 458 million and 359 million years ago coincides with a more than tenfold increase in mud on land — and a significant shift in the ways that rivers flowed. The arrival of first plants and then mud “fundamentally changed the way the world operates,” he says.

\"A — The rise of plants on land corresponds with a rise of mudrock in the geologic record. Mud began accumulating with the appearance of some of the earliest, low-lying plants, and then piled up in larger quantities once trees and shrubs evolved.
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Life evolved tools to cope with the new muckiness and new river shapes, resulting in a diversification of life and landscapes that persists to this day. Plants are responsible for much of this change, but mud contributed too, by adding a cohesiveness to the continents — unlike sand, wet mud sticks together.

Davies is now working to figure out whether early plants increased the creation of mud, trapped more of it in place, or played both roles. It’s a story worth getting straight, says Woodward Fischer, a geobiologist at the California Institute of Technology in Pasadena. “Mud is one of the most common, abundant things you can think of,” he says. “The recognition that for most of Earth history it was not like that is a big deal.” The research could also help inform modern-day decisions around river engineering projects like dam construction, Fischer says. Understanding the ways that vegetation manipulates river flow and sediment buildup could help prevent some of the failures that have contributed to flooding along the Mississippi River and other major waterways across the world. “Every little bit that we can do better there has huge impacts,” he says.

Of mud and riverbanks

When geologists talk about mud, they’re referring to tiny particles that stick together when wet. Those particles have often broken down from larger rocks over time due to the forces of wind, rain, ice and snow. Fungi and microbes can break down rock and form mud, too.

Before plants arrived on land, mud was around — it was just mostly sent to the seafloor by rivers. Once plants showed up, they not only held sediments in place but their roots also physically broke down rock and released chemicals that further crumbled it. In these ways, plants accelerated what geologists refer to as the “continental mud factory.”

Since the 1960s, geologists have noticed that rivers that flowed before plants arrived on land often look different in the geological record than those that formed once continents greened. The earliest rivers resembled those that tumble along the gravelly coast of Alaska today, says Taylor Perron, an earth scientist at the Massachusetts Institute of Technology in Cambridge who wrote about the factors that control landscape formation in the 2017 Annual Review of Earth and Planetary Sciences.

Those gravelly Alaskan rivers have many channels that braid across sand banks, continually slumping and forming more channels as they periodically overflow — like rivulets at the edge of a beach. Without anything anchoring these riverbanks in place, they continuously collapse to form new channels. But the arrival of plants kept that erosion at bay — and mud added to the riverbanks’ cohesion — so rivers were less likely to slump into these braided forms. Instead, they developed a single channel that meandered through the landscape in a cohesive “S” shape, like parts of the Mississippi and Amazon rivers do today. In this sense, the arrival of plants “is one of the best natural experiments in landscapes that has ever happened on Earth,” Perron says.

\"An — Vegetation along riverbanks can help stabilize those banks and produce a single channel that snakes through the landscape in an “S” shape, as sections of the Amazon River, shown here, do today. The geologic record suggests that such meandering rivers became more common on Earth once plants colonized land.
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CREDIT: NASA EARTH OBSERVATORY IMAGE BY JESSE ALLEN
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The shape of a river may seem trivial, but it has far-reaching effects on the life in and around it. Bends in a sinuous channel, for example, can alter the water’s temperature or chemistry, making it different from sections that run in a straight line and creating new microenvironments that plants and animals need to adapt to, Davies says.

Even the earliest plants, which resembled mosses, could have begun to alter how sediments accumulate on riverbanks, says Kevin Boyce, a paleontologist at Stanford University who co-wrote about the evolution of plants in the 2017 Annual Review of Earth and Planetary Sciences. “Those weren’t big trees,” Boyce says, “but they still would have influenced the movements of water” by slowing its flow. As plants evolved to become tree-sized by about 386 million years ago, they gained the power to slow wind. Fine particles caught up in winds would drop to the ground when gusts died in the branches, leaving more sediment caught among trunks and stems.

Life in the muck

This posed new challenges to animals like early millipedes and wormlike creatures. “Mud is providing a totally different medium for things to live in,” says Anthony Shillito, a geologist at the University of Oxford, UK.

To get through mud, an animal such as a worm creates cracks to shuffle through by contracting its body, extending it, squeezing water out of the way and moving forward. This is mechanically different from traveling through sand, which requires an animal to excavate material out of the way, Shillito says. So early land worms and insects would have had to evolve body parts equipped to deal with muckier movements.

And those movements, in turn, could have helped shape the mud itself, says Lidya Tarhan, a paleobiologist at Yale University. “The act of digging and excavating those burrows and keeping them clear can move around sediments and change the distribution of sediments and also affect the chemistry,” she says. For example, some invertebrates ingest sediments to extract nutrition, and chemical reactions in their guts can form fine particles that come out in their feces as mud.

\"Loops — Here are three examples of traces left in the fossil record by animal movements. It’s often not possible to figure out exactly what critter left what trace, because different types of animals can produce similar-looking traces. But studying the different patterns can offer information about how animals may have traveled through ancient landscapes. As early animals began to colonize land, some wormed or pushed their way through sediments (A and C), whereas others scratched their way along (B).
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CREDIT: A.P. SHILLITO & N.S. DAVIES / *GEOLOGICAL MAGAZINE* 2020
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But the strongest influence early burrowing animals likely had on their muddy environments, Tarhan says, would have been loosening up mud and allowing it to disperse within rivers and across landscapes. With the rise of single-threaded rivers, mud would have had more opportunities to spread onto floodplains. Such plains don’t develop as easily alongside braided rivers, whose banks easily collapse as waters rise, says Chris Paola, a sedimentologist at the University of Minnesota in Minneapolis.

Modern rivers that people have deforested show how the absence of vegetation can destabilize riverbanks and cause them to become less cohesive. Along California’s Sacramento River, for example, areas that farmers cleared for cropland are far more susceptible to erosion than areas that remain forested. Conservationists have worked to stabilize the river by planting more than a million seedlings along its banks.

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This footage from a laboratory experiment captures how vegetation growth along channels (in this case, alfalfa growing within an experimental flume) manipulates the shape of channel flow. As the alfalfa spreads, the channel transitions from a braided pattern to single-threaded pattern with a defined floodplain.

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CREDIT: MICHEL TAL

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Understanding the interplay of plants and mud in river flow can inform efforts to restore eroding rivers back to a more stable state. “If you don’t understand what’s driving the river into one state or another, it’s hard to do that well,” says Paola, who coauthored an article about restoring river deltas in the 2011 Annual Review of Marine Science. And since so much of life revolves around rivers today, it’s important to do that well.

But this has always been true. Life has always congregated around rivers, from the very first emergence of plants and animals onto land. That’s why the early accumulations of mud alongside rivers — and how mud influenced their flow — is nothing to throw dirt on.

“Once you take it out of the equation and imagine the world without as much mud on the land,” Davies says, “then it becomes a very different kind of planet.”

\n","field_all_authors":"

\n \n \n \n By\n\n \n Laura Poppick\n \n \n \n \n 08.17.2020\n

\n","field_ar_article":{"arguments":[]},"field_author_bios":"

Laura Poppick is a Maine-based freelance science journalist with a background in Earth history. Twitter: @laurapoppick

\n","field_banner_alt":"An aerial image of the Copper River flowing into the Gulf of Alaska, dumping clouds of sediment into the sea.","field_banner_title":"Copper River","field_caption":"

Before plants colonized land, many rivers braided across barren landscapes and dumped large loads of sediment into the sea, as the Copper River in Alaska does today.

\n","field_credit":"

CREDIT: NASA EARTH OBSERVATORY IMAGE BY ROBERT SIMMON AND JESSE ALLEN

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The origin of mud

For most of Earth’s history, hardly any of the mucky stuff existed on land. It finally started piling up around 458 million years ago, changing life on the planet forever.

\n By Laura Poppick \n \n

8.17.2020

Of mud and riverbanks

Life in the muck

“Once you take it out of the equation and imagine the world without as much mud on the land,” Davies says, “then it becomes a very different kind of planet.”

10.1146/knowable-081720-1

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Laura Poppick is a Maine-based freelance science journalist with a background in Earth history. Twitter: @laurapoppick

This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.

$\"Knowable$ \n\n","field_tagline":"For most of Earth’s history, hardly any of the mucky stuff existed on land. It finally started piling up around 458 million years ago, changing life on the planet forever.","field_xml_enabled":"1"},"relationships":{"field_ar_related_articles":{"data":[{"id":"1837","type":"paragraphs"},{"id":"1838","type":"paragraphs"},{"id":"1839","type":"paragraphs"}]},"field_banner":{"data":{"id":"1954","type":"images"}},"field_import_zip":{"data":{"id":"1955","type":"images"}},"field_topic":{"data":{"id":"living-world","type":"topics"}},"field_topics":{"data":[{"id":"physical-world","type":"topics"},{"id":"living-world","type":"topics"}]}}},{"id":"living-world","type":"topics","attributes":{"title":"Living World","bundle":"topics","field_nof":3,"tid":"1","description":"","weight":"1","path":"1","metatags":{"referrer":"origin","title":"Living World | Knowable Magazine | Annual Reviews","description":"","pocket-site-verification":"665d7e2e5dc1fa27727a154d5c4e80"},"field_pattern":"pattern-living","field_promote":"1"},"relationships":{"field_featured_articles":{"data":[{"id":"living-world/2020/microbial-secrets-sourdough","type":"articles"},{"id":"living-world/2020/life-springs-dead-leaves-streams","type":"articles"},{"id":"living-world/2020/origin-mud","type":"articles"}]}}},{"id":"1908","type":"images","attributes":{"title":"hydrothermal-vents-1600x600.jpg","filename":"hydrothermal-vents-1600x600.jpg","uri":"public://articles/506/hydrothermal-vents-1600x600.jpg","styles":{"134_y":"https://www.knowablemagazine.org/sites/default/files/styles/134_y/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=hqmcX4xD","1600_600":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=-ecxrbeI","285_205":"https://www.knowablemagazine.org/sites/default/files/styles/285_205/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=W6wwZ2Ab","305_220":"https://www.knowablemagazine.org/sites/default/files/styles/305_220/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=RKBgqn9i","400_y":"https://www.knowablemagazine.org/sites/default/files/styles/400_y/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=_1FZ3bQ2","500_288":"https://www.knowablemagazine.org/sites/default/files/styles/500_288/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=gNLgkc9g","645_552":"https://www.knowablemagazine.org/sites/default/files/styles/645_552/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=1U3OlvDj","750_y":"https://www.knowablemagazine.org/sites/default/files/styles/750_y/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=R-mZ-gCU","large":"https://www.knowablemagazine.org/sites/default/files/styles/large/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=pwSPOI29","linkit_result_thumbnail":"https://www.knowablemagazine.org/sites/default/files/styles/linkit_result_thumbnail/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=DybCNCQ_","medium":"https://www.knowablemagazine.org/sites/default/files/styles/medium/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=f2LzfiqT","thumbnail":"https://www.knowablemagazine.org/sites/default/files/styles/thumbnail/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=ZkwiK2km"},"filemime":"image/jpeg","filesize":"358223","status":"1"}},{"id":"physical-world/2020/searching-high-and-low-origins-life","type":"articles","attributes":{"title":"Searching high and low for the origins of life","nid":"506","created":"1595362640","revision_default":"1","path":"592","body":"
Hot, bubbling fissures in the deep, sunless ocean seem unlikely places for life at all, let alone life’s origin. Yet recent studies have shown that two essential ingredients — amino acids and primitive cell membranes — can form spontaneously and reliably near the hydrothermal vents found in seafloors. The discoveries bolster a hypothesis about life’s origins that some scientists have supported for decades.
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Hydrothermal vents are chemical hot springs near fault lines on the ocean floor. Some, called white smokers, have elaborate mineral pillars or chimneys that are full of tiny chambers in which chemical reactions can take place. At 158 degrees Fahrenheit (70 degrees Celsius), the vents are a bit hot for a bubble bath but, it turns out, just right for the formation of amino acids and structures that could serve as cell membranes.
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Scientists suspect that deep hot vents like these might have seeded life on Earth about 4 billion years ago. Some hydrothermal vents release alkaline fluids, which could supply the energy needed to build complex organic molecules. And the basic chemistry of life “appears to match what you might expect if life began in this hot, dark, chemical-energy-powered setting,” says earth system scientist Timothy Lenton of the UK’s University of Exeter, a coauthor of a 2017 article on ocean biogeochemistry in the Annual Review of Marine Science.
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The vent hypothesis is somewhat controversial, but recent experiments lend weight to it. In one, NASA astrobiologist Laurie Barge and her colleagues showed how amino acids, the building blocks of proteins, could have formed near alkaline vents. Barge, of the Jet Propulsion Laboratory in Pasadena, California, became interested in the origin of life on Earth while searching for life not on Earth. Geology and biology would be closely linked anywhere, she says — whether on another planet or in a deep-sea vent here on Earth.
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To learn whether life’s building blocks could have formed near ancient vents, Barge’s team created miniature vents in the laboratory. Their simulated ocean water contained ammonia, the simple organic molecule pyruvate and iron hydroxide minerals, all of which likely existed in Earth’s early oceans. The water was depleted of oxygen and adjusted to 158 degrees F, the temperature of white smokers. Within these simulated vents, the chemical conditions allowed electrons to flow between the iron minerals and pyruvate, yielding the amino acid alanine, the team reported last year in the Proceedings of the National Academy of Sciences.
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The researchers could regulate the amount of alanine produced by adjusting the ratios of different iron hydroxide minerals to control how many electrons the iron released — like “a dial that could be tuned up or down,” Barge says. Electrons flow continuously from alkaline vents, providing a constant source to trigger chemical reactions.
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$\"Short$
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Astrobiologist Laurie Barge has recreated miniature hydrothermal vents in her NASA laboratory. This time-lapse video shows mineral chimneys forming within a warm brew of seawater and a few simple, primordial molecules. Barge found she could generate the amino acid alanine, one of the building blocks of proteins, in this set-up.
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CREDIT: NASA / JPL-CALTECH / FLORES
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Creating life’s building blocks
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Amino acids are important, but life is organized in cells — and cells can’t operate without a cell membrane. In the second experiment, biochemist Nick Lane at University College London and his colleagues showed how primitive membranes could form near alkaline vents.
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Lane used a laboratory replica of ancient deep-sea conditions to determine whether lipid-surrounded bubbles called vesicles — a sort of protocell — could form there. His team added 14 fatty acids and other chemicals, which would likely have been present in the early ocean, to acidic, simulated seawater. The scientists adjusted the liquid to be alkaline, making the chemicals go into solution. When the researchers slowly mixed the solution with seawater, the fatty acids assembled into vesicles. Vesicles formed most readily in conditions strikingly like white smokers — at 158 degrees F with strong alkalinity, the scientists reported in November in Nature Ecology & Evolution.
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Earlier studies had failed to form vesicles in hot, alkaline salt water — but that’s because they used fewer types of fatty acids, says Sean Jordan, a biogeochemist at University College London and a coauthor of the paper. His team used a large variety of them, which provided more ways for them to bond with one another.
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$\"Two$
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These microscope images show small, lipid-surrounded vesicles that formed in a lab at University College London when researchers mixed various fatty acids and other chemicals under conditions like those at a deep-sea hydrothermal vent. At left, the vesicles appear bright green; at right, they are magnified to show their blobby structures. These experiments demonstrated for the first time that vesicles — which are required for primitive cells — can form under the conditions found in hydrothermal vents.
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CREDIT: S.F. JORDAN ET AL / NATURE ECOLOGY & EVOLUTION 2019
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Some scientists aren’t convinced that life originated at a deep, alkaline hydrothermal vent. David Deamer, a biophysicist at the University of California, Santa Cruz, is one of several who say that salty ocean water would destroy the fatty acids needed to create cell membranes. He has shown that vesicles can form in freshwater — no deep-sea vents needed — by wetting and drying fatty acids. He offers the example of blowing soap bubbles. Soap is disordered in a solution with water, but blow a puff of air into it and the molecules assemble themselves into a membrane.
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Imagine a freshwater hot spring, where the surrounding ground gets damp after a rain and then periodically dries out. As things dry up, the compounds dissolved in the water become more concentrated. When drying removes water molecules, energy is released, creating the bonds that allow complex organic molecules to form.
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Another point in favor of the freshwater model is the origin of the first self-replicating molecules, Deamer says. Organisms must have a way to pass down information to the next generation if they are to reproduce; many scientists think that RNA was the first molecule capable of this. Years ago, Deamer and his colleagues created complex molecules that functioned like RNA by wetting and drying simple organic molecules in shallow freshwater pools. The drying process organized molecules to be more complex, without requiring an external jolt of energy.
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The story isn’t so simple, though. Both research camps have struggled to show that the basic biological molecules they make in the lab would actually function inside living organisms. Still, the hydrothermal vent proponents say they have all the right ingredients — including the energy needed to kickstart life. White smokers can supply energy in two ways, and one or both could have provided the power needed to build complex organic molecules.
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$\"A$
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Some scientists think that life began not at a marine vent, but at freshwater hot springs on Earth’s surface. This geothermal pool in Hveravellir, Iceland, may represent that kind of environment.
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CREDIT: FILIP FUXA / SHUTTERSTOCK
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The first happens when alkaline fluids spurt out of the seafloor and collide with acidic ocean water. This pH gradient creates a minor electric charge across the vent chimney. (In another study, Barge lit a small LED by linking hydrothermal chimneys together with wires.) Earth’s early oceans were more acidic than today, suggesting there could have been plenty of energy available at deep-sea vents.
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The other way that alkaline vents supply energy is by feeding a process in which electrons flow between chemicals in the ocean and rocks. This underwater electrical current could have driven the first life-giving chemical reactions. “Electricity is necessary to the origin of life,” says Lars Peter Nielsen, an electromicrobiologist at Aarhus University in Denmark. “Electricity makes it all come together.”
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Perhaps the most convincing argument for a marine origin of life is timing. Studies that track how life forms have evolved suggest that the earliest life on Earth emerged about 4 billion years ago. That timeline means life almost certainly originated in the ocean, Lenton says. The first continents hadn’t formed 4 billion years ago, so the surface of the planet was almost entirely ocean.
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Some of the oldest evidence for life on Earth comes from ancient chemical signatures and fossils in sedimentary rocks in Canada, which likely formed on the ocean floor. One study, reported in 2017 in Nature, even found tube-like fossils that look like microorganisms living near hydrothermal vents today — but in rocks that are at least 3.77 billion years old.
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Deamer argues that there would have been some landmasses 3.5 billion to 4 billion years ago, with the flanks of volcanoes emerging from the water. And freshwater pools could have formed on those landmasses through rainfall. If that’s plausible, says Deamer, so is a freshwater origin of life on Earth.
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Whether life originated in the deep ocean or shallow terrestrial pools remains to be seen. But it now seems likely that crucial organic molecules, and the membranes to hold them, could have been generated using the geochemistry of early Earth.
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By Anne N. Connor 07.21.2020
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Anne N. Connor is a science writer newly relocated to Vermont. Reach her at https://annenconnor.com or @AnneENConnor.
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\n\n","field_banner_alt":"Photograph of a volcanic vent on the ocean floor. Colored minerals can be seen on the rock, as well as plumes of white smoke.","field_banner_title":"White smoker","field_caption":"
Deep-sea hot-spring vents, like these on the underwater Kawio Barat volcano in Indonesia, are a leading candidate for where life may have originated on the early Earth around 4 billion years ago. Such vents contain many of the needed ingredients, including key minerals (the whitish “smoke” rising from the vent) and electrical currents.
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CREDIT: NOAA OKEANOS EXPLORER PROGRAM / SCIENCE SOURCE
","field_doi":"10.1146/knowable-072120-1","field_is_hero":"1","metatags":{"referrer":"origin","title":"Searching high and low for the origins of life","description":"Researchers think they’re getting warmer: They’ve created amino acids and primitive membranes by simulating conditions found at scalding vents on the ocean floor","google_plus_name":"Searching high and low for the origins of life","og_title":"Searching high and low for the origins of life","og_site_name":"Knowable Magazine | Annual Reviews","og_type":"article","twitter_cards_type":"summary_large_image","canonical_url":"/article/physical-world/2020/searching-high-and-low-origins-life","dcterms_description":"Researchers think they’re getting warmer: They’ve created amino acids and primitive membranes by simulating conditions found at scalding vents on the ocean floor","dcterms_identifier":"10.1146/knowable-072120-1","dcterms_publisher":"Annual Reviews","dcterms_title":"Searching high and low for the origins of life","dcterms_type":"article","fb_admins":"1642929092406128","google_plus_description":"Researchers think they’re getting warmer: They’ve created amino acids and primitive membranes by simulating conditions found at scalding vents on the ocean floor","google_plus_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=-ecxrbeI","citation_author":"","citation_journal_title":"Knowable Magazine | Annual Reviews","citation_publication_date":"Tuesday, July 21, 2020 - 08:00","citation_title":"Searching high and low for the origins of life","article_modified_time":"Tuesday, July 21, 2020 - 16:18","article_published_time":"Tuesday, July 21, 2020 - 08:00","og_description":"Researchers think they’re getting warmer: They’ve created amino acids and primitive membranes by simulating conditions found at scalding vents on the ocean floor","og_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=-ecxrbeI","og_image_height":"600","og_image_type":"image/jpeg","og_image_url":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=-ecxrbeI","og_image_width":"1600","og_updated_time":"Tuesday, July 21, 2020 - 16:18","og_url":"/article/physical-world/2020/searching-high-and-low-origins-life","twitter_cards_description":"Researchers think they’re getting warmer: They’ve created amino acids and primitive membranes by simulating conditions found at scalding vents on the ocean floor","twitter_cards_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/506/hydrothermal-vents-1600x600.jpg?itok=-ecxrbeI","twitter_cards_image_height":"600","twitter_cards_image_width":"1600","twitter_cards_page_url":"/article/physical-world/2020/searching-high-and-low-origins-life","twitter_cards_site":"@knowablemag","twitter_cards_title":"Searching high and low for the origins of life","dc_identifier":"10.1146/knowable-072120-1","pocket-site-verification":"665d7e2e5dc1fa27727a154d5c4e80"},"field_primary_author":"By Anne N. Connor","field_published":"2020-07-21","field_republish_html":"

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Searching high and low for the origins of life
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Researchers think they’re getting warmer: They’ve created amino acids and primitive membranes by simulating conditions found at scalding vents on the ocean floor
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By Anne N. Connor
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7.21.2020
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Hot, bubbling fissures in the deep, sunless ocean seem unlikely places for life at all, let alone life’s origin. Yet recent studies have shown that two essential ingredients — amino acids and primitive cell membranes — can form spontaneously and reliably near the hydrothermal vents found in seafloors. The discoveries bolster a hypothesis about life’s origins that some scientists have supported for decades.
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Hydrothermal vents are chemical hot springs near fault lines on the ocean floor. Some, called white smokers, have elaborate mineral pillars or chimneys that are full of tiny chambers in which chemical reactions can take place. At 158 degrees Fahrenheit (70 degrees Celsius), the vents are a bit hot for a bubble bath but, it turns out, just right for the formation of amino acids and structures that could serve as cell membranes.
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Scientists suspect that deep hot vents like these might have seeded life on Earth about 4 billion years ago. Some hydrothermal vents release alkaline fluids, which could supply the energy needed to build complex organic molecules. And the basic chemistry of life “appears to match what you might expect if life began in this hot, dark, chemical-energy-powered setting,” says earth system scientist Timothy Lenton of the UK’s University of Exeter, a coauthor of a 2017 article on ocean biogeochemistry in the Annual Review of Marine Science.
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The vent hypothesis is somewhat controversial, but recent experiments lend weight to it. In one, NASA astrobiologist Laurie Barge and her colleagues showed how amino acids, the building blocks of proteins, could have formed near alkaline vents. Barge, of the Jet Propulsion Laboratory in Pasadena, California, became interested in the origin of life on Earth while searching for life not on Earth. Geology and biology would be closely linked anywhere, she says — whether on another planet or in a deep-sea vent here on Earth.
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To learn whether life’s building blocks could have formed near ancient vents, Barge’s team created miniature vents in the laboratory. Their simulated ocean water contained ammonia, the simple organic molecule pyruvate and iron hydroxide minerals, all of which likely existed in Earth’s early oceans. The water was depleted of oxygen and adjusted to 158 degrees F, the temperature of white smokers. Within these simulated vents, the chemical conditions allowed electrons to flow between the iron minerals and pyruvate, yielding the amino acid alanine, the team reported last year in the Proceedings of the National Academy of Sciences.
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The researchers could regulate the amount of alanine produced by adjusting the ratios of different iron hydroxide minerals to control how many electrons the iron released — like “a dial that could be tuned up or down,” Barge says. Electrons flow continuously from alkaline vents, providing a constant source to trigger chemical reactions.
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Creating life’s building blocks
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Amino acids are important, but life is organized in cells — and cells can’t operate without a cell membrane. In the second experiment, biochemist Nick Lane at University College London and his colleagues showed how primitive membranes could form near alkaline vents.
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Lane used a laboratory replica of ancient deep-sea conditions to determine whether lipid-surrounded bubbles called vesicles — a sort of protocell — could form there. His team added 14 fatty acids and other chemicals, which would likely have been present in the early ocean, to acidic, simulated seawater. The scientists adjusted the liquid to be alkaline, making the chemicals go into solution. When the researchers slowly mixed the solution with seawater, the fatty acids assembled into vesicles. Vesicles formed most readily in conditions strikingly like white smokers — at 158 degrees F with strong alkalinity, the scientists reported in November in Nature Ecology & Evolution.
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Earlier studies had failed to form vesicles in hot, alkaline salt water — but that’s because they used fewer types of fatty acids, says Sean Jordan, a biogeochemist at University College London and a coauthor of the paper. His team used a large variety of them, which provided more ways for them to bond with one another.
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Some scientists aren’t convinced that life originated at a deep, alkaline hydrothermal vent. David Deamer, a biophysicist at the University of California, Santa Cruz, is one of several who say that salty ocean water would destroy the fatty acids needed to create cell membranes. He has shown that vesicles can form in freshwater — no deep-sea vents needed — by wetting and drying fatty acids. He offers the example of blowing soap bubbles. Soap is disordered in a solution with water, but blow a puff of air into it and the molecules assemble themselves into a membrane.
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Imagine a freshwater hot spring, where the surrounding ground gets damp after a rain and then periodically dries out. As things dry up, the compounds dissolved in the water become more concentrated. When drying removes water molecules, energy is released, creating the bonds that allow complex organic molecules to form.
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Another point in favor of the freshwater model is the origin of the first self-replicating molecules, Deamer says. Organisms must have a way to pass down information to the next generation if they are to reproduce; many scientists think that RNA was the first molecule capable of this. Years ago, Deamer and his colleagues created complex molecules that functioned like RNA by wetting and drying simple organic molecules in shallow freshwater pools. The drying process organized molecules to be more complex, without requiring an external jolt of energy.
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The story isn’t so simple, though. Both research camps have struggled to show that the basic biological molecules they make in the lab would actually function inside living organisms. Still, the hydrothermal vent proponents say they have all the right ingredients — including the energy needed to kickstart life. White smokers can supply energy in two ways, and one or both could have provided the power needed to build complex organic molecules.
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The first happens when alkaline fluids spurt out of the seafloor and collide with acidic ocean water. This pH gradient creates a minor electric charge across the vent chimney. (In another study, Barge lit a small LED by linking hydrothermal chimneys together with wires.) Earth’s early oceans were more acidic than today, suggesting there could have been plenty of energy available at deep-sea vents.
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The other way that alkaline vents supply energy is by feeding a process in which electrons flow between chemicals in the ocean and rocks. This underwater electrical current could have driven the first life-giving chemical reactions. “Electricity is necessary to the origin of life,” says Lars Peter Nielsen, an electromicrobiologist at Aarhus University in Denmark. “Electricity makes it all come together.”
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Perhaps the most convincing argument for a marine origin of life is timing. Studies that track how life forms have evolved suggest that the earliest life on Earth emerged about 4 billion years ago. That timeline means life almost certainly originated in the ocean, Lenton says. The first continents hadn’t formed 4 billion years ago, so the surface of the planet was almost entirely ocean.
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Explore Knowable’s coronavirus coverage
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Some of the oldest evidence for life on Earth comes from ancient chemical signatures and fossils in sedimentary rocks in Canada, which likely formed on the ocean floor. One study, reported in 2017 in Nature, even found tube-like fossils that look like microorganisms living near hydrothermal vents today — but in rocks that are at least 3.77 billion years old.
\n\n
Deamer argues that there would have been some landmasses 3.5 billion to 4 billion years ago, with the flanks of volcanoes emerging from the water. And freshwater pools could have formed on those landmasses through rainfall. If that’s plausible, says Deamer, so is a freshwater origin of life on Earth.
\n\n
Whether life originated in the deep ocean or shallow terrestrial pools remains to be seen. But it now seems likely that crucial organic molecules, and the membranes to hold them, could have been generated using the geochemistry of early Earth.
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10.1146/knowable-072120-1
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Anne N. Connor is a science writer newly relocated to Vermont. Reach her at https://annenconnor.com or @AnneENConnor.
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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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$\"Knowable$
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On some worlds, the sun never sets. Or rises. If a planet takes the same amount of time to spin once about its axis as it does to orbit once about its parent star, that star will appear to hang motionless in the sky. Such planets show only one face to their star, a situation known as tidal locking.
A tidally locked planet is a bifurcated world. On one side it’s always day; on the other, eternal night. The boundary between features a thin ring of twilit eternity, where the sun is forever setting (or rising, if you prefer). A number of worlds in our own solar system are tidally locked — including our moon — and any number of exoplanets that orbit their own stars in other solar systems may be tidally locked as well.
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When gravitational forces slow or accelerate the rotation of an astronomical body it can become tidally locked to its parent body (in this example, a planet is tidally locked to its star). Under these conditions the orbiting body always shows the same face to its parent body. Our moon is tidally locked to Earth and scientists suspect that many exoplanets orbiting relatively close to their stars may also be tidally locked.
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Many of these planets will be inhospitable, baked on one side and frozen on the other. Yet astronomers have long contemplated whether such worlds might harbor life, as have sci-fi enthusiasts. Now sophisticated computer modeling and new data are illuminating more about the atmospheres of these tidally locked, distant worlds. The research is adding weight to the notion that some may not be so hostile.
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“There’s nothing really especially bad about tidal locking,” says physicist Raymond Pierrehumbert of the University of Oxford in England. “The day side is perfectly good habitat and there’s quite a lot of it.”
Slowing the spin
For a nearby example of tidal locking we need only look up: Our moon is tidally locked to the Earth, the result of a gradual slowing of the moon’s rotation over millions of years due to gravitational interactions with our planet. Just as the moon’s gravity sloshes our oceans back and forth to create tides (hence “tidal locking”), a star’s gravity pulls on the rocky body of an orbiting planet, creating a bulge.
If a planet is rotating either faster or slower than the pace at which it orbits its star, that bulge will be slightly off-center. Over time, the tug of the star’s gravity on the misaligned bulge will gradually slow or boost a planet’s spin until they reach an equilibrium: The planet will rotate on its axis exactly once for every time it circles its star.
The effect is most pronounced on worlds that are very close to their orbital companions, which is why the moon is tidally locked to the Earth, but the Earth isn’t tidally locked to the sun.
Pluto and its moon Charon also show only one face to each other — they orbit so closely and are similar enough in size that tidal forces synced both of their rotations.
While astronomers don’t have an exact count of the number of tidally locked worlds, it’s “a basic expectation” that many exoplanets are gravitationally bound to their stars in this way, says planetary scientist Daniel Koll of MIT.
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Pluto and its moon Charon, depicted here from a side view, are tidally locked to each other. Typically, an orbiting body is tidally locked to a larger body, but Pluto and Charon are similar enough in size and close enough in distance that each is tidally locked to the other.
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CREDIT: TOMRUEN / WIKIMEDIA COMMONS
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Many of these bodies will be places of extremes, at once both roasted and frozen. Consider a large rocky exoplanet called 55 Cancri e, which orbits its sunlike G-type star about once every 18 hours.
“It’s so hot you have a permanent magma ocean on the day side,” says Pierrehumbert, who describes the atmospheres of tidally locked worlds in a recent Annual Review of Fluid Dynamics. “And then you get rock vapor that evaporates into the atmosphere and then condenses out toward the nightside. So you have rain made out of silicon monoxide and things like that.”
But a tidally locked planet with an atmosphere something like Earth’s might redistribute heat fairly efficiently, says Koll. The result could be environments amenable to life — a longtime goal of planet hunters.
Air and water
Around the turn of the last century, astronomers erroneously thought that Venus might be tidally locked. “Between the two separate regions of perpetual night and day there must lie a wide zone of subdued rose-flushed twilight, where the climatic conditions may be well suited to the existence of a race of intelligent beings,” wrote E.V. Heward in 1903.
Optimism regarding the habitability of the “twilight zone” also emerged in the world of science fiction, says University of Chicago geophysicist Dorian Abbot. The idea was that the region between the planet’s light and dark side would be mild enough for water to exist in liquid form and perhaps allow life to survive.
Research has cast doubt on that theory. The twilight zone — which astronomers call the “terminator” — would be a poor place for organisms that need the sun’s light to survive.
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Twilight, the gradual transition from day to night, shown here from above Earth, has captured people’s imagination as a place that might support life on exoplanets. But a twilight zone, or the terminator in astronomy parlance, may not be the only habitable portion of an exoplanet if it has a suitable atmosphere.
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CREDIT: ISS EXPEDITION 2 CREW / GATEWAY TO ASTRONAUT PHOTOGRAPHY OF EARTH / NASA
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But you don’t need a twilight zone to support life if you have the right atmosphere, says Abbot.
An atmosphere transports heat around the planet, making conditions that could support liquid water — and perhaps life — more widespread. “It wouldn't just be at the terminator,” Abbot says, “it would be all over the place.”
There’s a balancing act: The atmosphere needs to be dense enough to transport heat, but not so dense as to become smothering. Conversely, if the nightside becomes too cold, it could freeze the gases out, stealing an atmosphere entirely.
A 2016 simulation developed by Abbot and Koll indicates that the right balance is achievable: Some tidally locked exoplanets could host “just right” atmospheres that move heat around efficiently enough to keep even the night side warm.
“It would be strange because it would be permanently night but you might still have conditions where life similar to ours could exist,” says Koll. Consider the poles on Earth, where life persists, even though sunlight is scarce. “It doesn’t get too deadly cold, in great part because wind or motions of the ocean actually redistribute heat.”
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On Earth, oceans are key players in the global circulation of heat; water holds more heat energy than air and is far more efficient at moving that heat around. So, along with an atmosphere, oceans could play an important role in keeping the day and night sides of a tidally locked exoplanet temperate.
Oceans also lead to evaporation, spurring the formation of clouds that can also play an important role in regulating conditions on a planet, says Feng Ding, a researcher at Harvard studying exoplanet atmospheres. Clouds that form as water collects in the atmosphere can serve as a kind of reflective blanket, bouncing incoming stellar radiation back out and helping to cool a planet.
Some computer simulations suggest that clouds could keep temperatures low enough for oceans to form even on exoplanets that might otherwise be boiling hot. And those clouds would create rain. On the planet’s day side, strong updrafts created where sunlight is most intense would move warm, wet air upwards, creating torrential rainstorms, says Pierrehumbert.
Land and life?
That rain could help regulate a tidally locked exoplanet’s temperature, especially if there’s also land. On Earth, rain reacts with exposed rock, trapping some carbon as a mineral and removing it from the atmosphere, which helps cool the planet. Over time, this chemical weathering could also keep carbon dioxide levels manageable on a tidally locked planet, Pierrehumbert says.
Other atmospheric gases could also make an exoplanet more hospitable, he speculates. Nitrogen, for example, helps prevent water loss by trapping it lower in the atmosphere, where it’s exposed to fewer ultraviolet rays that break water vapor apart into oxygen and hydrogen. A nitrogen-laden atmosphere would help maintain the liquid oceans that serve as key regulators of temperature.
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This lighthearted NASA space tourism poster features the exoplanets orbiting the red dwarf star TRAPPIST-1. Each of the seven planets that orbit the dim red dwarf star are thought to be tidally locked to the star. The tourists are taking in TRAPPIST-1e, which is in the star’s habitable zone, making it the most likely TRAPPIST-1 planet to support liquid water.
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CREDIT: NASA-JPL / CALTECH
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Scientists can feed many of these variables into computer simulations, but much of exoplanet atmospheric research is speculative. Studies of tidally locked bodies are no exception. For one thing, data that would ground-truth all these variables are scarce. And, says Koll, most exoplanet atmosphere astronomy has been confined to planets that don’t look much like Earth. They are much larger and are often covered by thick atmospheres, like Neptune and Uranus.
But new instruments, such as NASA’s Transiting Exoplanet Survey Satellite (TESS) will greatly expand the number of exoplanets that have been detected. And when NASA’s James Webb Space Telescope finally launches in 2021 — pending possible delays due to the coronavirus pandemic — it will allow for even more detailed observations of exoplanets, including data on the composition of their atmospheres.
Those data will help astronomers refine their models and better understand the conditions that could make any planet habitable — including far-off, tidally locked ones. With potentially trillions of exoplanets in existence, there might be one with shallow oceans where life could form, balmy continents where organisms grow or crawl and an atmosphere where they might take to the skies. There, under the eternal light of an ever-present alien sun, life could prosper.
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\n \n \n \n By\n\n \n Nathaniel Scharping\n \n \n \n \n 07.07.2020\n
\n","field_ar_article":{"arguments":[]},"field_author_bios":"
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Nathaniel Scharping is a science writer and editor from Milwaukee. All things considered, he doesn’t mind a bit of spin. Follow him on Twitter @NathanielScharp
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\n","field_banner_alt":"Artist’s rendering of a cold eyeball planet features a glowing orange “pupil” where the sun hits the planet, surrounded by dark blue ocean and then an icy white edge that recedes into darkness.","field_banner_title":"Locked exoplanet","field_caption":"
A tidally locked planet shows only one face to its star, with implications for its climate. In one scenario, the planet resembles a giant eyeball, as shown in this illustration. The cold eyeball planet has a liquid ocean on the light side, while an icy shell covers the dark side.
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CREDIT: NASA-JPL / CALTECH
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Beyond the twilight zone
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Tidally locked worlds are places of extremes. On one side it’s an endless day, the other a perpetual night. Yet scientists speculate that some may harbor conditions that could support life.
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\n By Nathaniel Scharping \n \n
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7.7.2020
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On some worlds, the sun never sets. Or rises. If a planet takes the same amount of time to spin once about its axis as it does to orbit once about its parent star, that star will appear to hang motionless in the sky. Such planets show only one face to their star, a situation known as tidal locking.
A tidally locked planet is a bifurcated world. On one side it’s always day; on the other, eternal night. The boundary between features a thin ring of twilit eternity, where the sun is forever setting (or rising, if you prefer). A number of worlds in our own solar system are tidally locked — including our moon — and any number of exoplanets that orbit their own stars in other solar systems may be tidally locked as well.
Many of these planets will be inhospitable, baked on one side and frozen on the other. Yet astronomers have long contemplated whether such worlds might harbor life, as have sci-fi enthusiasts. Now sophisticated computer modeling and new data are illuminating more about the atmospheres of these tidally locked, distant worlds. The research is adding weight to the notion that some may not be so hostile.
“There’s nothing really especially bad about tidal locking,” says physicist Raymond Pierrehumbert of the University of Oxford in England. “The day side is perfectly good habitat and there’s quite a lot of it.”
Slowing the spin
For a nearby example of tidal locking we need only look up: Our moon is tidally locked to the Earth, the result of a gradual slowing of the moon’s rotation over millions of years due to gravitational interactions with our planet. Just as the moon’s gravity sloshes our oceans back and forth to create tides (hence “tidal locking”), a star’s gravity pulls on the rocky body of an orbiting planet, creating a bulge.
If a planet is rotating either faster or slower than the pace at which it orbits its star, that bulge will be slightly off-center. Over time, the tug of the star’s gravity on the misaligned bulge will gradually slow or boost a planet’s spin until they reach an equilibrium: The planet will rotate on its axis exactly once for every time it circles its star.
The effect is most pronounced on worlds that are very close to their orbital companions, which is why the moon is tidally locked to the Earth, but the Earth isn’t tidally locked to the sun.
Pluto and its moon Charon also show only one face to each other — they orbit so closely and are similar enough in size that tidal forces synced both of their rotations.
While astronomers don’t have an exact count of the number of tidally locked worlds, it’s “a basic expectation” that many exoplanets are gravitationally bound to their stars in this way, says planetary scientist Daniel Koll of MIT.
Many of these bodies will be places of extremes, at once both roasted and frozen. Consider a large rocky exoplanet called 55 Cancri e, which orbits its sunlike G-type star about once every 18 hours.
“It’s so hot you have a permanent magma ocean on the day side,” says Pierrehumbert, who describes the atmospheres of tidally locked worlds in a recent Annual Review of Fluid Dynamics. “And then you get rock vapor that evaporates into the atmosphere and then condenses out toward the nightside. So you have rain made out of silicon monoxide and things like that.”
But a tidally locked planet with an atmosphere something like Earth’s might redistribute heat fairly efficiently, says Koll. The result could be environments amenable to life — a longtime goal of planet hunters.
Air and water
Around the turn of the last century, astronomers erroneously thought that Venus might be tidally locked. “Between the two separate regions of perpetual night and day there must lie a wide zone of subdued rose-flushed twilight, where the climatic conditions may be well suited to the existence of a race of intelligent beings,” wrote E.V. Heward in 1903.
Optimism regarding the habitability of the “twilight zone” also emerged in the world of science fiction, says University of Chicago geophysicist Dorian Abbot. The idea was that the region between the planet’s light and dark side would be mild enough for water to exist in liquid form and perhaps allow life to survive.
Research has cast doubt on that theory. The twilight zone — which astronomers call the “terminator” — would be a poor place for organisms that need the sun’s light to survive.
But you don’t need a twilight zone to support life if you have the right atmosphere, says Abbot.
An atmosphere transports heat around the planet, making conditions that could support liquid water — and perhaps life — more widespread. “It wouldn't just be at the terminator,” Abbot says, “it would be all over the place.”
There’s a balancing act: The atmosphere needs to be dense enough to transport heat, but not so dense as to become smothering. Conversely, if the nightside becomes too cold, it could freeze the gases out, stealing an atmosphere entirely.
A 2016 simulation developed by Abbot and Koll indicates that the right balance is achievable: Some tidally locked exoplanets could host “just right” atmospheres that move heat around efficiently enough to keep even the night side warm.
“It would be strange because it would be permanently night but you might still have conditions where life similar to ours could exist,” says Koll. Consider the poles on Earth, where life persists, even though sunlight is scarce. “It doesn’t get too deadly cold, in great part because wind or motions of the ocean actually redistribute heat.”
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On Earth, oceans are key players in the global circulation of heat; water holds more heat energy than air and is far more efficient at moving that heat around. So, along with an atmosphere, oceans could play an important role in keeping the day and night sides of a tidally locked exoplanet temperate.
Oceans also lead to evaporation, spurring the formation of clouds that can also play an important role in regulating conditions on a planet, says Feng Ding, a researcher at Harvard studying exoplanet atmospheres. Clouds that form as water collects in the atmosphere can serve as a kind of reflective blanket, bouncing incoming stellar radiation back out and helping to cool a planet.
Some computer simulations suggest that clouds could keep temperatures low enough for oceans to form even on exoplanets that might otherwise be boiling hot. And those clouds would create rain. On the planet’s day side, strong updrafts created where sunlight is most intense would move warm, wet air upwards, creating torrential rainstorms, says Pierrehumbert.
Land and life?
That rain could help regulate a tidally locked exoplanet’s temperature, especially if there’s also land. On Earth, rain reacts with exposed rock, trapping some carbon as a mineral and removing it from the atmosphere, which helps cool the planet. Over time, this chemical weathering could also keep carbon dioxide levels manageable on a tidally locked planet, Pierrehumbert says.
Other atmospheric gases could also make an exoplanet more hospitable, he speculates. Nitrogen, for example, helps prevent water loss by trapping it lower in the atmosphere, where it’s exposed to fewer ultraviolet rays that break water vapor apart into oxygen and hydrogen. A nitrogen-laden atmosphere would help maintain the liquid oceans that serve as key regulators of temperature.
Scientists can feed many of these variables into computer simulations, but much of exoplanet atmospheric research is speculative. Studies of tidally locked bodies are no exception. For one thing, data that would ground-truth all these variables are scarce. And, says Koll, most exoplanet atmosphere astronomy has been confined to planets that don’t look much like Earth. They are much larger and are often covered by thick atmospheres, like Neptune and Uranus.
But new instruments, such as NASA’s Transiting Exoplanet Survey Satellite (TESS) will greatly expand the number of exoplanets that have been detected. And when NASA’s James Webb Space Telescope finally launches in 2021 — pending possible delays due to the coronavirus pandemic — it will allow for even more detailed observations of exoplanets, including data on the composition of their atmospheres.
Those data will help astronomers refine their models and better understand the conditions that could make any planet habitable — including far-off, tidally locked ones. With potentially trillions of exoplanets in existence, there might be one with shallow oceans where life could form, balmy continents where organisms grow or crawl and an atmosphere where they might take to the skies. There, under the eternal light of an ever-present alien sun, life could prosper.
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10.1146/knowable-070620-1
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Nathaniel Scharping is a science writer and editor from Milwaukee. All things considered, he doesn’t mind a bit of spin. Follow him on Twitter @NathanielScharp
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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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It was the muddy water that caught Stefan Talke’s eye.
In the mid-2000s Talke was a postdoctoral scholar at Utrecht University, studying the Ems River that empties into the North Sea between Germany and the Netherlands. Decades earlier, engineers had begun dredging parts of the Ems so that newly built ships could navigate it from a shipyard upriver.
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But those changes also changed the rhythm in which tides ebbed and flowed into the river from the sea. Those shifting tides stirred up sediment from the river bottom and muddied its waters. Over the last 120 years the tidal range — the distance between high and low tide — has quintupled in the Ems estuary.
“I had always assumed tides were constant,” says Talke, now an oceanographer at California Polytechnic State University in San Luis Obispo. “That’s why we have tide tables.” He was amazed to discover, he says, that not only could tides undergo long-term changes, but that they could change by so much.
Most people think of tides as regular and predictable — the rise and fall of coastal waters, caused by the gravitational tug of the moon and the sun, forecast down to the minute with a mariner’s tide table. But oceanographers have recently started to realize that tides in many places around the world are undergoing notable changes, in ways that can’t be explained by interactions among celestial bodies.
Rather, people are causing these changing tides. Dredging river channels like the Ems or filling in coastal wetlands can trigger shifts. The nature of those shifts is complicated: In some locations the tidal range grows more dramatic, whereas in others it shrinks. Either way, the shifting tides have big implications for hundreds of millions of coastal residents.
Perhaps the biggest challenge is how changing tides might add to the risks of sea level rise. As people burn more fossil fuels and put more heat-trapping greenhouse gases into the atmosphere, global warming is melting ice caps and causing the volume of the oceans to expand. In many coastal cities, seawater is now lapping higher than it ever has. Changing tides could add to that problem and leave some coasts at even greater risk of flooding. “What people don’t realize is that if tidal range is increasing, it will exacerbate that even more,” says Ivan Haigh, an oceanographer at the University of Southampton, UK.
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The tidal range along the Thames River has quadrupled since the time of the Romans, as engineers narrowed and deepened the river for navigation. Those tides rhythmically submerged and revealed the Rising Tide sculpture, underwater artist Jason deCaires Taylor’s 2015 installation at Vauxhall in London.
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CREDIT: THAMES FESTIVAL TRUST
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Tides of history
Engineers have known for at least a century that tides can change locally. In 1899, builders predicted that tides would increase in the Ems River upstream from a weir they planned to construct. (After the weir was built, the tides did increase about as much as they were expecting.) But only recently have scientists collected modern, precise tide gauge data from around the world, showing just how widespread tidal changes have become. “It wasn’t really until about 10 years ago that we started to appreciate that it’s occurring on a much wider level,” says Haigh.
Tides come in several flavors, all ultimately tracing back to interactions between the moon, the sun and Earth. Each tidal cycle causes coastal waters to rise and fall in a predictable pattern, dictated by the orbits of these bodies.
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As Earth spins, the moon's gravity exerts forces of slightly different direction and magnitude on each point of the planet's surface. Ocean water responds by flowing and generating tidal bulges on opposite sides of the planet. High tides occur approximately twice each lunar day, which lasts 24 hours and 50 minutes, as Earth rotates through these bulges. Low tides occur in between.
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SOURCE: NATIONAL OCEAN SERVICE / CREDIT: KNOWABLE MAGAZINE
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Twice a month, when the sun, the moon and Earth are nearly in alignment, Earth experiences “spring” tides. During these periods high tides are a little higher than usual and low tides are a little lower than usual. Seven days after spring tides, when the sun and the moon are at right angles to each other, their gravitational tugs partly cancel each other out, resulting in moderate “neap” tides.
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SOURCE: NATIONAL OCEAN SERVICE / CREDIT: KNOWABLE MAGAZINE
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The gravitational tugs of the moon and the sun don’t change over the short term. But what does change is the way the Earth’s waters respond to that tugging. Think of tides as repeating waves that bounce off landmasses and slosh upriver — sometimes traveling hundreds of kilometers inland, as they do in South America’s Amazon River, where surfers ride the tidal waves. If you change the geometry of the land they slosh around in, you change the tides, says Talke. “It’s like having a different size or shape of a tub or a swimming pool — you’d expect water to flow differently in it,” he says.
In that sense, it’s not terribly surprising that tides have changed dramatically in places where people have changed the shape of the underwater landscape. Along the Cape Fear River in North Carolina, dredging to deepen a ship channel has caused the tidal range in the city of Wilmington to double, to 1.55 meters (5.1 feet), since the 1880s. The same is true for Jacksonville, Florida, which sits alongside the dredged St. Johns River.
In Sacramento, California, tides disappeared in the late 1800s after mining from the Gold Rush sent silt rushing downstream; later dredging of the Sacramento River brought the tides back. And in the Thames estuary that runs through London, engineers have narrowed and deepened the river over centuries; its tidal range has increased from around 2 meters (6.6 feet) in the time of the Romans to around 8 meters (26.2 feet) in the Victorian age.
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Tidal changes also happen whenever flowing water generates more or less turbulent energy as it moves through the landscape, write Talke and David Jay, an oceanographer at Portland State University in Oregon, in the recent Annual Review of Marine Science. Stripping away underwater plants reduces drag and lets waters flow more freely, potentially allowing tides to increase. Adding dikes or piers causes water to flow more turbulently and dissipate its energy faster, likely dampening tides.
Water depth is another important factor in tidal changes, says Haigh. Because tides propagate as shallow-water waves, they change the most wherever the water is also shallow. That’s why the Bay of Fundy, between New Brunswick and Nova Scotia in Canada, has some of the most dramatic tidal ranges in the world, with waters rising and falling more than 11 meters (36 feet) each day. Shallow spots like this are likely to see large changes in tidal range as sea levels rise, Haigh says. “The way the water moves across the basin is changing, which is having quite a profound effect on the tides,” he says.
Planning for high tides, floods and surges
Changing tides affect coastal residents in many ways. Someone who wants to sail a tall ship under a short bridge has to wait for just the right tidal conditions. Someone who wants to build a riverfront home in an estuary has to know exactly where the high-tide mark is. Someone designing a tidal-energy system needs to know how much energy they can extract from the water flows. And that’s where the study of changing tides can help people prepare for a changing world, Talke says.
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The Bay of Fundy, between New Brunswick and Nova Scotia in Canada, experiences the world’s most extreme tides, with waters rising and falling more than 11 meters (36 feet).
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CREDIT: NOVA SCOTIA WEBCAMS
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Perhaps most importantly, engineers can analyze changing tides to better plan for future sea level rise. One recent study looked at the low-lying Pearl River Delta in southern China, which is home to more than 60 million people. Michela De Dominicis, an oceanographer at the National Oceanography Centre in Liverpool, UK, and her colleagues calculated how much tidal ranges would shift for a variety of future scenarios of sea level rise.
If sea level were to rise between 0.5 and 2.1 meters (1.6 and 6.9 feet) in the delta, then cities in its upstream reaches would see tidal increases between 0.1 and 0.5 meters (0.3 and 1.6 feet), the scientists reported in February in Geophysical Research Letters. Add those numbers together and it looks as if water levels could go up between 0.6 and 2.6 meters (2 and 8.5 feet).
Several cities in the delta, including Guangzhou and Shenzhen, are among the world’s most vulnerable to rising water levels, says De Dominicis. Knowing how high the water levels could rise can help planners build better barriers and other coastal defenses.
Researchers are also using computer models to analyze how changing tides and rising sea levels might affect other types of coastal flooding. A hurricane’s storm surge, for instance, often responds to the changing landscape much as tides do. In a 2016 study, Talke and Ramin Familkhalili of Portland State analyzed how storm surge might change in the Cape Fear River estuary along with the changing tides.
The researchers calculated that dredging of the ship channel has effectively worsened the potential damage posed by a Category 5 hurricane and raised the highest possible water levels in Wilmington by 1.8 meters (5.9 feet). And in 2018, when Category 1 Hurricane Florence slammed into Wilmington, water levels did indeed reach a record 1.1 meters (3.6 feet) above high tide.
That’s why understanding changing tides is crucial to preparing for the future, Talke says. People are going to continue to dredge channels and fill in wetlands and otherwise alter our coastal surroundings. Bit by bit, each modification shifts the world in which we live. “The sum of all the little changes,” Talke says, “turns out to be a really big change.”
Editor’s note: This article was updated on April 22, 2020, to rephrase the description of the weir built on the Ems River and to clarify the forces that contribute to high tides.\n
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\n \n \n \n By\n\n \n Alexandra Witze\n \n \n \n \n 04.22.2020\n
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Alexandra Witze (@alexwitze) is a science journalist in landlocked Boulder, Colorado.
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\n","field_banner_alt":"Photo of the Rising Tide sculpture by artist Jason deCaires Taylor installed within the tidal range on the Thames River in 2015; the sculpture was composed of four large, cement-gray horses with riders, the river’s high tide submerges the horses’ flanks.","field_banner_title":"Rising Tide sculpture","field_caption":"
As the tide rises and falls on the Thames in London, artist Jason deCaires Taylor’s 2015 Rising Tide installation dramatically reveals the river’s ebb and flow.
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CREDIT: PA IMAGES / ALAMY STOCK PHOTO
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The tides they are a-changin’ — and it’s not just from climate change
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Dredging rivers, filling in wetlands and other human acts of engineering have shifted coastal ebbs and flows worldwide. Add rising sea levels, and the threat of storm surges and floods will worsen in some places.
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\n By Alexandra Witze \n \n
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4.22.2020
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It was the muddy water that caught Stefan Talke’s eye.
In the mid-2000s Talke was a postdoctoral scholar at Utrecht University, studying the Ems River that empties into the North Sea between Germany and the Netherlands. Decades earlier, engineers had begun dredging parts of the Ems so that newly built ships could navigate it from a shipyard upriver.
But those changes also changed the rhythm in which tides ebbed and flowed into the river from the sea. Those shifting tides stirred up sediment from the river bottom and muddied its waters. Over the last 120 years the tidal range — the distance between high and low tide — has quintupled in the Ems estuary.
“I had always assumed tides were constant,” says Talke, now an oceanographer at California Polytechnic State University in San Luis Obispo. “That’s why we have tide tables.” He was amazed to discover, he says, that not only could tides undergo long-term changes, but that they could change by so much.
Most people think of tides as regular and predictable — the rise and fall of coastal waters, caused by the gravitational tug of the moon and the sun, forecast down to the minute with a mariner’s tide table. But oceanographers have recently started to realize that tides in many places around the world are undergoing notable changes, in ways that can’t be explained by interactions among celestial bodies.
Rather, people are causing these changing tides. Dredging river channels like the Ems or filling in coastal wetlands can trigger shifts. The nature of those shifts is complicated: In some locations the tidal range grows more dramatic, whereas in others it shrinks. Either way, the shifting tides have big implications for hundreds of millions of coastal residents.
Perhaps the biggest challenge is how changing tides might add to the risks of sea level rise. As people burn more fossil fuels and put more heat-trapping greenhouse gases into the atmosphere, global warming is melting ice caps and causing the volume of the oceans to expand. In many coastal cities, seawater is now lapping higher than it ever has. Changing tides could add to that problem and leave some coasts at even greater risk of flooding. “What people don’t realize is that if tidal range is increasing, it will exacerbate that even more,” says Ivan Haigh, an oceanographer at the University of Southampton, UK.
Tides of history
Engineers have known for at least a century that tides can change locally. In 1899, builders predicted that tides would increase in the Ems River upstream from a weir they planned to construct. (After the weir was built, the tides did increase about as much as they were expecting.) But only recently have scientists collected modern, precise tide gauge data from around the world, showing just how widespread tidal changes have become. “It wasn’t really until about 10 years ago that we started to appreciate that it’s occurring on a much wider level,” says Haigh.
Tides come in several flavors, all ultimately tracing back to interactions between the moon, the sun and Earth. Each tidal cycle causes coastal waters to rise and fall in a predictable pattern, dictated by the orbits of these bodies.
The gravitational tugs of the moon and the sun don’t change over the short term. But what does change is the way the Earth’s waters respond to that tugging. Think of tides as repeating waves that bounce off landmasses and slosh upriver — sometimes traveling hundreds of kilometers inland, as they do in South America’s Amazon River, where surfers ride the tidal waves. If you change the geometry of the land they slosh around in, you change the tides, says Talke. “It’s like having a different size or shape of a tub or a swimming pool — you’d expect water to flow differently in it,” he says.
In that sense, it’s not terribly surprising that tides have changed dramatically in places where people have changed the shape of the underwater landscape. Along the Cape Fear River in North Carolina, dredging to deepen a ship channel has caused the tidal range in the city of Wilmington to double, to 1.55 meters (5.1 feet), since the 1880s. The same is true for Jacksonville, Florida, which sits alongside the dredged St. Johns River.
In Sacramento, California, tides disappeared in the late 1800s after mining from the Gold Rush sent silt rushing downstream; later dredging of the Sacramento River brought the tides back. And in the Thames estuary that runs through London, engineers have narrowed and deepened the river over centuries; its tidal range has increased from around 2 meters (6.6 feet) in the time of the Romans to around 8 meters (26.2 feet) in the Victorian age.
Tidal changes also happen whenever flowing water generates more or less turbulent energy as it moves through the landscape, write Talke and David Jay, an oceanographer at Portland State University in Oregon, in the recent Annual Review of Marine Science. Stripping away underwater plants reduces drag and lets waters flow more freely, potentially allowing tides to increase. Adding dikes or piers causes water to flow more turbulently and dissipate its energy faster, likely dampening tides.
Water depth is another important factor in tidal changes, says Haigh. Because tides propagate as shallow-water waves, they change the most wherever the water is also shallow. That’s why the Bay of Fundy, between New Brunswick and Nova Scotia in Canada, has some of the most dramatic tidal ranges in the world, with waters rising and falling more than 11 meters (36 feet) each day. Shallow spots like this are likely to see large changes in tidal range as sea levels rise, Haigh says. “The way the water moves across the basin is changing, which is having quite a profound effect on the tides,” he says.
Planning for high tides, floods and surges
Changing tides affect coastal residents in many ways. Someone who wants to sail a tall ship under a short bridge has to wait for just the right tidal conditions. Someone who wants to build a riverfront home in an estuary has to know exactly where the high-tide mark is. Someone designing a tidal-energy system needs to know how much energy they can extract from the water flows. And that’s where the study of changing tides can help people prepare for a changing world, Talke says.
Perhaps most importantly, engineers can analyze changing tides to better plan for future sea level rise. One recent study looked at the low-lying Pearl River Delta in southern China, which is home to more than 60 million people. Michela De Dominicis, an oceanographer at the National Oceanography Centre in Liverpool, UK, and her colleagues calculated how much tidal ranges would shift for a variety of future scenarios of sea level rise.
If sea level were to rise between 0.5 and 2.1 meters (1.6 and 6.9 feet) in the delta, then cities in its upstream reaches would see tidal increases between 0.1 and 0.5 meters (0.3 and 1.6 feet), the scientists reported in February in Geophysical Research Letters. Add those numbers together and it looks as if water levels could go up between 0.6 and 2.6 meters (2 and 8.5 feet).
Several cities in the delta, including Guangzhou and Shenzhen, are among the world’s most vulnerable to rising water levels, says De Dominicis. Knowing how high the water levels could rise can help planners build better barriers and other coastal defenses.
Researchers are also using computer models to analyze how changing tides and rising sea levels might affect other types of coastal flooding. A hurricane’s storm surge, for instance, often responds to the changing landscape much as tides do. In a 2016 study, Talke and Ramin Familkhalili of Portland State analyzed how storm surge might change in the Cape Fear River estuary along with the changing tides.
The researchers calculated that dredging of the ship channel has effectively worsened the potential damage posed by a Category 5 hurricane and raised the highest possible water levels in Wilmington by 1.8 meters (5.9 feet). And in 2018, when Category 1 Hurricane Florence slammed into Wilmington, water levels did indeed reach a record 1.1 meters (3.6 feet) above high tide.
That’s why understanding changing tides is crucial to preparing for the future, Talke says. People are going to continue to dredge channels and fill in wetlands and otherwise alter our coastal surroundings. Bit by bit, each modification shifts the world in which we live. “The sum of all the little changes,” Talke says, “turns out to be a really big change.”
Editor’s note: This article was updated on April 22, 2020, to rephrase the description of the weir built on the Ems River and to clarify the forces that contribute to high tides.
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10.1146/knowable-042120-1
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Alexandra Witze ( @alexwitze) is a science journalist in landlocked Boulder, Colorado.
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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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When groups of people who speak different languages come together, they sometimes inadvertently create a new one, combining bits of each into something everyone can use to communicate easily. Linguists call such impromptu tongues “contact languages” — and they can extend well beyond the pidgin and creole that many of us have heard of.
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The origin stories of these linguistic mash-ups vary. Some are peaceful, such as when groups meet for trade and need a lingua franca: Nigerian Pidgin English, for example, allows speakers of over 500 tongues to communicate. But others were born of tragedy and violence — like Haitian Creole, Gullah Geechee, Jamaican Creole and many others that arose from the Atlantic slave trade, when West African peoples combined several tongues with English, creating everyday languages often used among slaves.
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Today, many of these contact languages are lost. Only 200 or so remain — scores of which are at risk of extinction. Linguists and anthropologists who traditionally have focused on the fate of more formal languages are paying increased attention: studying them with greater intensity and working with indigenous groups, international agencies, independent nonprofits, academics and others to preserve them.
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From pidgins — forms of simplified speech — used for commerce to the more mature creoles that have developed from them, contact languages exist all over the world. Some are transitory; others have persisted for hundreds of years. Through time, some that began as contact languages evolved into more formalized ones, explains linguist Shelome Gooden of the University of Pittsburgh, who as a child spoke English at school but Jamaican Creole — a mix of English and West African languages — at home.
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Turkish, for example, is a fully formed language that evolved about 1,000 years ago from an amalgamation of existing Turkic languages, Arabic and Persian languages as well as Greek and Armenian. But Gooden says it shows signs of reduplication, a feature common in creole and pidgin languages wherein existing words in a language are used to create new words. In Jamaican Creole, for example, “laaf” means simply “laugh,” but “laaf-laaf” becomes “to laugh a lot.” In Turkish, not typically grouped with contact languages, the word “derin” means “deep,” while “derin derin” means “deeply.” Traces like this offer linguists hints about the origins of languages when other historical clues may be missing, Gooden says.
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There is a reason contact languages have traditionally commanded less respect, says Nala H. Lee, a linguist at the National University of Singapore who wrote an overview of the status of contact languages in the 2020 Annual Review of Linguistics. “They’ve been thought to be bastardized versions of component languages from which they have been derived,” she says. “People think of them as being less good or not real languages.” Sometimes derisively referred to as “kitchen languages,” they are spoken in informal settings and are unlikely to be written down or used in official matters such as in court documents.
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But they are well worth saving, Lee says. The tongues are part of a people’s cultural or ethnic identity and history: When they disappear, which they do at a disproportionate rate to mature languages, an entire tradition can die with them — the Gullah Geechee language, for example, has a unique culture that comes, along with the tongue, from descendants of the slave trade still living on the southern Atlantic Coast of the United States. Contact languages also are a trove for linguists studying how languages evolve and how our brains learn to speak them.
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In research published in 2018 in Language Documentation & Conservation, Lee surveyed 96 contact languages for endangerment. She scored them by the number of fluent speakers, the extent to which they are being passed to the next generation and how widely they’re used by those who still speak them. Some might still be used in day-to-day trade, while others may be used only at home or small group settings, for example.
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Lee says that there are probably a little more than 200 contact languages in the world, 154 of them pidgins or creoles. For her survey, she chose 96 prominent and well-understood examples. Of the 96, 10 had lost their last speaker within the last 50 years — becoming dormant, as linguists put it — and 11 were critically endangered, with less than 10 speakers and a low chance of transmission to the next generation. Five more were severely endangered, with between 10 and 99 speakers left.
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In all, Lee’s work suggests that up to 96 percent of contact languages are either endangered or recently dormant, having lost the last known speakers — compared with less than 50 percent of the roughly 7,100 total languages worldwide. That means the risk of a contact language disappearing is nearly double that for all languages.
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Many contact languages are now threatened, including a few on the precipice of extinction, a state termed “dormancy” in linguistics. This map shows the 11 most critically endangered contact languages and where they are spoken. Some, like Kodiak Russian Creole, have so few remaining speakers, and were used in such insular situations and places, that linguists don’t know them well. Others, like Michif, are geographically widespread in Northern America but are spoken only among elder members of a group — in this case, descendants of French settlers and First Nations people, most often Cree.
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This is sometimes due to ephemeral needs — the contact that gives rise to a language may not last very long. Lee points to Northern Territory Pidgin English, which came about through trades between British settlers in northern Australia and some Asian countries. “It quickly became obsolete when trading was halted after 11 years,” Lee says. In other cases, evidence points to deliberate efforts to suppress informal languages. Once the United States took over Hawaii, for example, it banned Hawaiian Pidgin (a combination of English and Hawaiian), as well as the indigenous Hawaiian language, from being used in schools starting in 1896.
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The fact that contact languages are not written, but passed down orally, means they can fade as younger generations move away to seek economic opportunity elsewhere, leaving traditions to elders. On the US Virgin Islands, English gradually became the language of choice and Negerhollands — a creole that originated around 1700 and combined Dutch, English, French, Spanish and African languages — became extinct in 1987.
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Attempts to preserve the endangered tongues can be challenge: Just as contact languages command less respect on the outside, the speakers themselves may be reluctant to view them as worth saving, Lee says.
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But efforts are afoot around the world. Among these, the Gullah Geechee Cultural Heritage Corridor Commission in South Carolina works to preserve the language of the Gullah people. The Sri Lanka Malay Association aims to maintain the language and traditions of this small ethnic group in Sri Lanka. The Creole Heritage Center and the Louisiana Folklife Center, both affiliated with the North State University of Louisiana, promote Louisiana Creole, which is based on French, some Spanish and native African languages used by enslaved people from the period when Louisiana was French-held territory.
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And in Canada, some who identify as Métis — the descendants of First Nations people (primarily Cree) and French fur traders — are working to preserve Michif, a contact language that arose among the Métis that combines Cree and French. It’s listed as critical by the Endangered Languages Project, which tracks at-risk languages including contact languages. There are an estimated 200 Michif speakers left in the world, though Lee estimates that the number of speakers fluent enough to pass on the language to subsequent generations is far lower.
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Michif is a contact language that combined elements of Cree and French to produce a new tongue that is spoken by the Métis people of Canada and the United States. Efforts are afoot to try to save the endangered language, which has various dialects, or regional varieties. This video, from the Louis Riel Institute and the Manitoba Metis Federation, includes background on Michif as well as demonstrations of it being spoken.
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CREDIT: MANITOBA METIS FEDERATION
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In the British Columbia area, the Michif Language Revitalization Circle was formed about two years ago and focuses on preserving Heritage Michif — one of four Michif dialects spoken in Canada and small pockets in the United States. “Luckily, in our group, three of us grew up exposed to our language,” says program coordinator Anita Barker, whose maternal grandfather was Cree and maternal grandmother was Métis. “We’re by no means speakers, but we at least heard it and could speak some when we were growing up.” The group is trying to create a written, phonetically read form of the language, working with Métis elders who still speak the language and members of the circle who had exposure to Michif growing up.
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Though many contact languages face endangerment, others go on to thrive. Gooden points to Nigerian Pidgin English. There are more than 500 languages spoken in Nigeria, and to facilitate cross-communication Nigerian Pidgin has become the universal, everyday tongue of the country.
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There have also been moves to legitimize contact languages. In 1987, the government of Haiti made Haitian Creole an official language alongside French. Similar efforts are currently underway in Jamaica.
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But then there are tongues like Baba Malay — a combination of Malay and Hokkien spoken by the Peranakan ethnic group in the Malaysian state of Malacca — that only older generations have held onto. That includes Lee’s own grandparents. As these languages diminish, so do the cultures that created them.
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By John Wenz 08.11.2020
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John Wenz is digital producer at Knowable Magazine.
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\n\n","field_banner_alt":"A scene from a street market in Lagos, Nigeria, the largest city in Africa. Several stalls selling produce are shown, as well as vendors and shoppers.","field_banner_title":"Lagos, Nigeria","field_caption":"
A scene from a market in Lagos, Nigeria. The largest city in Africa, Lagos serves as a major center of commerce, with people from more than 250 ethnic groups. More than 500 languages are spoken in Nigeria, so many opt to converse in Nigerian Pidgin English, which incorporates words from across the country into an informal tongue that serves as a lingua franca.
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CREDIT: KRISTIAN BUUS / ALAMY STOCK PHOTO
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The fragile state of contact languages
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These linguistic mash-ups are at high risk of extinction. The race to save them is a matter of time, with more at stake than words.
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By John Wenz
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8.11.2020
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When groups of people who speak different languages come together, they sometimes inadvertently create a new one, combining bits of each into something everyone can use to communicate easily. Linguists call such impromptu tongues “contact languages” — and they can extend well beyond the pidgin and creole that many of us have heard of.
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Explore Knowable’s coronavirus coverage
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The origin stories of these linguistic mash-ups vary. Some are peaceful, such as when groups meet for trade and need a lingua franca: Nigerian Pidgin English, for example, allows speakers of over 500 tongues to communicate. But others were born of tragedy and violence — like Haitian Creole, Gullah Geechee, Jamaican Creole and many others that arose from the Atlantic slave trade, when West African peoples combined several tongues with English, creating everyday languages often used among slaves.
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Today, many of these contact languages are lost. Only 200 or so remain — scores of which are at risk of extinction. Linguists and anthropologists who traditionally have focused on the fate of more formal languages are paying increased attention: studying them with greater intensity and working with indigenous groups, international agencies, independent nonprofits, academics and others to preserve them.
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From pidgins — forms of simplified speech — used for commerce to the more mature creoles that have developed from them, contact languages exist all over the world. Some are transitory; others have persisted for hundreds of years. Through time, some that began as contact languages evolved into more formalized ones, explains linguist Shelome Gooden of the University of Pittsburgh, who as a child spoke English at school but Jamaican Creole — a mix of English and West African languages — at home.
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Turkish, for example, is a fully formed language that evolved about 1,000 years ago from an amalgamation of existing Turkic languages, Arabic and Persian languages as well as Greek and Armenian. But Gooden says it shows signs of reduplication, a feature common in creole and pidgin languages wherein existing words in a language are used to create new words.In Jamaican Creole, for example, “laaf” means simply “laugh,” but “laaf-laaf” becomes “to laugh a lot.” In Turkish, not typically grouped with contact languages, the word “derin” means “deep,” while “derin derin” means “deeply.” Traces like this offer linguists hints about the origins of languages when other historical clues may be missing, Gooden says.
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There is a reason contact languages have traditionally commanded less respect, says Nala H. Lee, a linguist at the National University of Singapore who wrote an overview of the status of contact languages in the 2020 Annual Review of Linguistics. “They’ve been thought to be bastardized versions of component languages from which they have been derived,” she says. “People think of them as being less good or not real languages.” Sometimes derisively referred to as “kitchen languages,” they are spoken in informal settings and are unlikely to be written down or used in official matters such as in court documents.
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But they are well worth saving, Lee says. The tongues are part of a people’s cultural or ethnic identity and history: When they disappear, which they do at a disproportionate rate to mature languages, an entire tradition can die with them — the Gullah Geechee language, for example, has a unique culture that comes, along with the tongue, from descendants of the slave trade still living on the southern Atlantic Coast of the United States. Contact languages also are a trove for linguists studying how languages evolve and how our brains learn to speak them.
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In research published in 2018 in Language Documentation & Conservation, Lee surveyed 96 contact languages for endangerment. She scored them by the number of fluent speakers, the extent to which they are being passed to the next generation and how widely they’re used by those who still speak them. Some might still be used in day-to-day trade, while others may be used only at home or small group settings, for example.
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Lee says that there are probably a little more than 200 contact languages in the world, 154 of them pidgins or creoles. For her survey, she chose 96 prominent and well-understood examples. Of the 96, 10 had lost their last speaker within the last 50 years — becoming dormant, as linguists put it — and 11 were critically endangered, with less than 10 speakers and a low chance of transmission to the next generation. Five more were severely endangered, with between 10 and 99 speakers left.
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In all, Lee’s work suggests that up to 96 percent of contact languages are either endangered or recently dormant, having lost the last known speakers — compared with less than 50 percent of the roughly 7,100 total languages worldwide. That means the risk of a contact language disappearing is nearly double that for all languages.
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This is sometimes due to ephemeral needs — the contact that gives rise to a language may not last very long. Lee points to Northern Territory Pidgin English, which came about through trades between British settlers in northern Australia and some Asian countries. “It quickly became obsolete when trading was halted after 11 years,” Lee says. In other cases, evidence points to deliberate efforts to suppress informal languages. Once the United States took over Hawaii, for example, it banned Hawaiian Pidgin (a combination of English and Hawaiian), as well as the indigenous Hawaiian language, from being used in schools starting in 1896.
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The fact that contact languages are not written, but passed down orally, means they can fade as younger generations move away to seek economic opportunity elsewhere, leaving traditions to elders. On the US Virgin Islands, English gradually became the language of choice and Negerhollands — a creole that originated around 1700 and combined Dutch, English, French, Spanish and African languages — became extinct in 1987.
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Attempts to preserve the endangered tongues can be challenge: Just as contact languages command less respect on the outside, the speakers themselves may be reluctant to view them as worth saving, Lee says.
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But efforts are afoot around the world. Among these, the Gullah Geechee Cultural Heritage Corridor Commission in South Carolina works to preserve the language of the Gullah people. The Sri Lanka Malay Association aims to maintain the language and traditions of this small ethnic group in Sri Lanka. The Creole Heritage Center and the Louisiana Folklife Center, both affiliated with the North State University of Louisiana, promote Louisiana Creole, which is based on French, some Spanish and native African languages used by enslaved people from the period when Louisiana was French-held territory.
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And in Canada, some who identify as Métis — the descendants of First Nations people (primarily Cree) and French fur traders — are working to preserve Michif, a contact language that arose among the Métis that combines Cree and French. It’s listed as critical by the Endangered Languages Project, which tracks at-risk languages including contact languages. There are an estimated 200 Michif speakers left in the world, though Lee estimates that the number of speakers fluent enough to pass on the language to subsequent generations is far lower.
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In the British Columbia area, the Michif Language Revitalization Circle was formed about two years ago and focuses on preserving Heritage Michif — one of four Michif dialects spoken in Canada and small pockets in the United States. “Luckily, in our group, three of us grew up exposed to our language,” says program coordinator Anita Barker, whose maternal grandfather was Cree and maternal grandmother was Métis. “We’re by no means speakers, but we at least heard it and could speak some when we were growing up.” The group is trying to create a written, phonetically read form of the language, working with Métis elders who still speak the language and members of the circle who had exposure to Michif growing up.
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Though many contact languages face endangerment, others go on to thrive. Gooden points to Nigerian Pidgin English. There are more than 500 languages spoken in Nigeria, and to facilitate cross-communication Nigerian Pidgin has become the universal, everyday tongue of the country.
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There have also been moves to legitimize contact languages. In 1987, the government of Haiti made Haitian Creole an official language alongside French. Similar efforts are currently underway in Jamaica.
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But then there are tongues like Baba Malay — a combination of Malay and Hokkien spoken by the Peranakan ethnic group in the Malaysian state of Malacca — that only older generations have held onto. That includes Lee’s own grandparents. As these languages diminish, so do the cultures that created them.
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10.1146/knowable-081020-1
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John Wenz is digital producer at Knowable Magazine.
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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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$\"Knowable$
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Covid-19 is an unprecedented health crisis. It is also emerging as an unprecedented economic crisis. On July 30, the US government reported the worst three-month drop in economic activity on record: a 9.5 percent decline in gross domestic product during 2020’s second quarter. Efforts to curb the coronavirus’ spread have shuttered US businesses and tossed more than 16.6 million people out of work.
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$\"Illustrated$
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CREDIT: JAMES PROVOST (CC BY-ND)
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Economist Till von Wachter
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UCLA
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But as extraordinary as the pandemic might be, the arguments over how the government should respond to such massive job losses are familiar, rehashing a longstanding debate over unemployment insurance, the state-federal partnership that provides payments to Americans who have lost their jobs: Does paying benefits to idled workers discourage them from finding new jobs?
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Till von Wachter, an economist at the University of California, Los Angeles, is faculty director of the California Policy Lab, which partners with the state’s policymakers to address social problems like poverty and crime. Von Wachter’s work focuses on the myriad consequences of job loss — people losing existing work through no fault of their own — and on the ways recessions affect new workers trying to break into the labor force. In 2016, he coauthored a review of studies examining the effects of unemployment insurance benefits in the Annual Review of Economics. As he sees it, there’s an essential role for unemployment insurance, and other government efforts to alleviate economic woes, in these troubled times.
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Knowable spoke with von Wachter, who was working from home during the pandemic, in mid-July — just as Congress and the White House were debating the details of a new coronavirus relief package, expected to exceed $1 trillion.
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This interview has been edited for length and clarity.
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Obviously unemployment has profound impacts on the people who have lost their jobs. Why do economists worry about it in the broader sense?
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Unemployment worries economists for a couple of reasons. A sudden loss of income is not good for the individual, but it’s also not good for society. You have a lot of workers cutting back on buying things at the same time as they are no longer generating the goods and services that other people consume, potentially leading to a vicious cycle. There’s also a concern that if people stay out of work too long, they become less employable, which impacts the overall economy’s productive potential.
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We also worry that people who are out of work will make short-term decisions that are damaging over the long run. People don’t want to starve or end up on the streets, so they shift spending to pay their bills. They could stop maintaining their health. They could stop investing in their children’s future. We see this often in developing countries that don’t have an unemployment insurance system.
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So the goal of unemployment insurance is to prevent that sort of short-term decision-making?
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That’s one goal. Unemployment insurance was instituted in the US during the 1930s, as part of Social Security and the New Deal. It’s a state-federal partnership. States set the parameters of the program, such as the scope and duration of benefits, and the tax rates that businesses will pay on their workers. The federal government comes in to help when states can’t keep up during a recession — which is something that has happened in each recession in recent memory.
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So, yes: The program protects workers from income loss, and prevents them from cutting back on education expenses and so on. But it’s also meant to keep displaced employees afloat long enough to find another job in a similar vein of work — to prevent a bunch of engineers or editors or other skilled people from ending up serving coffee, just to make ends meet. Taking such jobs can hurt a worker’s chances of returning to a higher-paying, skilled position later on.
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Unemployment insurance is also supposed to provide the economy with spending when it’s most needed. It allows people to keep paying their rent and doing their shopping. This spending helps to provide stimulus to the larger economy when it is most needed.
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So how would you characterize the unemployment triggered by the pandemic?
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There has been nothing like this, really, other than the Great Depression. In California, for example, between a third to half of workers in the labor force have filed for unemployment benefits, depending on which group you look at. That’s one of every two or three workers. Not all of them will receive benefits, or wind up in the official count, but if you take applications as a signal of need, certainly a very large number of people have been affected.
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This has been an incredibly concerning and interesting period for those of us who study the unemployment insurance system. It’s been really hard to figure out how to modify unemployment payments quickly enough to respond to the Covid-19 crisis.
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$\"Graph$
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Unemployment was severe during the Great Recession of 2008 and 2009, but levels soared even higher in the spring of 2020, as businesses shuttered to combat the spread of coronavirus.
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Why is it so difficult?
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In every recession, there’s a classic debate over the federal government contributions that extend benefits duration.
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Some economists and policymakers worry that at some point payments like these do more harm than good, because they may prevent people from returning to work. There have been a lot of studies about this. Most find that there is some temporary reduction in employment caused by insurance extensions, but that the cost is relatively small compared to the upside for workers and the economy.
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In the Covid recession, as you know, there has been an extension of benefits of $600 per week that pays many low-wage workers higher weekly earnings than they had before. It was a quick fix to get money to people. But it makes many observers uncomfortable. Does the extra $600 cause people not to work? Or are people not working because they’re unable to find jobs?
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It’s an interesting political question that could be directly informed by data, but the data are just coming in. We have a partnership here in California that lets us see information on unemployment insurance claims and benefits in close to real time. We’ve been learning a lot about who’s filing for benefits, including noting an important rise in additional claims filed by people who were laid off, filed claims, and then were laid off again. These claims have gone up as coronavirus surged in June and July. Also, we’ve found that a substantial fraction of individuals are working and receiving partial unemployment insurance, which is an interesting indicator of potential employment trends. Businesses may be hiring on a part-time basis, out of caution. We’re using these data to calculate the likely effects of different policies.
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In almost all other states, economists will have to wait months, if not years, to analyze such data. We could inform policy in a much better way if the US data from the unemployment insurance system were more available.
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Is the debate in Congress only about the $600 payments?
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The federal government is considering various ways of modifying the states’ programs, including supporting underutilized work-sharing programs [subsidized furloughs that prevent layoffs] or extending deadlines to funnel more money to small business via the Paycheck Protection Program [the federal program that pays companies to keep employees on payrolls during the coronavirus crisis]. But unemployment insurance is extremely cumbersome to reform, because you have to get 50 states to go along, and some have out-of-date IT systems that make that almost impossible.
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I think Congress would like to modify the $600 benefit to something more sensible, such as raising the benefit replacement rate. Currently, in most states the rate of these benefits replaces only half of a worker’s prior earnings. But states might be very slow to respond to anything more complex.
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What happens as the $600 payments expire?
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It is hard to know for sure without good data on family income. But pandemic-related job losses have affected a disproportionate number of low-wage workers. Certainly, if unemployment insurance income represented all a family earned, many people would fall below the poverty line without that key lifeline, lacking the money to pay for basic needs such as housing, food and transportation. We might be in for an eviction crisis if the stalemate in DC continues.
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Explore Knowable’s coronavirus coverage
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So what should leaders do?
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In addition to continuing unemployment payments in some form, it is important to keep curbing the spread of the virus, while making the delivery and consumption of goods and services safer. This would help consumer demand while making jobs for low-income workers safe.
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This can be done by setting safety standards that would allow the economy to better reconvene on a new equilibrium, helping prevent infections and supporting a sustainable reopening.
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For instance, there have been ongoing discussions about worker-safety regulations in delivery businesses, large warehouses, agriculture and meat-packing plants. Some supermarkets have plastic barriers for cashiers; some restaurants in Europe have plexiglass boxes around dining tables. These are problems that can be solved, with the right amount of support for businesses and some setting of expectations of what is the right thing to do. I think some states are trying, but I don’t see it happening at the federal level.
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What is work sharing, and why do you promote it as an important tool for managing unemployment benefits during the Covid-19 crisis?
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Work sharing, which is also known as short-time compensation, offers incentives to companies to reduce worker hours instead of implementing large-scale layoffs in response to a crisis like Covid-19. This helps keep workers attached to their employers, effectively putting the workforce on standby until conditions improve. It’s common in Europe, so many have questioned why it hasn’t been used as widely here in the US.
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Both Democrats and Republicans backed short-time compensation in the aftermath of the Great Recession, and passed a bill that subsidizes work-sharing programs in the US today. But take-up by employers has been relatively low, and I and other academic economists are lobbying Congress to provide more nimble, federally backed alternatives that would kick in during emergencies. The hope is to prevent the fraying of relationships between workers and firms and have more money in workers’ pockets at the end of the day.
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Companies benefit because they avoid the costs of massive turnover and training; and workers who retain their jobs keep their health insurance, and don’t risk suffering the kinds of lifetime earnings losses and health impacts experienced by those who lose a job. Those can be notable: In one study, we found that Pennsylvania workers who lost jobs during the 1982 recession in the US lost one to 1.5 years of life expectancy, on average.
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Recessions have similar effects on would-be workers looking for their first jobs, too. We found life expectancy among people who entered the job market during the 1982 recession was reduced by six to nine months.
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$\"Three$
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When researchers studied mortality rates and unemployment from 1992 to 2011, they found that people who had lost a job faced greater risk of dying than those who had not — especially during tough economic conditions. (A hazard ratio above 1 means the probability of death was higher for the jobless group. Quantiles refer to a range of economic conditions, with Q1 corresponding with boomtime labor market conditions, and Q6 characteristic of recessions.)
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So the pandemic could have a particularly harmful effect on young people just entering the workforce?
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Yes. Research has long shown that in a recession, the youngest workers, with no job experience, suffer large initial losses in earnings and employment. They tend to recover, but it takes 10 to 15 years: a few years for the better jobs to become available, a few years to search for those jobs and a few years to work your way up the ladder in that job.
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And even though the initial economic effect fades, there’s a decline in health and a rise in mortality as these unlucky young workers enter middle age. It seems to be that young workers with lower income have worse health behaviors — they drink more, have lower self-esteem and have more complicated lives marked by earlier marriage, fewer children and higher rates of divorce. The harms accumulate and express themselves in lower health outcomes.
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Could the Covid-19 crisis cause a depression? And, what is a depression?
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There is a clear definition for a recession, related to a drop in economic growth. I don’t think there’s a similar definition for a depression. You could think of it as an economic slowdown with great intensity and long duration. A sharp downturn with a quick rebound would probably not be called a depression — and there’s still hope that we could rebound quickly from this crisis.
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The Federal Reserve predicts we will be in a recession until at least until mid-2021, and usually labor markets take longer to recover. But I don’t think we have entered a phase of inevitability. We’ve found that 60 percent to 65 percent of people who apply for unemployment insurance in California believe they’ll be recalled by their companies, and the numbers are similar nationwide. That is lower than at the start of a crisis, but at least a good sign.
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By Eryn Brown 08.11.2020
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Eryn Brown is a writer and editor in Los Angeles.
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As Covid-19 has swept the United States, claims for unemployment insurance have soared — and reignited long-running debates about jobless aid. In June, Kentucky residents waited in line for assistance with claims.
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CREDIT: JOHN SOMMERS II / GETTY IMAGES
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Q&A — Economist Till von Wachter
\n\n
Why jobless payments serve the public good
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Amid political debate over benefits during the pandemic, a researcher explains why unemployment insurance and other government measures are crucial for the economy and employees to survive troubled times
\n\n
By Eryn Brown
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8.11.2020
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\n
Covid-19 is an unprecedented health crisis. It is also emerging as an unprecedented economic crisis. On July 30, the US government reported the worst three-month drop in economic activity on record: a 9.5 percent decline in gross domestic product during 2020’s second quarter. Efforts to curb the coronavirus’ spread have shuttered US businesses and tossed more than 16.6 million people out of work.
\n\n
But as extraordinary as the pandemic might be, the arguments over how the government should respond to such massive job losses are familiar, rehashing a longstanding debate over unemployment insurance, the state-federal partnership that provides payments to Americans who have lost their jobs: Does paying benefits to idled workers discourage them from finding new jobs?
\n\n
Till von Wachter, an economist at the University of California, Los Angeles, is faculty director of the California Policy Lab, which partners with the state’s policymakers to address social problems like poverty and crime. Von Wachter’s work focuses on the myriad consequences of job loss — people losing existing work through no fault of their own — and on the ways recessions affect new workers trying to break into the labor force. In 2016, he coauthored a review of studies examining the effects of unemployment insurance benefits in the Annual Review of Economics. As he sees it, there’s an essential role for unemployment insurance, and other government efforts to alleviate economic woes, in these troubled times.
\n\n
Knowable spoke with von Wachter, who was working from home during the pandemic, in mid-July — just as Congress and the White House were debating the details of a new coronavirus relief package, expected to exceed $1 trillion.
\n\n
This interview has been edited for length and clarity.
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Obviously unemployment has profound impacts on the people who have lost their jobs. Why do economists worry about it in the broader sense?
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Unemployment worries economists for a couple of reasons. A sudden loss of income is not good for the individual, but it’s also not good for society. You have a lot of workers cutting back on buying things at the same time as they are no longer generating the goods and services that other people consume, potentially leading to a vicious cycle. There’s also a concern that if people stay out of work too long, they become less employable, which impacts the overall economy’s productive potential.
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We also worry that people who are out of work will make short-term decisions that are damaging over the long run. People don’t want to starve or end up on the streets, so they shift spending to pay their bills. They could stop maintaining their health. They could stop investing in their children’s future. We see this often in developing countries that don’t have an unemployment insurance system.
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So the goal of unemployment insurance is to prevent that sort of short-term decision-making?
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That’s one goal. Unemployment insurance was instituted in the US during the 1930s, as part of Social Security and the New Deal. It’s a state-federal partnership. States set the parameters of the program, such as the scope and duration of benefits, and the tax rates that businesses will pay on their workers. The federal government comes in to help when states can’t keep up during a recession — which is something that has happened in each recession in recent memory.
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So, yes: The program protects workers from income loss, and prevents them from cutting back on education expenses and so on. But it’s also meant to keep displaced employees afloat long enough to find another job in a similar vein of work — to prevent a bunch of engineers or editors or other skilled people from ending up serving coffee, just to make ends meet. Taking such jobs can hurt a worker’s chances of returning to a higher-paying, skilled position later on.
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Unemployment insurance is also supposed to provide the economy with spending when it’s most needed. It allows people to keep paying their rent and doing their shopping. This spending helps to provide stimulus to the larger economy when it is most needed.
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So how would you characterize the unemployment triggered by the pandemic?
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There has been nothing like this, really, other than the Great Depression. In California, for example, between a third to half of workers in the labor force have filed for unemployment benefits, depending on which group you look at. That’s one of every two or three workers. Not all of them will receive benefits, or wind up in the official count, but if you take applications as a signal of need, certainly a very large number of people have been affected.
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This has been an incredibly concerning and interesting period for those of us who study the unemployment insurance system. It’s been really hard to figure out how to modify unemployment payments quickly enough to respond to the Covid-19 crisis.
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Why is it so difficult?
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In every recession, there’s a classic debate over the federal government contributions that extend benefits duration.
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Some economists and policymakers worry that at some point payments like these do more harm than good, because they may prevent people from returning to work. There have been a lot of studies about this. Most find that there is some temporary reduction in employment caused by insurance extensions, but that the cost is relatively small compared to the upside for workers and the economy.
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In the Covid recession, as you know, there has been an extension of benefits of $600 per week that pays many low-wage workers higher weekly earnings than they had before. It was a quick fix to get money to people. But it makes many observers uncomfortable. Does the extra $600 cause people not to work? Or are people not working because they’re unable to find jobs?
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It’s an interesting political question that could be directly informed by data, but the data are just coming in. We have a partnership here in California that lets us see information on unemployment insurance claims and benefits in close to real time. We’ve been learning a lot about who’s filing for benefits, including noting an important rise in additional claims filed by people who were laid off, filed claims, and then were laid off again. These claims have gone up as coronavirus surged in June and July. Also, we’ve found that a substantial fraction of individuals are working and receiving partial unemployment insurance, which is an interesting indicator of potential employment trends. Businesses may be hiring on a part-time basis, out of caution. We’re using these data to calculate the likely effects of different policies.
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In almost all other states, economists will have to wait months, if not years, to analyze such data. We could inform policy in a much better way if the US data from the unemployment insurance system were more available.
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Is the debate in Congress only about the $600 payments?
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The federal government is considering various ways of modifying the states’ programs, including supporting underutilized work-sharing programs [subsidized furloughs that prevent layoffs] or extending deadlines to funnel more money to small business via the Paycheck Protection Program [the federal program that pays companies to keep employees on payrolls during the coronavirus crisis]. But unemployment insurance is extremely cumbersome to reform, because you have to get 50 states to go along, and some have out-of-date IT systems that make that almost impossible.
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I think Congress would like to modify the $600 benefit to something more sensible, such as raising the benefit replacement rate. Currently, in most states the rate of these benefits replaces only half of a worker’s prior earnings. But states might be very slow to respond to anything more complex.
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What happens as the $600 payments expire?
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It is hard to know for sure without good data on family income. But pandemic-related job losses have affected a disproportionate number of low-wage workers. Certainly, if unemployment insurance income represented all a family earned, many people would fall below the poverty line without that key lifeline, lacking the money to pay for basic needs such as housing, food and transportation. We might be in for an eviction crisis if the stalemate in DC continues.
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Explore Knowable’s coronavirus coverage
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So what should leaders do?
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In addition to continuing unemployment payments in some form, it is important to keep curbing the spread of the virus, while making the delivery and consumption of goods and services safer. This would help consumer demand while making jobs for low-income workers safe.
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This can be done by setting safety standards that would allow the economy to better reconvene on a new equilibrium, helping prevent infections and supporting a sustainable reopening.
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For instance, there have been ongoing discussions about worker-safety regulations in delivery businesses, large warehouses, agriculture and meat-packing plants. Some supermarkets have plastic barriers for cashiers; some restaurants in Europe have plexiglass boxes around dining tables. These are problems that can be solved, with the right amount of support for businesses and some setting of expectations of what is the right thing to do. I think some states are trying, but I don’t see it happening at the federal level.
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What is work sharing, and why do you promote it as an important tool for managing unemployment benefits during the Covid-19 crisis?
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Work sharing, which is also known as short-time compensation, offers incentives to companies to reduce worker hours instead of implementing large-scale layoffs in response to a crisis like Covid-19. This helps keep workers attached to their employers, effectively putting the workforce on standby until conditions improve. It’s common in Europe, so many have questioned why it hasn’t been used as widely here in the US.
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Both Democrats and Republicans backed short-time compensation in the aftermath of the Great Recession, and passed a bill that subsidizes work-sharing programs in the US today. But take-up by employers has been relatively low, and I and other academic economists are lobbying Congress to provide more nimble, federally backed alternatives that would kick in during emergencies. The hope is to prevent the fraying of relationships between workers and firms and have more money in workers’ pockets at the end of the day.
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Companies benefit because they avoid the costs of massive turnover and training; and workers who retain their jobs keep their health insurance, and don’t risk suffering the kinds of lifetime earnings losses and health impacts experienced by those who lose a job. Those can be notable: In one study, we found that Pennsylvania workers who lost jobs during the 1982 recession in the US lost one to 1.5 years of life expectancy, on average.
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Recessions have similar effects on would-be workers looking for their first jobs, too. We found life expectancy among people who entered the job market during the 1982 recession was reduced by six to nine months.
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So the pandemic could have a particularly harmful effect on young people just entering the workforce?
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Yes. Research has long shown that in a recession, the youngest workers, with no job experience, suffer large initial losses in earnings and employment. They tend to recover, but it takes 10 to 15 years: a few years for the better jobs to become available, a few years to search for those jobs and a few years to work your way up the ladder in that job.
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And even though the initial economic effect fades, there’s a decline in health and a rise in mortality as these unlucky young workers enter middle age. It seems to be that young workers with lower income have worse health behaviors — they drink more, have lower self-esteem and have more complicated lives marked by earlier marriage, fewer children and higher rates of divorce. The harms accumulate and express themselves in lower health outcomes.
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Could the Covid-19 crisis cause a depression? And, what is a depression?
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There is a clear definition for a recession, related to a drop in economic growth. I don’t think there’s a similar definition for a depression. You could think of it as an economic slowdown with great intensity and long duration. A sharp downturn with a quick rebound would probably not be called a depression — and there’s still hope that we could rebound quickly from this crisis.
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The Federal Reserve predicts we will be in a recession until at least until mid-2021, and usually labor markets take longer to recover. But I don’t think we have entered a phase of inevitability. We’ve found that 60 percent to 65 percent of people who apply for unemployment insurance in California believe they’ll be recalled by their companies, and the numbers are similar nationwide. That is lower than at the start of a crisis, but at least a good sign.
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10.1146/knowable-081020-2
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Eryn Brown is a writer and editor in Los Angeles.
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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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$\"Knowable$
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\n
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PRODUCED BY TIEN NGUYEN FOR KNOWABLE MAGAZINE
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News coverage of the coronavirus pandemic has leaned heavily on constantly updated data: number of cases, number of deaths and more. Presented in charts, graphs, maps and animations, the data can help tell the story. Sometimes, though, the visualizations can be misleading or reveal one aspect of the pandemic while hiding another. In this video, Knowable Magazine asks two data visualization researchers for advice on how to read a few common types of Covid-19 graphics. They share what these graphs can and cannot tell us about the pandemic.
READ MORE: Why scientists need to be better at data visualization
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Tien Nguyen is a freelance journalist, video producer, and reformed PhD chemist. Her writing has been featured in Chemical & Engineering News, Nature, Vice News, TED-Ed, and other outlets. Follow her on Twitter @mustlovescience.
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CREDIT: KNOWABLE MAGAZINE
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Videos
\n
Data viz experts explain Covid-19 graphics | Things to Know
\n
VIDEO: Scientists break down what some popular visualizations of the pandemic can and cannot tell us
\n
\n Video by Tien Nguyen \n \n
\n
5.18.2020
\n
News coverage of the coronavirus pandemic has leaned heavily on constantly updated data: number of cases, number of deaths and more. Presented in charts, graphs, maps and animations, the data can help tell the story. Sometimes, though, the visualizations can be misleading or reveal one aspect of the pandemic while hiding another. In this video, Knowable Magazine asks two data visualization researchers for advice on how to read a few common types of Covid-19 graphics. They share what these graphs can and cannot tell us about the pandemic.
READ MORE: Why scientists need to be better at data visualization
\n
\n
\n
\n
10.1146/knowable-051820-1
\n
\n\n
\n
Tien Nguyen is a freelance journalist, video producer, and reformed PhD chemist. Her writing has been featured in Chemical & Engineering News, Nature, Vice News, TED-Ed, and other outlets. Follow her on Twitter @mustlovescience.
\n
\n
This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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Renewable energy experts have long hoped that solar and wind power would someday become the cheapest way to generate electricity, allowing the world to shift away from fossil fuel. That day has now arrived, much sooner than expected, says Faaiqa Hartley, an energy economist at the Energy Research Centre of the University of Cape Town, South Africa. It could pave the way for renewables to eventually account for the lion’s share of global electricity production, far beyond today’s 26 percent share.
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CREDIT: JAMES PROVOST (CC BY-ND)
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Economist Faaiqa Hartley
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University of Cape Town
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Knowable Magazine spoke with Hartley, who coauthored a review on the subject in the 2019 Annual Review of Resource Economics, about what crossing this threshold means, particularly for developing countries, and about some of the new challenges that are likely to arise as the world transitions to a renewable future.
This conversation has been edited for length and clarity.
Prices for renewable electricity have been falling for many years. What’s surprising about what’s happening now?
Experts have been expecting a decline in prices, yes. But what has been such a game changer is the rate at which these prices have fallen. Every year for the last decade, electricity from solar and wind has ended up costing less than experts predicted it would.
Renewable energy is now comparable with the cost of building new coal and nuclear capacity. Existing, older power plants already have the capital investment sunk, so they are cheaper — but, in the case of South Africa at least, many of these plants are reaching retirement ages.
This has changed the landscape. There is now a cheap, clean alternative for power generation. There’s no longer this problem of do we decarbonize our power sector and have more expensive electricity — in which case it negatively affects our economy. We’re now finding that because it’s cheaper, it’s actually beneficial to produce greener electricity.
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Solar and wind power used to be the most expensive ways to generate electricity. Now they are among the cheapest. (Some data for coal not shown.)
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How does that affect the wider economy?
Switching to renewables requires far less investment into your power sector than if you were to build new coal or nuclear power plants. That means a lower electricity price, and that has impacts on everything in the economy. A lower electricity price reduces the cost of production, and increases profit. At the same time, it helps households, because spending less on power means you can spend more on other things. From that perspective, you’re actually stimulating the economy when you’re building renewable energy. In South Africa you’re looking at the potential for more than a million additional jobs being created by 2050 if we move to renewable energy.
You’ve suggested that a surge in renewable sources of electricity will be especially beneficial for the world’s poorest people. Why is that?
In many developing countries, not everyone has access to electricity, because the infrastructure required to connect them to the system is not available. Renewable technologies can allow countries to skip the need of having extensive power grids, as energy production can be developed closer to centers of demand and, in the case of solar, can even be placed on people’s roofs. This is very powerful if one considers that these households currently do not have electricity. Even in South Africa, which is considered to be one of the leading countries on the continent in terms of infrastructure development, around 20 percent of people living in rural areas don’t have electricity.
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Does the lower cost of renewables mean there is no longer a good reason to build fossil-fuel electric generating plants?
It depends on where in the world you are. Different countries have access to different types of resources. Here in South Africa, it makes sense for us to build renewables. We’ve got a very well-developed grid, and if we’re generating solar or wind power it’s just a matter of connecting those sources to the grid. South Africa has sufficient land to build these power plants. And I think more importantly, because the resource, the solar and wind, is so good in South Africa we can basically build it anywhere in the country without making it significantly less efficient. But some other countries, such as Bangladesh, don’t have as much land suitable for building renewables on a large scale.
How long would it take a country like South Africa to make the transition? It gets only about 10 percent of its electricity from renewables today.
South Africa is actually at the perfect place to be switching to renewable energy. A lot of our coal power plants will be decommissioned by 2030 to 2040, so we need to start building new capacity. The question is, do we build new coal capacity, new nuclear capacity, or do we build renewables? According to predictions we’ve done, South Africa could have 70 percent to 80 percent from renewables by 2050.
Will that happen automatically, or will policy changes be required?
In South Africa, we do need policy intervention because the current policy is not to shift to renewable energy at the pace that’s needed. Numerous studies, including ours, have shown that it’s the least-cost path for the country. But current policy still plans the building of new coal plants to 2050.
The government’s reason is that there’s no transition plan in place for the coal-mining sector. You’ve got lobbying groups who benefit from coal-mining production. You’ve got unions whose workers are in the coal industry. The government needs to find a balance. While you are creating more jobs throughout the economy with renewable energy, coal miners are losing their jobs, so you do need a plan in place that either helps to reskill these workers or, if they are near retirement age, looks at alternative financial arrangements. You need policies in place that think about how to maybe put more manufacturing in coal-mining regions, or wind farms or solar farms there. So those are things that need to be planned.
\n
\n $\"Map$
\n\n
Much of the United States is routinely breezy, as highlighted on this map of average wind speeds, making wind a rich potential source of electricity.
\n \n \n \n
Is that happening?
There are plans, but they’re very much in their infancy. If you spoke to me about this two or three years ago, or even maybe at the start of last year, there was really nothing suggesting a move to renewable energy. Whereas now, there’s far stronger support for shifting to renewables. It’s just about getting the policies in place.
You’ve noted that energy systems that rely heavily on renewables face what’s called the “systems integration challenge.” Can you explain what that is?
Sure. The systems integration challenge is the complexity of always ensuring that there is enough power in the system. The sun does not always shine and the wind does not always blow, so there may be periods of time in which a highly renewable-dependent energy system may not be able to produce enough electricity. During this time, one would have to have other technologies to fill the gap.
The challenge is being able to maintain this shifting between technologies in an efficient manner, so that people don’t experience blackouts or brownouts. With a renewable system, one needs to consider where and when it will be windy or sunny, how far into the future we can actually predict this and how the endowment will change over time, particularly in light of climate change. These questions are quite different from the ones of before.
This only becomes a challenge when wind and solar contributes more than 20 percent of electricity production. Current levels are quite low in many countries. although there are examples of countries such as Denmark where they are managing a high share quite well.
South Africa, along with much of Africa actually, is very well-endowed with solar and wind resources. It is therefore highly likely that renewables will always be producing power because when the sun sets we still have wind. For South Africa, estimates show full coverage of demand for about 70 percent of the year, with the remaining 30 percent of the year having coverage of around 70 percent to 90 percent.
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\n $\"Map$
\n\n
South Africa has enormous potential for generating solar electricity nationwide, as highlighted in this map showing possible photovoltaic power output over one year.
\n \n \n \n
How can the system cover those shortfalls?
There is the option to use gas, and with the technological advancement in batteries, storing solar- or wind-produced energy for later is increasingly becoming an option as well. And we have in the past been able to create agreements with industry in which they would shift their use of electricity to times when there is less demand in the system. You can also shift households’ demand for electricity by having a tariff structure where the price is higher when demand normally peaks. That’s been done in other countries, as well.
Will clean electricity bring other environmental benefits?
We do need to find ways of further reducing carbon emissions — but that doesn’t necessarily have to come from the power sector. For example, in the transport sector, you can now switch away from fossil fuels to electric vehicles, because you’re using a clean source of electricity. That will reduce emissions. If the transport sector is no longer using fossil fuels, there is no need to produce high volumes of petrol and diesel, so you reduce emissions in the fossil fuel production sector as well. But all this does need government support for all of these things to align.
Are you optimistic that society will manage the transition to renewables?
I am. I’m actually very optimistic about it. I think it’s something that will help significantly in a country like South Africa, where you’ve got the bulk of emissions being produced by the electricity sector. You’ve got industry that is so electricity-intensive, and a lot of that industry is also producing for the export market. To have competitively priced green electricity is definitely exciting.
\n","field_all_authors":"
\n \n \n \n By\n\n \n Bob Holmes\n \n \n \n \n 01.14.2020\n
\n","field_ar_article":{"arguments":[]},"field_author_bios":"
\n
Bob Holmes is a science writer based in Edmonton, Canada.
\n
\n","field_banner_alt":"Photo shows solar panels piled up in a remote area of South Africa.","field_banner_title":"Solar energy","field_caption":"
Solar panels await installation in the South African desert. Like many developing nations, South Africa now has an opportunity to make a major shift to forms of renewable energy such as solar and wind power, says energy economist Faaiqa Hartley.
\n","field_credit":"
CREDIT: IMAGEBROKER / ALAMY STOCK PHOTO
","field_doi":"10.1146/knowable-011420-1","field_headline":"Q&A — Energy economist Faaiqa Hartley","field_headline_url":{"arguments":["collection","qa"],"type":"client"},"field_is_hero":"1","metatags":{"referrer":"origin","title":"Why green energy finally makes economic sense","description":" Solar and wind generators have suddenly become just as cheap as other ways to produce electric power","google_plus_name":"Why green energy finally makes economic sense","og_title":"Why green energy finally makes economic sense","og_site_name":"Knowable Magazine | Annual Reviews","og_type":"article","twitter_cards_type":"summary_large_image","canonical_url":"/article/sustainability/2020/cost-of-renewable-energy","dcterms_description":" Solar and wind generators have suddenly become just as cheap as other ways to produce electric power","dcterms_identifier":"10.1146/knowable-011420-1","dcterms_publisher":"Annual Reviews","dcterms_title":"Why green energy finally makes economic sense","dcterms_type":"article","fb_admins":"1642929092406128","google_plus_description":" Solar and wind generators have suddenly become just as cheap as other ways to produce electric power","google_plus_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/397/renewable-energy-1600x600_2.jpg?itok=HhLN93Ak","citation_author":"","citation_journal_title":"Knowable Magazine | Annual Reviews","citation_publication_date":"Tuesday, January 14, 2020 - 07:00","citation_title":"Why green energy finally makes economic sense","article_modified_time":"Tuesday, January 14, 2020 - 18:22","article_published_time":"Tuesday, January 14, 2020 - 07:00","og_description":" Solar and wind generators have suddenly become just as cheap as other ways to produce electric power","og_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/397/renewable-energy-1600x600_2.jpg?itok=HhLN93Ak","og_image_height":"600","og_image_type":"image/jpeg","og_image_url":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/397/renewable-energy-1600x600_2.jpg?itok=HhLN93Ak","og_image_width":"1600","og_updated_time":"Tuesday, January 14, 2020 - 18:22","og_url":"/article/sustainability/2020/cost-of-renewable-energy","twitter_cards_description":" Solar and wind generators have suddenly become just as cheap as other ways to produce electric power","twitter_cards_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/397/renewable-energy-1600x600_2.jpg?itok=HhLN93Ak","twitter_cards_image_height":"600","twitter_cards_image_width":"1600","twitter_cards_page_url":"/article/sustainability/2020/cost-of-renewable-energy","twitter_cards_site":"@knowablemag","twitter_cards_title":"Why green energy finally makes economic sense","dc_identifier":"10.1146/knowable-011420-1","pocket-site-verification":"665d7e2e5dc1fa27727a154d5c4e80"},"field_primary_author":"By Bob Holmes","field_published":"2020-01-14","field_republish_html":"
Q&A — Energy economist Faaiqa Hartley
\n
Why green energy finally makes economic sense
\n
Solar and wind generators have suddenly become just as cheap as other ways to produce electric power
\n
\n By Bob Holmes \n \n
\n
1.14.2020
\n
Renewable energy experts have long hoped that solar and wind power would someday become the cheapest way to generate electricity, allowing the world to shift away from fossil fuel. That day has now arrived, much sooner than expected, says Faaiqa Hartley, an energy economist at the Energy Research Centre of the University of Cape Town, South Africa. It could pave the way for renewables to eventually account for the lion’s share of global electricity production, far beyond today’s 26 percent share.
Knowable Magazine spoke with Hartley, who coauthored a review on the subject in the 2019 Annual Review of Resource Economics, about what crossing this threshold means, particularly for developing countries, and about some of the new challenges that are likely to arise as the world transitions to a renewable future.
This conversation has been edited for length and clarity.
Prices for renewable electricity have been falling for many years. What’s surprising about what’s happening now?
Experts have been expecting a decline in prices, yes. But what has been such a game changer is the rate at which these prices have fallen. Every year for the last decade, electricity from solar and wind has ended up costing less than experts predicted it would.
Renewable energy is now comparable with the cost of building new coal and nuclear capacity. Existing, older power plants already have the capital investment sunk, so they are cheaper — but, in the case of South Africa at least, many of these plants are reaching retirement ages.
This has changed the landscape. There is now a cheap, clean alternative for power generation. There’s no longer this problem of do we decarbonize our power sector and have more expensive electricity — in which case it negatively affects our economy. We’re now finding that because it’s cheaper, it’s actually beneficial to produce greener electricity.
How does that affect the wider economy?
Switching to renewables requires far less investment into your power sector than if you were to build new coal or nuclear power plants. That means a lower electricity price, and that has impacts on everything in the economy. A lower electricity price reduces the cost of production, and increases profit. At the same time, it helps households, because spending less on power means you can spend more on other things. From that perspective, you’re actually stimulating the economy when you’re building renewable energy. In South Africa you’re looking at the potential for more than a million additional jobs being created by 2050 if we move to renewable energy.
You’ve suggested that a surge in renewable sources of electricity will be especially beneficial for the world’s poorest people. Why is that?
In many developing countries, not everyone has access to electricity, because the infrastructure required to connect them to the system is not available. Renewable technologies can allow countries to skip the need of having extensive power grids, as energy production can be developed closer to centers of demand and, in the case of solar, can even be placed on people’s roofs. This is very powerful if one considers that these households currently do not have electricity. Even in South Africa, which is considered to be one of the leading countries on the continent in terms of infrastructure development, around 20 percent of people living in rural areas don’t have electricity.
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Does the lower cost of renewables mean there is no longer a good reason to build fossil-fuel electric generating plants?
It depends on where in the world you are. Different countries have access to different types of resources. Here in South Africa, it makes sense for us to build renewables. We’ve got a very well-developed grid, and if we’re generating solar or wind power it’s just a matter of connecting those sources to the grid. South Africa has sufficient land to build these power plants. And I think more importantly, because the resource, the solar and wind, is so good in South Africa we can basically build it anywhere in the country without making it significantly less efficient. But some other countries, such as Bangladesh, don’t have as much land suitable for building renewables on a large scale.
How long would it take a country like South Africa to make the transition? It gets only about 10 percent of its electricity from renewables today.
South Africa is actually at the perfect place to be switching to renewable energy. A lot of our coal power plants will be decommissioned by 2030 to 2040, so we need to start building new capacity. The question is, do we build new coal capacity, new nuclear capacity, or do we build renewables? According to predictions we’ve done, South Africa could have 70 percent to 80 percent from renewables by 2050.
Will that happen automatically, or will policy changes be required?
In South Africa, we do need policy intervention because the current policy is not to shift to renewable energy at the pace that’s needed. Numerous studies, including ours, have shown that it’s the least-cost path for the country. But current policy still plans the building of new coal plants to 2050.
The government’s reason is that there’s no transition plan in place for the coal-mining sector. You’ve got lobbying groups who benefit from coal-mining production. You’ve got unions whose workers are in the coal industry. The government needs to find a balance. While you are creating more jobs throughout the economy with renewable energy, coal miners are losing their jobs, so you do need a plan in place that either helps to reskill these workers or, if they are near retirement age, looks at alternative financial arrangements. You need policies in place that think about how to maybe put more manufacturing in coal-mining regions, or wind farms or solar farms there. So those are things that need to be planned.
Is that happening?
There are plans, but they’re very much in their infancy. If you spoke to me about this two or three years ago, or even maybe at the start of last year, there was really nothing suggesting a move to renewable energy. Whereas now, there’s far stronger support for shifting to renewables. It’s just about getting the policies in place.
You’ve noted that energy systems that rely heavily on renewables face what’s called the “systems integration challenge.” Can you explain what that is?
Sure. The systems integration challenge is the complexity of always ensuring that there is enough power in the system. The sun does not always shine and the wind does not always blow, so there may be periods of time in which a highly renewable-dependent energy system may not be able to produce enough electricity. During this time, one would have to have other technologies to fill the gap.
The challenge is being able to maintain this shifting between technologies in an efficient manner, so that people don’t experience blackouts or brownouts. With a renewable system, one needs to consider where and when it will be windy or sunny, how far into the future we can actually predict this and how the endowment will change over time, particularly in light of climate change. These questions are quite different from the ones of before.
This only becomes a challenge when wind and solar contributes more than 20 percent of electricity production. Current levels are quite low in many countries. although there are examples of countries such as Denmark where they are managing a high share quite well.
South Africa, along with much of Africa actually, is very well-endowed with solar and wind resources. It is therefore highly likely that renewables will always be producing power because when the sun sets we still have wind. For South Africa, estimates show full coverage of demand for about 70 percent of the year, with the remaining 30 percent of the year having coverage of around 70 percent to 90 percent.
How can the system cover those shortfalls?
There is the option to use gas, and with the technological advancement in batteries, storing solar- or wind-produced energy for later is increasingly becoming an option as well. And we have in the past been able to create agreements with industry in which they would shift their use of electricity to times when there is less demand in the system. You can also shift households’ demand for electricity by having a tariff structure where the price is higher when demand normally peaks. That’s been done in other countries, as well.
Will clean electricity bring other environmental benefits?
We do need to find ways of further reducing carbon emissions — but that doesn’t necessarily have to come from the power sector. For example, in the transport sector, you can now switch away from fossil fuels to electric vehicles, because you’re using a clean source of electricity. That will reduce emissions. If the transport sector is no longer using fossil fuels, there is no need to produce high volumes of petrol and diesel, so you reduce emissions in the fossil fuel production sector as well. But all this does need government support for all of these things to align.
Are you optimistic that society will manage the transition to renewables?
I am. I’m actually very optimistic about it. I think it’s something that will help significantly in a country like South Africa, where you’ve got the bulk of emissions being produced by the electricity sector. You’ve got industry that is so electricity-intensive, and a lot of that industry is also producing for the export market. To have competitively priced green electricity is definitely exciting.
\n
\n
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10.1146/knowable-011420-1
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\n\n
\n
Bob Holmes is a science writer based in Edmonton, Canada.
\n
\n
This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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Every year, people haul 1 to 3 trillion fish from the ocean. There’s little doubt that this is too many — fish populations have collapsed worldwide. But there’s another thing we are doing to fish: By killing them in such large numbers, we are exerting enormous evolutionary selection pressure. The adaptive changes that result could increase the chance that fish species will survive, but may pose a problem for the people who depend on them.
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By preferentially catching the kind of fish we like — usually big ones — we are inevitably creating a disadvantageous situation for such fish. They’re less likely to survive and reproduce, which reduces the presence of their genes in the next generation. We are, in effect, creating evolutionary pressure for fish to be small. In that way, policies dictating that only large fish should be caught, and small ones left alone, could be counterproductive.
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$\"Cartoon$
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CREDIT: JAMES PROVOST (CC BY-ND)
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Evolutionary biologist Mikko Heino
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University of Bergen, Norway
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Mikko Heino, an evolutionary biologist at the University of Bergen in Norway, has spent more than 20 years trying to document and understand how humans are changing the way that fish evolve. Because it’s very hard to directly demonstrate genetic changes due to fishing, he has used a diversity of other approaches, from lab experiments to historical data analysis to computer modeling of long-term evolution.
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As Heino and two coauthors explain in the Annual Review of Ecology, Evolution, and Systematics, there probably is no way for us to catch fish without evolutionary side effects. Yet he believes that taking evolution into account might put an end to well-intended but ill-advised policies and help develop more sustainable ways to manage fisheries.
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This interview has been edited for length and clarity.
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Overfishing is a global issue today, and it seems impossible to inventory all populations to know what exactly is going on. So how do you go about studying the impacts of fisheries?
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First of all, we have learned a lot from studying fisheries where there is a tradition of data collection. In Norway, for example, these data go back almost 90 years, which reflects the very high importance of some of these populations to local economies. Because those catches were naturally fluctuating, there was a desire to better understand where these fluctuations were coming from, because they had such a huge impact on people’s livelihoods.
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By using these kinds of data, we were able to show, for example, that a dramatic collapse of the cod population off the coast of Canada in the late 1980s and early 1990s was preceded by a decrease in the average size of individuals, and earlier reproductive maturation. Follow-up studies have found that similar patterns are affecting dozens of other commercially important fish.
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To really demonstrate evolution, one has to show genetic change. Have you been able to?
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Not yet. All our evidence so far is based on changes in the appearance of the fish, not their genes. I have been involved in a number of projects attempting to show genetic change, but it turns out to be challenging. This partly reflects the highly polygenic nature of traits such as body size and maturation. Almost every gene has an effect on body size, and so does the environment. The selection response is therefore quite spread out across the genome, and not very large at any single gene. Yet the fact that these changes are so common does suggest to me that adaptive evolution is the most likely explanation.
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Another way we are approaching this is by doing experiments in the lab, often using smaller species such as guppies, to show what the evolutionary effects may be when we regularly remove the largest individuals. These experiments are necessarily a simplification of real life, but they may help to focus our attention on aspects we may not have thought about, such as the importance of cannibalism when different generations live in the same place, which is the case in certain populations of cod, for example.
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Last but not least, we can feed the historical and experimental data into computer models to extrapolate our findings into the future and find out what might happen after many generations, or at much larger scales. These are things that would otherwise be too expensive or time-consuming to investigate, and modeling them may help us understand patterns we observe in real life, or even inform new policies and regulations.
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$\"Photograph$
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In 2002, an experiment at SUNY Stony Brook found that selectively removing the largest or smallest fish from experimental populations of Atlantic silverside (Menidia menidia) could create a twofold difference in body weight after four generations. (Left: fish from the original population. Right top: population in which small individuals were removed. Right bottom: population in which large individuals were removed.) In 2019, a team including the original authors did a genetic analysis of some of the fish, which had been stored in a freezer after the experiment. They found that many growth-related genes were involved in the changes, but that the precise nature of the changes differed from one experiment to the next. In some cases, whole blocks of genes changed together, enabling a rapid response to the selective pressure exerted by the experiment. The findings mimic the kinds of effects that selective fishing could create and show that there’s more than one genetic way for fish to evolve to get smaller or larger.
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CREDIT: D.O. CONOVER AND S.B. MUNCH / SCIENCE 2002
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Usually, when human activities are a threat to plants or animals, there is a sense of relief when scientists discover they are evolving in response. So why would it be bad news if fish do the same?
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Well, it depends whether you take the perspective of the fish, or of humans using them as a resource.
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For the fish, it is probably a good thing, as it will make them more resilient to fishing. And from a larger sustainability perspective, that is also good for us. But if you are interested in maintaining the same levels of yield, the problem is that fish are likely to evolve in a way that lowers fisheries’ productivity. So populations and species may still be around, but they will become types that are less valuable for us.
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As human populations keep increasing, this is a problem for food security, perhaps not in Western economies, but in some developing ones, and in many local communities that depend on fisheries.
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That being said, fisheries can also lead fish into a kind of evolutionary trap. Evolution is myopic — it can only respond to changes in the environment, not predict them, so it will reflect the characteristics that were beneficial in the recent past, with no guarantees for the future. But when we push fish to evolve a smaller body size, this may, for example, decrease their physiological ability to make the long spawning migrations that species such as cod and tuna depend on.
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In the review, you point out that even if we don’t fish selectively, so that every individual fish has the same chance of being caught, we are still causing evolution. How so? Is there really no way to avoid this?
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It is essentially unavoidable. When we fish, we impact the circumstances for the population, because we are removing individuals and increasing the rate of mortality. Even if the relative risk of dying is exactly the same for all the fish in the population, irrespective of their traits, if you elevate overall risk — which we always do when we fish — it will cause selection for fish to live faster. This means they will be maturing and reproducing at earlier ages and at smaller sizes, because the ones that wait too long may not get to reproduce at all.
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The only way to minimize selection would be for our fisheries to exactly replace the impact of natural predators, by removing or outcompeting them, as we are arguably doing to some extent. But from a conservation point of view, eliminating large marine predators is also problematic, of course.
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That is not very encouraging. Is there nothing else we can do to minimize our impact?
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The most robust advice I can give is that when fishing for single species, aiming for intermediate-sized fish, or at least not singling out the large ones, is probably the best approach to reduce selection.
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$\"Photograph$
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Captain Tony Tarracino and his wife and daughter show off a catch of goliath grouper in 1958, in the Florida Keys. Big fish have been getting smaller ever since. A 2009 study found that the average size of trophy fish displayed in pictures like this was less than half what it was in the late 1950s.
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CREDIT: FLORIDA KEYS PUBLIC LIBRARY / FLICKR
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That is almost the opposite of what many fishery practices and regulations currently prescribe, which is to release or avoid small fish and only keep the big ones. Why do these rules exist?
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The classical thinking in fisheries biology goes that we should catch fish when they reach their most productive size, while leaving alive the ones that are still going to grow. Conveniently, this is also fully compatible with the Western desire to eat larger fish. But it is not as sustainable as we like to believe.
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Does this mean that more recent regulations requiring fishing vessels to land everything they catch, even if it can’t be sold — which many fishermen consider to be wasteful — are indeed a good idea?
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They are a move in the right direction, because it makes some selection pressures less strong. But it would be naive to believe that this solves the whole problem. Like I said, a large part of these selective pressures is the result of shortening average lifespans, which is caused by the increased mortality risk. This will still occur if you are harvesting smaller individuals as well, unless you dramatically reduce the harvest of large ones. So lowering the absolute levels of harvesting will also be important.
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This is desirable for many reasons, of course, even without considering the evolutionary perspective. If fish populations are large, you can get a larger catch for the same investment of effort, fuel and salary. So there are good arguments for fisheries management aiming for more moderate levels of exploitation. The exact level depends on how we weigh different costs and benefits. But some of our data and models can provide valuable input to that discussion.
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Are there any efforts to try to modify those models so they can be used to fine-tune policies?
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It is something we have been advocating, but many of the fisheries biologists who advise these policies are more concerned with the more immediate effects of overexploitation. And policies are often slow to change, so including these evolutionary considerations will probably be a long-term process. In the meantime, we can use these models to create more awareness, also among the public.
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Is there anything consumers can do? Has your research changed the kind of fish you buy?
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Myself, I try to eat more smaller fish like herring, sardines or anchovies, and fewer top predators such as cod, which have to consume many of those smaller fish to grow to the size at which they are usually caught.
\n\n
From the global food production perspective, I think this makes a big difference. In some cultures, people eat a lot of tiny fish, whose mortality is naturally high and therefore less problematic. But in the West, many of us are not used to eating small fish. It is partly just a matter of informing people.
\n\n","field_all_authors":"
By Tim Vernimmen 12.09.2019
\n\n","field_author_bios":"
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Tim Vernimmen is a freelance journalist based near Antwerp, Belgium. He writes about the science of life.
\n
\n\n","field_banner_alt":"Photograph of the deck of a large commercial fishing vessel. Fish are falling from a massive net and piling on the deck floor, as fishermen look on.","field_banner_title":"Freezer trawler","field_caption":"
A freezer trawler hauls in a catch in the Northeast Atlantic. On factory ships such as these, fish are processed and frozen while on board. The largest ships can process several hundred tons of fish a day.
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CREDIT: RIA NOVOSTI / SCIENCE SOURCE
","field_doi":"10.1146/knowable-120919-1","field_headline":" Q&A — Evolutionary biologist Mikko Heino","field_headline_url":{"arguments":["collection","qa"],"type":"client"},"field_is_hero":"1","metatags":{"referrer":"origin","title":"The human hand in fish evolution","description":" Fishery practices that go for the big ones may be counterproductive when mostly the small survive","google_plus_name":"The human hand in fish evolution","og_title":"The human hand in fish evolution","og_site_name":"Knowable Magazine | Annual Reviews","og_type":"article","twitter_cards_type":"summary_large_image","canonical_url":"/article/sustainability/2019/human-hand-fish-evolution","dcterms_description":" Fishery practices that go for the big ones may be counterproductive when mostly the small survive","dcterms_identifier":"10.1146/knowable-120919-1","dcterms_publisher":"Annual Reviews","dcterms_title":"The human hand in fish evolution","dcterms_type":"article","fb_admins":"1642929092406128","google_plus_description":" Fishery practices that go for the big ones may be counterproductive when mostly the small survive","google_plus_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/382/fisheries-evolution-1600x600.jpg?itok=7b4H_gdL","citation_author":"","citation_journal_title":"Knowable Magazine | Annual Reviews","citation_publication_date":"Monday, December 9, 2019 - 07:00","citation_title":"The human hand in fish evolution","article_modified_time":"Monday, December 9, 2019 - 18:29","article_published_time":"Monday, December 9, 2019 - 07:00","og_description":" Fishery practices that go for the big ones may be counterproductive when mostly the small survive","og_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/382/fisheries-evolution-1600x600.jpg?itok=7b4H_gdL","og_image_height":"600","og_image_type":"image/jpeg","og_image_url":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/382/fisheries-evolution-1600x600.jpg?itok=7b4H_gdL","og_image_width":"1600","og_updated_time":"Monday, December 9, 2019 - 18:29","og_url":"/article/sustainability/2019/human-hand-fish-evolution","twitter_cards_description":" Fishery practices that go for the big ones may be counterproductive when mostly the small survive","twitter_cards_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/382/fisheries-evolution-1600x600.jpg?itok=7b4H_gdL","twitter_cards_image_height":"600","twitter_cards_image_width":"1600","twitter_cards_page_url":"/article/sustainability/2019/human-hand-fish-evolution","twitter_cards_site":"@knowablemag","twitter_cards_title":"The human hand in fish evolution","dc_identifier":"10.1146/knowable-120919-1","pocket-site-verification":"665d7e2e5dc1fa27727a154d5c4e80"},"field_primary_author":"By Tim Vernimmen","field_published":"2019-12-09","field_republish_html":"
Q&A — Evolutionary biologist Mikko Heino
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The human hand in fish evolution
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Fishery practices that go for the big ones may be counterproductive when mostly the small survive
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By Tim Vernimmen
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12.9.2019
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Every year, people haul 1 to 3 trillion fish from the ocean. There’s little doubt that this is too many — fish populations have collapsed worldwide. But there’s another thing we are doing to fish: By killing them in such large numbers, we are exerting enormous evolutionary selection pressure. The adaptive changes that result could increase the chance that fish species will survive, but may pose a problem for the people who depend on them.
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By preferentially catching the kind of fish we like — usually big ones — we are inevitably creating a disadvantageous situation for such fish. They’re less likely to survive and reproduce, which reduces the presence of their genes in the next generation. We are, in effect, creating evolutionary pressure for fish to be small. In that way, policies dictating that only large fish should be caught, and small ones left alone, could be counterproductive.
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Mikko Heino, an evolutionary biologist at the University of Bergen in Norway, has spent more than 20 years trying to document and understand how humans are changing the way that fish evolve. Because it’s very hard to directly demonstrate genetic changes due to fishing, he has used a diversity of other approaches, from lab experiments to historical data analysis to computer modeling of long-term evolution.
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As Heino and two coauthors explain in the Annual Review of Ecology, Evolution, and Systematics, there probably is no way for us to catch fish without evolutionary side effects. Yet he believes that taking evolution into account might put an end to well-intended but ill-advised policies and help develop more sustainable ways to manage fisheries.
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This interview has been edited for length and clarity.
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Overfishing is a global issue today, and it seems impossible to inventory all populations to know what exactly is going on. So how do you go about studying the impacts of fisheries?
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First of all, we have learned a lot from studying fisheries where there is a tradition of data collection. In Norway, for example, these data go back almost 90 years, which reflects the very high importance of some of these populations to local economies. Because those catches were naturally fluctuating, there was a desire to better understand where these fluctuations were coming from, because they had such a huge impact on people’s livelihoods.
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By using these kinds of data, we were able to show, for example, that a dramatic collapse of the cod population off the coast of Canada in the late 1980s and early 1990s was preceded by a decrease in the average size of individuals, and earlier reproductive maturation. Follow-up studies have found that similar patterns are affecting dozens of other commercially important fish.
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To really demonstrate evolution, one has to show genetic change. Have you been able to?
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Not yet. All our evidence so far is based on changes in the appearance of the fish, not their genes. I have been involved in a number of projects attempting to show genetic change, but it turns out to be challenging. This partly reflects the highly polygenic nature of traits such as body size and maturation. Almost every gene has an effect on body size, and so does the environment. The selection response is therefore quite spread out across the genome, and not very large at any single gene. Yet the fact that these changes are so common does suggest to me that adaptive evolution is the most likely explanation.
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Another way we are approaching this is by doing experiments in the lab, often using smaller species such as guppies, to show what the evolutionary effects may be when we regularly remove the largest individuals. These experiments are necessarily a simplification of real life, but they may help to focus our attention on aspects we may not have thought about, such as the importance of cannibalism when different generations live in the same place, which is the case in certain populations of cod, for example.
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Last but not least, we can feed the historical and experimental data into computer models to extrapolate our findings into the future and find out what might happen after many generations, or at much larger scales. These are things that would otherwise be too expensive or time-consuming to investigate, and modeling them may help us understand patterns we observe in real life, or even inform new policies and regulations.
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Usually, when human activities are a threat to plants or animals, there is a sense of relief when scientists discover they are evolving in response. So why would it be bad news if fish do the same?
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Well, it depends whether you take the perspective of the fish, or of humans using them as a resource.
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For the fish, it is probably a good thing, as it will make them more resilient to fishing. And from a larger sustainability perspective, that is also good for us. But if you are interested in maintaining the same levels of yield, the problem is that fish are likely to evolve in a way that lowers fisheries’ productivity. So populations and species may still be around, but they will become types that are less valuable for us.
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As human populations keep increasing, this is a problem for food security, perhaps not in Western economies, but in some developing ones, and in many local communities that depend on fisheries.
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That being said, fisheries can also lead fish into a kind of evolutionary trap. Evolution is myopic — it can only respond to changes in the environment, not predict them, so it will reflect the characteristics that were beneficial in the recent past, with no guarantees for the future. But when we push fish to evolve a smaller body size, this may, for example, decrease their physiological ability to make the long spawning migrations that species such as cod and tuna depend on.
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In the review, you point out that even if we don’t fish selectively, so that every individual fish has the same chance of being caught, we are still causing evolution. How so? Is there really no way to avoid this?
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It is essentially unavoidable. When we fish, we impact the circumstances for the population, because we are removing individuals and increasing the rate of mortality. Even if the relative risk of dying is exactly the same for all the fish in the population, irrespective of their traits, if you elevate overall risk — which we always do when we fish — it will cause selection for fish to live faster. This means they will be maturing and reproducing at earlier ages and at smaller sizes, because the ones that wait too long may not get to reproduce at all.
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The only way to minimize selection would be for our fisheries to exactly replace the impact of natural predators, by removing or outcompeting them, as we are arguably doing to some extent. But from a conservation point of view, eliminating large marine predators is also problematic, of course.
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That is not very encouraging. Is there nothing else we can do to minimize our impact?
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The most robust advice I can give is that when fishing for single species, aiming for intermediate-sized fish, or at least not singling out the large ones, is probably the best approach to reduce selection.
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That is almost the opposite of what many fishery practices and regulations currently prescribe, which is to release or avoid small fish and only keep the big ones. Why do these rules exist?
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The classical thinking in fisheries biology goes that we should catch fish when they reach their most productive size, while leaving alive the ones that are still going to grow. Conveniently, this is also fully compatible with the Western desire to eat larger fish. But it is not as sustainable as we like to believe.
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Does this mean that more recent regulations requiring fishing vessels to land everything they catch, even if it can’t be sold — which many fishermen consider to be wasteful — are indeed a good idea?
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They are a move in the right direction, because it makes some selection pressures less strong. But it would be naive to believe that this solves the whole problem. Like I said, a large part of these selective pressures is the result of shortening average lifespans, which is caused by the increased mortality risk. This will still occur if you are harvesting smaller individuals as well, unless you dramatically reduce the harvest of large ones. So lowering the absolute levels of harvesting will also be important.
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This is desirable for many reasons, of course, even without considering the evolutionary perspective. If fish populations are large, you can get a larger catch for the same investment of effort, fuel and salary. So there are good arguments for fisheries management aiming for more moderate levels of exploitation. The exact level depends on how we weigh different costs and benefits. But some of our data and models can provide valuable input to that discussion.
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Are there any efforts to try to modify those models so they can be used to fine-tune policies?
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It is something we have been advocating, but many of the fisheries biologists who advise these policies are more concerned with the more immediate effects of overexploitation. And policies are often slow to change, so including these evolutionary considerations will probably be a long-term process. In the meantime, we can use these models to create more awareness, also among the public.
\n\n
Is there anything consumers can do? Has your research changed the kind of fish you buy?
\n\n
Myself, I try to eat more smaller fish like herring, sardines or anchovies, and fewer top predators such as cod, which have to consume many of those smaller fish to grow to the size at which they are usually caught.
\n\n
From the global food production perspective, I think this makes a big difference. In some cultures, people eat a lot of tiny fish, whose mortality is naturally high and therefore less problematic. But in the West, many of us are not used to eating small fish. It is partly just a matter of informing people.
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10.1146/knowable-120919-1
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Tim Vernimmen is a freelance journalist based near Antwerp, Belgium. He writes about the science of life.
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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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$\"Knowable$
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“Local food” is a term loaded with virtue for many people. Some with environmental concerns lean toward local because food grown nearby requires less energy for transportation. Others find it reassuring to meet a farmer and know where their food comes from and how it was grown.
Others may think of local food as fresher, more nutritious and more likely to be grown organically, or they view “local” as a way to boost local economies and invest in their communities.
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CREDIT: JAMES PROVOST (CC BY-ND)
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Anthropologist David Beriss
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University of New Orleans
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But the very definition of local food is elusive. If it’s about food that was grown nearby, how nearby should that be? Fifty miles away? One hundred? Somewhere within one’s state or country? And for those whose definition of “local” means pride in regional cuisines, does it matter where the ingredients were grown?
Such questions preoccupy David Beriss, an anthropologist at the University of New Orleans focusing on food systems and the author of an article on how people define local food and what it means to them in the 2019 Annual Review of Anthropology.
Knowable Magazine spoke with Beriss about food miles, urban farming, immigrant labor and, of course, red beans and rice. This interview has been edited for length and clarity.
What made you turn to local food as a topic of study?
I got interested in studying food, in part, because of the curious intensity of devotion, here, to the idea of a New Orleans food culture. In 1997, writer-filmmaker Lolis Eric Elie wrote an article in the Times-Picayune about the need to require anybody who purports to cook Louisiana food outside of Louisiana to follow certain culinary rules. I thought he was joking, but then I became friends with him and, turns out, he was not joking at all. He was annoyed by the terrible representations of Louisiana foods elsewhere. And I thought, “Well, that’s odd,” but people really seem to be into that kind of localism.
A few years later, you had people like writers Gary Nabhan and Barbara Kingsolver saying, “I’m going to eat only foods grown within 200 miles of my home” — to make a point that you can do that, even in this age of globalization.
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And that led to another thought. Certain foods here are quintessential New Orleans foods, but they are definitely not, in many respects, local. Red beans and rice is a dish that people eat here on Mondays traditionally. Rice is grown in Louisiana — that could be local, although not in New Orleans, but certainly in Louisiana. The beans, on the other hand, pretty much don’t ever come from Louisiana. But it’s a quintessential New Orleans dish.
So that raised this question: What the heck is local? If a quintessential dish is made of ingredients that are generally not from here, is it still a local dish? That’s what got me into this, thinking about these interesting contradictions.
It seems like you’re talking about a couple of different things: what is physically local and what is culturally local. So is there a single definition of local food?
There isn’t a definitive definition of it. For instance, there’s a famous article by anthropologist Melissa Caldwell about the reception of McDonald’s in Moscow. McDonald’s makes a point of saying that it uses Russian produce, and in this and other ways, the lines are blurred. McDonald’s is clearly not a Russian concept — in fact, it’s a pretty strong symbol of America. Yet it becomes local.
One of the things that I’ve thought about a lot is when you take a foreign ingredient and say, “I want this to be local.” Chefs do this all the time. A chef will say, “I really want to cook with this particular ingredient. It’s not local, so rather than importing it, I’m going to go to a farmer and ask, ‘Will you grow this for me?’ ” When I was in New York, I took a tour at the Italian food market and restaurant Eataly, and they talked about wanting a particular kind of wheat to make their bread. So they went to some farmers in upstate New York and said, “Can you grow this variety of wheat for us? We’ll buy it if you grow it.” And the farmers started growing this variety of wheat that they weren’t growing before. So now it’s local, right?
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A McDonald’s restaurant in Ufa, Russia. The chain, despite its strong US associations, blurs the lines between “foreign” and “local” through promoting its use of Russian produce.
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CREDIT: ROB LEE / FLICKR
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Just recently, there was a debate over what defines something as American. We have cows that are raised in the United States that are then exported to Mexico for butchery, then some parts of the cows are reexported to the United States. At some point it becomes difficult to say, “Is this an American cow or a Mexican cow?” So in terms of “What is local?” it depends on what you are trying to accomplish and what kind of cultural issues you care about. There is no one answer, but it’s a great question.
Even if there is no one definition, in many circles local food has a positive connotation. What emotional and ideological qualities do you think people ascribe to it?
I think what people are really interested in is the local community they create around food. They’re also trying to do something good for a local business when they go to a local food purveyor or shop at a locally owned grocery store instead of shopping at a chain. And they feel like they are helping do something environmentally positive. There is a lot of fuel involved in getting food across the planet, so if you can shorten that distance, you’re helping.
Do you think the positive connotation is warranted?
I think yes, mostly, as long as they’re doing it for the right reasons. You go to the farmers market and you meet people and you create this kind of third space — neither family nor business. It gives you a stronger sense of community, and I think irrespective of what the actual food is, it’s positive.
It can become negative when it incites nationalism and xenophobia. And it can also become arbitrary in some ways. After all, a lot of the wine that I can buy at local wine stores comes from small producers that happen to be in France or Germany, and the only reason these producers can stay in business is because they have this global export.
It also becomes dubious when big corporations project themselves as local or as small businesses when in fact they’re not.
Does the local food movement deal with other issues around food production? Farm labor conditions? Animal welfare? Social justice issues, things like that?
It doesn’t necessarily help with them. Take industrial poultry production. A lot of the chickens that people eat, particularly in the US, are industrially produced and processed in horrible conditions where a lot of the workers are immigrants who are paid poorly and work in abysmal conditions. It’s environmentally bad, it’s bad for the workers, it’s bad for the chickens, it’s bad for the consumers. It’s just bad, except of course for the part about it being cheap — that’s great.
If we ate local, would that be better? I think for the farmers, it’s probably better because you’re buying directly from the person who raised the chickens and they get the money directly. But for other purposes it may not be.
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The popularity of farmers markets is on the rise in the US, partly fueled by consumer desire to buy food grown close to home. (Numbers shown are only for markets that were voluntarily reported to the USDA’s Agricultural Marketing Service.)
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If we want to solve the problems that the workers confront, like dangerous working conditions and bad wages, maybe the way to address those is directly. Can they work without getting their hands cut off? Can they support their families? I don’t know if localness is really an answer to those questions. It doesn’t seem like it is.
Is it better to buy something local that was produced in a more conventional way or something that’s organic that was produced farther away?
It’s really hard to weigh in on environmental questions like this. Is it better for me to buy meat from the farmers market that’s raised nearby in a conventional way, or is it better for me to buy meat from halfway across the world that’s raised in a free range, grass-fed manner?
There’s a lot of what writer Michael Pollan calls “industrial organic” out there. And the workers working on those organic farms don’t necessarily have better conditions or better pay than workers working on conventional farms.
As food production becomes more automated — drone farming, robots picking strawberries — how do you think technology will affect local food?
We certainly have a lot more automation in agriculture today than we did even 10 to 15 years ago. Adding to that, one of the ways that people have written about making food more local is an industrialization of food production in cities: interior farms inside of factories. And then there’s rooftop gardening and urban farming; those things are already happening. It’s a new kind of farming right in the middle of the city and that certainly seems local. I have no idea if technology makes things more or less “local” in people’s minds. If it’s just a question of distance, it doesn’t matter if it’s a drone or me that’s picking it, right?
What do you think the future holds? Do you think local food will continue to be a trend or will people move on to some other thing?
I have at least two hypotheses. First, it probably is, at least partly, a question of fashion. People use food for the purpose of social distinction, and local food has in many ways replaced exotic imported food for purposes of showing off one’s knowledge, taste and sophistication. In the US, for instance, rather than ordering an imported beer, now we try to aim for the hyper-local to demonstrate that we know what is good. There are many examples of fashionable trends that recede whenever the next fashion appears.
But second, there are underlying issues around globalization, sustainability, community and justice that local food may help people address. Even if the fashion for sophisticated people to show off their knowledge of local food passes, it is possible that some kind of deeper set of structures around urban farming or local craft production will become more important as we try to deal with those issues.
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\n \n \n \n By\n\n \n Stephanie Parker\n \n \n \n \n 02.26.2020\n
\n","field_ar_article":{"arguments":[]},"field_author_bios":"
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Stephanie Parker is a freelance writer and photographer living in Switzerland, where her favorite local food is definitely cheese. You can follow her on twitter @sparkersays and see more of her work at www.stephaniedparker.com.
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\n","field_banner_alt":"Photograph of a vegetable stall. A vendor is receiving money from a customer while other shoppers mill about.","field_banner_title":"Farmers market","field_caption":"
Farmers markets, such as this one in Queens, New York, are increasingly popular as consumers look to purchase “local” foods.
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CREDIT: USDA PHOTO BY PRESTON KERES
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Q&A — Anthropologist David Beriss
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What makes food ‘local’?
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More people are choosing what to eat based on where it was grown, made or created. An anthropologist looks at the myriad ways we link food to place — and whether it really could make a difference.
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\n By Stephanie Parker \n \n
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2.26.2020
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“Local food” is a term loaded with virtue for many people. Some with environmental concerns lean toward local because food grown nearby requires less energy for transportation. Others find it reassuring to meet a farmer and know where their food comes from and how it was grown.
Others may think of local food as fresher, more nutritious and more likely to be grown organically, or they view “local” as a way to boost local economies and invest in their communities.
But the very definition of local food is elusive. If it’s about food that was grown nearby, how nearby should that be? Fifty miles away? One hundred? Somewhere within one’s state or country? And for those whose definition of “local” means pride in regional cuisines, does it matter where the ingredients were grown?
Such questions preoccupy David Beriss, an anthropologist at the University of New Orleans focusing on food systems and the author of an article on how people define local food and what it means to them in the 2019 Annual Review of Anthropology.
Knowable Magazine spoke with Beriss about food miles, urban farming, immigrant labor and, of course, red beans and rice. This interview has been edited for length and clarity.
What made you turn to local food as a topic of study?
I got interested in studying food, in part, because of the curious intensity of devotion, here, to the idea of a New Orleans food culture. In 1997, writer-filmmaker Lolis Eric Elie wrote an article in the Times-Picayune about the need to require anybody who purports to cook Louisiana food outside of Louisiana to follow certain culinary rules. I thought he was joking, but then I became friends with him and, turns out, he was not joking at all. He was annoyed by the terrible representations of Louisiana foods elsewhere. And I thought, “Well, that’s odd,” but people really seem to be into that kind of localism.
A few years later, you had people like writers Gary Nabhan and Barbara Kingsolver saying, “I’m going to eat only foods grown within 200 miles of my home” — to make a point that you can do that, even in this age of globalization.
And that led to another thought. Certain foods here are quintessential New Orleans foods, but they are definitely not, in many respects, local. Red beans and rice is a dish that people eat here on Mondays traditionally. Rice is grown in Louisiana — that could be local, although not in New Orleans, but certainly in Louisiana. The beans, on the other hand, pretty much don’t ever come from Louisiana. But it’s a quintessential New Orleans dish.
So that raised this question: What the heck is local? If a quintessential dish is made of ingredients that are generally not from here, is it still a local dish? That’s what got me into this, thinking about these interesting contradictions.
It seems like you’re talking about a couple of different things: what is physically local and what is culturally local. So is there a single definition of local food?
There isn’t a definitive definition of it. For instance, there’s a famous article by anthropologist Melissa Caldwell about the reception of McDonald’s in Moscow. McDonald’s makes a point of saying that it uses Russian produce, and in this and other ways, the lines are blurred. McDonald’s is clearly not a Russian concept — in fact, it’s a pretty strong symbol of America. Yet it becomes local.
One of the things that I’ve thought about a lot is when you take a foreign ingredient and say, “I want this to be local.” Chefs do this all the time. A chef will say, “I really want to cook with this particular ingredient. It’s not local, so rather than importing it, I’m going to go to a farmer and ask, ‘Will you grow this for me?’ ” When I was in New York, I took a tour at the Italian food market and restaurant Eataly, and they talked about wanting a particular kind of wheat to make their bread. So they went to some farmers in upstate New York and said, “Can you grow this variety of wheat for us? We’ll buy it if you grow it.” And the farmers started growing this variety of wheat that they weren’t growing before. So now it’s local, right?
Just recently, there was a debate over what defines something as American. We have cows that are raised in the United States that are then exported to Mexico for butchery, then some parts of the cows are reexported to the United States. At some point it becomes difficult to say, “Is this an American cow or a Mexican cow?” So in terms of “What is local?” it depends on what you are trying to accomplish and what kind of cultural issues you care about. There is no one answer, but it’s a great question.
Even if there is no one definition, in many circles local food has a positive connotation. What emotional and ideological qualities do you think people ascribe to it?
I think what people are really interested in is the local community they create around food. They’re also trying to do something good for a local business when they go to a local food purveyor or shop at a locally owned grocery store instead of shopping at a chain. And they feel like they are helping do something environmentally positive. There is a lot of fuel involved in getting food across the planet, so if you can shorten that distance, you’re helping.
Do you think the positive connotation is warranted?
I think yes, mostly, as long as they’re doing it for the right reasons. You go to the farmers market and you meet people and you create this kind of third space — neither family nor business. It gives you a stronger sense of community, and I think irrespective of what the actual food is, it’s positive.
It can become negative when it incites nationalism and xenophobia. And it can also become arbitrary in some ways. After all, a lot of the wine that I can buy at local wine stores comes from small producers that happen to be in France or Germany, and the only reason these producers can stay in business is because they have this global export.
It also becomes dubious when big corporations project themselves as local or as small businesses when in fact they’re not.
Does the local food movement deal with other issues around food production? Farm labor conditions? Animal welfare? Social justice issues, things like that?
It doesn’t necessarily help with them. Take industrial poultry production. A lot of the chickens that people eat, particularly in the US, are industrially produced and processed in horrible conditions where a lot of the workers are immigrants who are paid poorly and work in abysmal conditions. It’s environmentally bad, it’s bad for the workers, it’s bad for the chickens, it’s bad for the consumers. It’s just bad, except of course for the part about it being cheap — that’s great.
If we ate local, would that be better? I think for the farmers, it’s probably better because you’re buying directly from the person who raised the chickens and they get the money directly. But for other purposes it may not be.
If we want to solve the problems that the workers confront, like dangerous working conditions and bad wages, maybe the way to address those is directly. Can they work without getting their hands cut off? Can they support their families? I don’t know if localness is really an answer to those questions. It doesn’t seem like it is.
Is it better to buy something local that was produced in a more conventional way or something that’s organic that was produced farther away?
It’s really hard to weigh in on environmental questions like this. Is it better for me to buy meat from the farmers market that’s raised nearby in a conventional way, or is it better for me to buy meat from halfway across the world that’s raised in a free range, grass-fed manner?
There’s a lot of what writer Michael Pollan calls “industrial organic” out there. And the workers working on those organic farms don’t necessarily have better conditions or better pay than workers working on conventional farms.
As food production becomes more automated — drone farming, robots picking strawberries — how do you think technology will affect local food?
We certainly have a lot more automation in agriculture today than we did even 10 to 15 years ago. Adding to that, one of the ways that people have written about making food more local is an industrialization of food production in cities: interior farms inside of factories. And then there’s rooftop gardening and urban farming; those things are already happening. It’s a new kind of farming right in the middle of the city and that certainly seems local. I have no idea if technology makes things more or less “local” in people’s minds. If it’s just a question of distance, it doesn’t matter if it’s a drone or me that’s picking it, right?
What do you think the future holds? Do you think local food will continue to be a trend or will people move on to some other thing?
I have at least two hypotheses. First, it probably is, at least partly, a question of fashion. People use food for the purpose of social distinction, and local food has in many ways replaced exotic imported food for purposes of showing off one’s knowledge, taste and sophistication. In the US, for instance, rather than ordering an imported beer, now we try to aim for the hyper-local to demonstrate that we know what is good. There are many examples of fashionable trends that recede whenever the next fashion appears.
But second, there are underlying issues around globalization, sustainability, community and justice that local food may help people address. Even if the fashion for sophisticated people to show off their knowledge of local food passes, it is possible that some kind of deeper set of structures around urban farming or local craft production will become more important as we try to deal with those issues.
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10.1146/knowable-022420-1
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Stephanie Parker is a freelance writer and photographer living in Switzerland, where her favorite local food is definitely cheese. You can follow her on twitter @sparkersays and see more of her work at www.stephaniedparker.com.
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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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You hear a mechanical buzz. You look up, and there it is, hovering in the sky — four whirring rotors. Over your shoulder, you catch sight of someone tracking the flight and manipulating controls.
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CREDIT: JAMES PROVOST (CC BY-ND)
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Roboticist Sarah Tang
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Nuro, Inc., Mountain View, California
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Drones, little flying vehicles with varying states of autonomy, have arrived. Some survey crops from above. Some film dazzling videos. Some just annoy the neighbors. In Virginia, drones have delivered library books. And when NASA launches the Mars 2020 rover in a few weeks, it will feature a helicopter that will have to be somewhat autonomous because of the communication delay between Earth and Mars.
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Drones have come far in recent years, says roboticist Sarah Tang, who studied drones and unmanned aerial vehicles (UAVs) — a more comprehensive term for autonomous flyers — for her PhD work at the University of Pennsylvania. But though the machinery and software have both seen strides, work remains before drones will be as useful as many hope, as Tang and her former doctoral adviser Vijay Kumar describe in the Annual Review of Control, Robotics and Autonomous Systems.
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Knowable Magazine asked Tang, now a software engineer working on self-driving cars at Nuro in Mountain View, California, about the promise and the challenges. This conversation has been edited for length and clarity.
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What got you interested in studying robotics and drones?
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Explore Knowable’s coronavirus coverage
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At Princeton, in my junior year, I did an independent project on coordinating underwater robots to synchronize their movements. I got really interested in teams of robots working together and how they can collaborate, communicate and coordinate.
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I began working with drones at UPenn. They have this great capability for very agile maneuvers. And that was a really interesting problem from a planning and control standpoint: On the one hand, you have this vehicle that’s very hard to control and stabilize, and on the other, you have to plan very quickly to move past obstacles on the fly — you have to get it to do all these acrobatic things. I thought those two things together were really cool.
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What’s the difference between a drone and an unmanned aerial vehicle?
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Drone refers to the platform itself, a flying thing. UAV refers to any flying platform that is not piloted by a person — there’s software controlling it.
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In this video from Alphabet, Inc.’s Wing project, a librarian working for the Montgomery County Public School in Virginia discusses using drones to deliver books to students. Along with library deliveries, the drones also deliver coffee, FedEx packages, prescriptions and more in Montgomery County. Wing is one of the first high-profile deployments of drone delivery. According to the company’s website, Virginia is the only place in the US where it is operating. Wing also has operations in Canberra, Australia and Helsinki, Finland. Companies such as Amazon, Postmates and 7-Eleven also have dabbled in drone delivery, with bigger plans for the future.
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CREDIT: WING
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What are some of the most common misconceptions about these vehicles?
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Mostly they’re about what the drones are capable of doing on their own. Part of that comes from the research videos: People show robots doing these intricate, acrobatic things. But what viewers might not realize is that the robots were dependent on external systems. They had markers on them. Think motion-capture technology, like what was done with the character Gollum in The Lord of the Rings: Actor Andy Serkis wore a suit with balls all over it — markers — to guide the animation. We put those same things on our robots.
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Based on the markers, an external camera system detects, with centimeter accuracy, where each robot is spatially, how fast it is moving, and its orientation. That is very, very far from a fully autonomous system that is using only its own sensors to map and understand the world and where it is.
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A lot of the current work is thinking about fully autonomous vehicles that can do things like food deliveries or surveillance. There’s still a lot of work to be done there, in terms of getting the autonomy onboard so the vehicles can navigate without external help.
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What are the some of the sensors that go into a more successful unmanned aerial vehicle?
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There are two big fields. If you have a robot that’s designed for something like mine inspection, the robot doesn’t have to be quite as acrobatic, so it can carry more sensors. It will usually have a LIDAR system [a laser scanning system that helps build 3D maps of the world] and cameras. Something like a video drone, which requires less precision in its flight path, will typically have only a camera, which will keep it light and agile.
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How are people are using drones and/or UAVs?
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Right now, most of it is just in the hobbyist space. Some companies, like DJI and Skydio are huge for people who are into videography. This could extend to filmmaking and other video projects.
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On the commercial side, there are quite a few applications that are being explored. Insurance companies use them for roof inspection, bridge inspection or cell-tower inspections. Things that would be very expensive if you needed to get a human to climb into those spaces — places like mines and tunnels.
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Another application is reconstruction of buildings: Real-estate companies use drones to fly around and make 3D models of houses and buildings. In agriculture, there’s this idea of using drones to fly over and inspect crops. Entertainment is another big one, with light shows like the 2018 Winter Olympics opening ceremonies and the Lady Gaga Super Bowl halftime show using drones the year before. And of course, there’s drone delivery.
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There are different designs depending on the use — the helicopter-like rotor ones and fixed-wing robots. In the research space, there are also bio-inspired robots with flexible wings that fly like birds or look like dragonflies.
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What drives the bio-inspired research? Is it about trying to figure out things like how insects fly, or is it oriented toward finding new ways to fly?
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I think one of the big motivations is trying to figure out how to make these robots smaller. Researchers look at insects and the way that they fly to try to figure out what form their drones can take so that they can have all the sensors and motors they need but be as small as possible.
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The Robobee from Harvard’s Wyss Institute is one of a handful of animal-inspired drones. Potential uses include surveillance, search and rescue missions, monitoring the weather and other environmental conditions, and to help pollinate crops.
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CREDIT: WYSS INSTITUTE AT HARVARD UNIVERSITY
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What is the advantage of being small?
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One idea is that you could use a “swarm” of drones to do a task, like a coordinated light show or a search-and-rescue operation. And when you have more drones, obviously you need to scale down the size of them. On the research side, it is mostly driven by the possibility of creating cooperative teams. Companies like Intel are working on swarms of larger drones for entertainment.
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What has driven the growth of aerial vehicles?
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There was a huge push in the research community to use them as a platform for robotics applications, because they were being mass-produced for recreational uses, and became cheap. You can buy them off the shelf, set up the hardware and run experiments with them.
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Later, the research field started to see the autonomous capabilities they could have. This led to startup companies that proposed offering services, with funding from venture capitalists and other sources.
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Another big push came from DARPA [Defense Advanced Research Projects Agency, the US Department of Defense’s technology research agency]. Historically, DARPA’s been interested in robotics and autonomy, and its Fast Lightweight Autonomy program promotes development of autonomous vehicles using limited sensors and battery. They had to be built with commercial parts and there was a weight limit as well. They had to be able to operate autonomously with no GPS, no prebuilt maps and no pilot intervention.
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For the task, it would be given the position of a red barrel. The drone would know what the barrel looked like beforehand. It would have to fly to that position, identify the red barrel and then fly back. But along the way, it would have to do all sorts of things: It might start outdoors and have to fly through a window to get indoors, then go down the stairs of the building and come back out a door to fly back to its starting position.
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The idea was that the robot would have no idea what could be between itself and this red barrel’s location, and would have to be able to sense and map and make decisions in real time to navigate these previously unknown environments. There was also an emphasis placed on speed: They really wanted to push the speed at which these robots would be able to fly.
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The Department of Defense is interested in surveillance and mapping applications, and previously had a humanoid disaster-response challenges and an urban driverless vehicle challenge that both involved autonomous systems. The funding that it provided really pushed the research forward.
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A drone participates in DARPA’s Fast Lightweight Autonomy program, which is intended to speed up drone development. DARPA (the Defense Advanced Research Projects Agency) is interested in military, surveillance and search-and-rescue applications.
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CREDIT: DARPA TV
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What kind of dead ends have there been?
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There was a period of disillusionment after all the startup funding. There were some pretty high-profile duds. For example, a company called Torquing Group got $3 million from a Kickstarter campaign for a drone called Zano and it never delivered a product. A company called Lily Robotics also folded before delivering a product; it did a crowdfunding campaign for a drone that would follow you, but had to close before it was able to ship the product. GoPro made a drone called the Karma. Users reported that it had an issue where it would just randomly fall out of the sky. GoPro ended up recalling the product and stopping production altogether.
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People began to realize that this problem is harder than we initially thought. It’s not something that a couple million dollars and implementing ideas from research papers can solve. Being able to solve the manufacturing problem, solve the robotics and autonomy problem, and then put it all together into a product that you deliver to a customer is really challenging and difficult. Funders are a bit more selective now.
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What does it take to keep a UAV stabilized in flight?
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If you think about a drone with four rotors — a quadrotor — this is not something that can stabilize itself. If you buy one off the shelf, there’s software running on board to stabilize it for you, and then you control where it goes. The ability to hover in place is complex. The robot needs to know its orientation and its speed. It also needs to control the rate at which each of its motors spin to stay in balance. That all requires software.
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A drone must make decisions in order to safely navigate its environment. On the left is an example of an outdoor environment a drone might need to fly through; on the right is an indoor environment. Blue lines represent suitable flight paths from the drone’s starting position to the intended destinations (visible as red points on the right). Sensors, including cameras, on the drone provide input that helps the software autonomously navigate the environment while staying stable in flight. Early navigation successes have helped with the development of ways to further interact with an environment, such as grasping objects.
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Your review paper covers a lot of the software needs of drone systems. One of the topics covered is artificial intelligence systems, including Kalman filtering. Can you explain what this is and how it connects to UAV systems?
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A Kalman filter is a mathematical model that provides a way for a robot to fuse information that comes from its sensors with its internal model of how it expects to be moving. One often-used example is to picture a robot that is moving down a hallway. It knows how many doors this hallway has, and it knows a door is every 2 meters.
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If it measures velocity and time, it can estimate distance. That’s one mode of information. And the other mode is, “Do you see a door or not?” Say the robot thinks that it’s gone 2.5 meters, and then suddenly it sees a door. It expected the first door to be at 2 meters, so it has to take these two pieces of information and resolve them to come up with a belief of where it is in the world.
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The Kalman filter allows robots to combine information over time from multiple sensors to understand where they are in the world. Most importantly, it allows us to model noise in the robot’s measurements and understand how certain or uncertain the robot should be.
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You also talk about iterative learning control in your article. What is that?
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One of the coolest things that’s happening is the possibility of using machine learning and deep learning to better control robots. For example, you don’t have an exact model of how your motors will respond to a command or disturbances from the wind or other things around you. In iterative learning, as you keep performing the task, you use that information to improve your model of the world.
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Let’s say I want my drone to fly in a certain shape, like a circle. If I feed the robot a sequence of input, like rotor commands, then it’s going to follow the circle. I observe what the robot actually does and what I wanted it to do. Based on its errors, I calculate the corrections to apply to the input to improve performance the next time.
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How have advancements in machine learning affected UAVs?
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It’s helped with understanding the sensor data that the UAV is getting. The robot might have a suite of six or eight cameras, and it’s getting all this imagery data. Machine learning can help us process that into information about the world that the robot can use, such as how fast it’s moving. That’s one area.
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The other is controls. You can use machine learning to improve how well your robot can fly while compensating for things like wind that are hard to model mathematically.
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What do you see happening for UAVs in the next few years?
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On the research side, there’s more to be done in terms of fully autonomous operation and demonstrating that that can be done robustly. For example, Skydio has this drone that can track and follow you while you’re driving or mountain biking or riding a horse. That’s been a huge advancement.
\n\n
Another is working with regulators to prove that these things are safe to fly autonomously outside of line-of-sight and over cities and populations. We also need to be able to make that jump from testing within line-of-sight to having some sort of pilot program where a company says, “OK, we’re going to start doing deliveries with these,” and then launch a service that makes money. I think that’s really exciting for the future.
\n\n
What have the more successful drone researchers or drone startups done to excel in this space?
\n\n
This is a personal opinion, but I think just having some experience in robotics and having the perspective that there are challenges, that things take a while. That’s the differentiating factor, especially for companies. Don’t overpromise. Don’t say, “Give me $100 and I’ll deliver a drone to you in four months that I haven’t even started developing yet.” Take things one step at a time and do this systematically.
\n\n
For drones, what holds the most promise right now?
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I think inspection is what resonates the most: using robots to inspect under bridges or on top of roofs or in other hazardous places.
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I’m a little bit wary about personal robotics. If you take a robot and you put it in consumers’ hands and say, “You can interact with this robot however you want,” the needs for how well this robot has to function and the situations that this robot has to understand and handle are just endless.
\n\n
But if you have a defined operational area, you can say, “This is my task and I need to be very robust and very reliable within this task.” This narrows down your problem to something manageable. You can focus on the autonomy features that you need to get that working very, very well.
\n\n","field_all_authors":"
By John Wenz 07.23.2020
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John Wenz is digital producer at Knowable Magazine.
\n
\n\n","field_banner_alt":"A flying drone with eight rotors flies as three blurry people in the background look on.","field_banner_title":"A drone!","field_caption":"
The SteadiDrone EI8GHT Octocopter takes a test flight. Many drones are in use or in development, some of them autonomous and others human-controlled. Used recreationally for decades, the technology has advanced by leaps and bounds and drones are being deployed, tested and envisioned for an array of applications.
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CREDIT: MARTIN DIVISEK / BLOOMBERG VIA GETTY IMAGES
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Q&A — Roboticist Sarah Tang
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Less toy, more workhorse: Drones get functional
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Airborne autonomous vehicles could soon be dropping off your Amazon packages, delivering your food and even ensuring that the infrastructure around you is safe and sound
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By John Wenz
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7.23.2020
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You hear a mechanical buzz. You look up, and there it is, hovering in the sky — four whirring rotors. Over your shoulder, you catch sight of someone tracking the flight and manipulating controls.
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Drones, little flying vehicles with varying states of autonomy, have arrived. Some survey crops from above. Some film dazzling videos. Some just annoy the neighbors. In Virginia, drones have delivered library books. And when NASA launches the Mars 2020 rover in a few weeks, it will feature a helicopter that will have to be somewhat autonomous because of the communication delay between Earth and Mars.
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Drones have come far in recent years, says roboticist Sarah Tang, who studied drones and unmanned aerial vehicles (UAVs) — a more comprehensive term for autonomous flyers — for her PhD work at the University of Pennsylvania. But though the machinery and software have both seen strides, work remains before drones will be as useful as many hope, as Tang and her former doctoral adviser Vijay Kumar describe in the Annual Review of Control, Robotics and Autonomous Systems.
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Knowable Magazine asked Tang, now a software engineer working on self-driving cars at Nuro in Mountain View, California, about the promise and the challenges. This conversation has been edited for length and clarity.
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What got you interested in studying robotics and drones?
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Explore Knowable’s coronavirus coverage
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At Princeton, in my junior year, I did an independent project on coordinating underwater robots to synchronize their movements. I got really interested in teams of robots working together and how they can collaborate, communicate and coordinate.
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I began working with drones at UPenn. They have this great capability for very agile maneuvers. And that was a really interesting problem from a planning and control standpoint: On the one hand, you have this vehicle that’s very hard to control and stabilize, and on the other, you have to plan very quickly to move past obstacles on the fly — you have to get it to do all these acrobatic things. I thought those two things together were really cool.
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What’s the difference between a drone and an unmanned aerial vehicle?
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Drone refers to the platform itself, a flying thing. UAV refers to any flying platform that is not piloted by a person — there’s software controlling it.
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What are some of the most common misconceptions about these vehicles?
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Mostly they’re about what the drones are capable of doing on their own. Part of that comes from the research videos: People show robots doing these intricate, acrobatic things. But what viewers might not realize is that the robots were dependent on external systems. They had markers on them. Think motion-capture technology, like what was done with the character Gollum in The Lord of the Rings: Actor Andy Serkis wore a suit with balls all over it — markers — to guide the animation. We put those same things on our robots.
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Based on the markers, an external camera system detects, with centimeter accuracy, where each robot is spatially, how fast it is moving, and its orientation. That is very, very far from a fully autonomous system that is using only its own sensors to map and understand the world and where it is.
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A lot of the current work is thinking about fully autonomous vehicles that can do things like food deliveries or surveillance. There’s still a lot of work to be done there, in terms of getting the autonomy onboard so the vehicles can navigate without external help.
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What are the some of the sensors that go into a more successful unmanned aerial vehicle?
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There are two big fields. If you have a robot that’s designed for something like mine inspection, the robot doesn’t have to be quite as acrobatic, so it can carry more sensors. It will usually have a LIDAR system [a laser scanning system that helps build 3D maps of the world] and cameras. Something like a video drone, which requires less precision in its flight path, will typically have only a camera, which will keep it light and agile.
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How are people are using drones and/or UAVs?
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Right now, most of it is just in the hobbyist space. Some companies, like DJI and Skydio are huge for people who are into videography. This could extend to filmmaking and other video projects.
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On the commercial side, there are quite a few applications that are being explored. Insurance companies use them for roof inspection, bridge inspection or cell-tower inspections. Things that would be very expensive if you needed to get a human to climb into those spaces — places like mines and tunnels.
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Another application is reconstruction of buildings: Real-estate companies use drones to fly around and make 3D models of houses and buildings. In agriculture, there’s this idea of using drones to fly over and inspect crops. Entertainment is another big one, with light shows like the 2018 Winter Olympics opening ceremonies and the Lady Gaga Super Bowl halftime show using drones the year before. And of course, there’s drone delivery.
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There are different designs depending on the use — the helicopter-like rotor ones and fixed-wing robots. In the research space, there are also bio-inspired robots with flexible wings that fly like birds or look like dragonflies.
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What drives the bio-inspired research? Is it about trying to figure out things like how insects fly, or is it oriented toward finding new ways to fly?
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I think one of the big motivations is trying to figure out how to make these robots smaller. Researchers look at insects and the way that they fly to try to figure out what form their drones can take so that they can have all the sensors and motors they need but be as small as possible.
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What is the advantage of being small?
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One idea is that you could use a “swarm” of drones to do a task, like a coordinated light show or a search-and-rescue operation. And when you have more drones, obviously you need to scale down the size of them. On the research side, it is mostly driven by the possibility of creating cooperative teams. Companies like Intel are working on swarms of larger drones for entertainment.
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What has driven the growth of aerial vehicles?
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There was a huge push in the research community to use them as a platform for robotics applications, because they were being mass-produced for recreational uses, and became cheap. You can buy them off the shelf, set up the hardware and run experiments with them.
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Later, the research field started to see the autonomous capabilities they could have. This led to startup companies that proposed offering services, with funding from venture capitalists and other sources.
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Another big push came from DARPA [Defense Advanced Research Projects Agency, the US Department of Defense’s technology research agency]. Historically, DARPA’s been interested in robotics and autonomy, and its Fast Lightweight Autonomy program promotes development of autonomous vehicles using limited sensors and battery. They had to be built with commercial parts and there was a weight limit as well. They had to be able to operate autonomously with no GPS, no prebuilt maps and no pilot intervention.
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For the task, it would be given the position of a red barrel. The drone would know what the barrel looked like beforehand. It would have to fly to that position, identify the red barrel and then fly back. But along the way, it would have to do all sorts of things: It might start outdoors and have to fly through a window to get indoors, then go down the stairs of the building and come back out a door to fly back to its starting position.
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The idea was that the robot would have no idea what could be between itself and this red barrel’s location, and would have to be able to sense and map and make decisions in real time to navigate these previously unknown environments. There was also an emphasis placed on speed: They really wanted to push the speed at which these robots would be able to fly.
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The Department of Defense is interested in surveillance and mapping applications, and previously had a humanoid disaster-response challenges and an urban driverless vehicle challenge that both involved autonomous systems. The funding that it provided really pushed the research forward.
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What kind of dead ends have there been?
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There was a period of disillusionment after all the startup funding. There were some pretty high-profile duds. For example, a company called Torquing Group got $3 million from a Kickstarter campaign for a drone called Zano and it never delivered a product. A company called Lily Robotics also folded before delivering a product; it did a crowdfunding campaign for a drone that would follow you, but had to close before it was able to ship the product. GoPro made a drone called the Karma. Users reported that it had an issue where it would just randomly fall out of the sky. GoPro ended up recalling the product and stopping production altogether.
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People began to realize that this problem is harder than we initially thought. It’s not something that a couple million dollars and implementing ideas from research papers can solve. Being able to solve the manufacturing problem, solve the robotics and autonomy problem, and then put it all together into a product that you deliver to a customer is really challenging and difficult. Funders are a bit more selective now.
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What does it take to keep a UAV stabilized in flight?
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If you think about a drone with four rotors — a quadrotor — this is not something that can stabilize itself. If you buy one off the shelf, there’s software running on board to stabilize it for you, and then you control where it goes. The ability to hover in place is complex. The robot needs to know its orientation and its speed. It also needs to control the rate at which each of its motors spin to stay in balance. That all requires software.
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Your review paper covers a lot of the software needs of drone systems. One of the topics covered is artificial intelligence systems, including Kalman filtering. Can you explain what this is and how it connects to UAV systems?
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A Kalman filter is a mathematical model that provides a way for a robot to fuse information that comes from its sensors with its internal model of how it expects to be moving. One often-used example is to picture a robot that is moving down a hallway. It knows how many doors this hallway has, and it knows a door is every 2 meters.
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If it measures velocity and time, it can estimate distance. That’s one mode of information. And the other mode is, “Do you see a door or not?” Say the robot thinks that it’s gone 2.5 meters, and then suddenly it sees a door. It expected the first door to be at 2 meters, so it has to take these two pieces of information and resolve them to come up with a belief of where it is in the world.
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The Kalman filter allows robots to combine information over time from multiple sensors to understand where they are in the world. Most importantly, it allows us to model noise in the robot’s measurements and understand how certain or uncertain the robot should be.
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You also talk about iterative learning control in your article. What is that?
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One of the coolest things that’s happening is the possibility of using machine learning and deep learning to better control robots. For example, you don’t have an exact model of how your motors will respond to a command or disturbances from the wind or other things around you. In iterative learning, as you keep performing the task, you use that information to improve your model of the world.
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Let’s say I want my drone to fly in a certain shape, like a circle. If I feed the robot a sequence of input, like rotor commands, then it’s going to follow the circle. I observe what the robot actually does and what I wanted it to do. Based on its errors, I calculate the corrections to apply to the input to improve performance the next time.
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How have advancements in machine learning affected UAVs?
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It’s helped with understanding the sensor data that the UAV is getting. The robot might have a suite of six or eight cameras, and it’s getting all this imagery data. Machine learning can help us process that into information about the world that the robot can use, such as how fast it’s moving. That’s one area.
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The other is controls. You can use machine learning to improve how well your robot can fly while compensating for things like wind that are hard to model mathematically.
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What do you see happening for UAVs in the next few years?
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On the research side, there’s more to be done in terms of fully autonomous operation and demonstrating that that can be done robustly. For example, Skydio has this drone that can track and follow you while you’re driving or mountain biking or riding a horse. That’s been a huge advancement.
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Another is working with regulators to prove that these things are safe to fly autonomously outside of line-of-sight and over cities and populations. We also need to be able to make that jump from testing within line-of-sight to having some sort of pilot program where a company says, “OK, we’re going to start doing deliveries with these,” and then launch a service that makes money. I think that’s really exciting for the future.
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What have the more successful drone researchers or drone startups done to excel in this space?
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This is a personal opinion, but I think just having some experience in robotics and having the perspective that there are challenges, that things take a while. That’s the differentiating factor, especially for companies. Don’t overpromise. Don’t say, “Give me $100 and I’ll deliver a drone to you in four months that I haven’t even started developing yet.” Take things one step at a time and do this systematically.
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For drones, what holds the most promise right now?
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I think inspection is what resonates the most: using robots to inspect under bridges or on top of roofs or in other hazardous places.
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I’m a little bit wary about personal robotics. If you take a robot and you put it in consumers’ hands and say, “You can interact with this robot however you want,” the needs for how well this robot has to function and the situations that this robot has to understand and handle are just endless.
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But if you have a defined operational area, you can say, “This is my task and I need to be very robust and very reliable within this task.” This narrows down your problem to something manageable. You can focus on the autonomy features that you need to get that working very, very well.
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10.1146/knowable-072220-1
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John Wenz is digital producer at Knowable Magazine.
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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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The snapshots above look like people you’d know. Your daughter’s best friend from college, maybe? That guy from human resources at work? The emergency-room doctor who took care of your sprained ankle? One of the kids from down the street?
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Nope. All of these images are “deepfakes” — the nickname for computer-generated, photorealistic media created via cutting-edge artificial intelligence technology. They are just one example of what this fast-evolving method can do. (You could create synthetic images yourself at ThisPersonDoesNotExist.com.) Hobbyists, for example, have used the same AI techniques to populate YouTube with a host of startlingly lifelike video spoofs — the kind that show real people such as Barack Obama or Vladimir Putin doing or saying goofy things they never did or said, or that revise famous movie scenes to give actors like Amy Adams or Sharon Stone the face of Nicolas Cage. All the hobbyists need is a PC with a high-end graphics chip, and maybe 48 hours of processing time.
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It’s good fun, not to mention jaw-droppingly impressive. And coming down the line are some equally remarkable applications that could make quick work out of once-painstaking tasks: filling in gaps and scratches in damaged images or video; turning satellite photos into maps; creating realistic streetscape videos to train autonomous vehicles; giving a natural-sounding voice to those who have lost their own; turning Hollywood actors into their older or younger selves; and much more.
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Deepfake artificial-intelligence methods can map the face of, say, actor Nicolas Cage onto anyone else — in this case, actor Amy Adams in the film Man of Steel.
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CREDIT: MEMES COFFEE
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Yet this technology has an obvious — and potentially enormous — dark side. Witness the many denunciations of deepfakes as a menace, Facebook’s decision in January to ban (some) deepfakes outright and Twitter’s announcement a month later that it would follow suit.
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“Deepfakes play to our weaknesses,” explains Jennifer Kavanagh, a political scientist at the RAND Corporation and coauthor of “Truth Decay,” a 2018 RAND report about the diminishing role of facts and data in public discourse. When we see a doctored video that looks utterly real, she says, “it’s really hard for our brains to disentangle whether that’s true or false.” And the internet being what it is, there are any number of online scammers, partisan zealots, state-sponsored hackers and other bad actors eager to take advantage of that fact.
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“The threat here is not, ‘Oh, we have fake content!’” says Hany Farid, a computer scientist at the University of California, Berkeley, and author of an overview of image forensics in the 2019 Annual Review of Vision Science. Media manipulation has been around forever. “The threat is the democratization of Hollywood-style technology that can create really compelling fake content.” It’s photorealism that requires no skill or effort, he says, coupled with a social-media ecosystem that can spread that content around the world with a mouse click.
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Digital image forensics expert Hany Farid of UC Berkeley discusses how artificial intelligence can create fake media, how it proliferates and what people can do to guard against it.
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CREDIT: HUNNIMEDIA FOR KNOWABLE MAGAZINE
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The technology gets its nickname from Deepfakes, an anonymous Reddit user who launched the movement in November 2017 by posting AI-generated videos in which the faces of celebrities such as Scarlett Johansson and Gal Gadot are mapped onto the bodies of porn stars in action. This kind of non-consensual celebrity pornography still accounts for about 95 percent of all the deepfakes out there, with most of the rest being jokes of the Nicolas Cage variety.
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But while the current targets are at least somewhat protected by fame — “People assume it’s not actually me in a porno, however demeaning it is,” Johansson said in a 2018 interview — abuse-survivor advocate Adam Dodge figures that non-celebrities will increasingly be targeted, as well. Old-fashioned revenge porn is a ubiquitous feature of domestic violence cases as it is, says Dodge, who works with victims of such abuse as the legal director for Laura’s House, a nonprofit agency in Orange County, California. And now with deepfakes, he says, “unsophisticated perpetrators no longer require nudes or a sex tape to threaten a victim. They can simply manufacture them.”
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Then there’s the potential for political abuse. Want to discredit an enemy? Indian journalist Rana Ayyub knows how that works: In April 2018, her face was in a deepfake porn video that went viral across the subcontinent, apparently because she is an outspoken Muslim woman whose investigations offended India’s ruling party. Or how about subverting democracy? We got a taste of that in the fake-news and disinformation campaigns of 2016, says Farid. And there could be more to come. Imagine it’s election eve in 2020 or 2024, and someone posts a convincing deepfake video of a presidential candidate doing or saying something vile. In the hours or days it would take to expose the fakery, Farid says, millions of voters might go to the polls thinking the video is real — thereby undermining the outcome and legitimacy of the election.
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Meanwhile, don’t forget old-fashioned greed. With today’s deepfake technology, Farid says, “I could create a fake video of Jeff Bezos saying, ‘I’m quitting Amazon,’ or ‘Amazon’s profits are down 10 percent.’ ” And if that video went viral for even a few minutes, he says, markets could be thrown into turmoil. “You could have global stock manipulation to the tune of billions of dollars.”
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And beyond all that, Farid says, looms the “terrifying landscape” of the post-truth world, when deepfakes have become ubiquitous, seeing is no longer believing and miscreants can bask in a whole new kind of plausible deniability. Body-cam footage? CCTV tapes? Photographic evidence of human-rights atrocities? Audio of a presidential candidate boasting he can grab women anywhere he wants? “DEEPFAKE!”
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Deepfake video methods can digitally alter a person’s lip movements to match words that they never said. As part of an effort to grow awareness about such technologies through art, the MIT Center for Advanced Virtuality created a fake video showing President Richard Nixon giving a speech about astronauts being stranded on the moon.
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CREDIT: HALSEY BURGUND / MIT CENTER FOR ADVANCED VIRTUALITY
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Thus the widespread concern about deepfake technology, which has triggered an urgent search for answers among journalists, police investigators, insurance companies, human-rights activists, intelligence analysts and just about anyone else who relies on audiovisual evidence.
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Among the leaders in that search has been Sam Gregory, a documentary filmmaker who has spent two decades working for WITNESS, a human-rights organization based in Brooklyn, New York. One of WITNESS’ major goals, says Gregory, is to help people in troubled parts of the world take advantage of dramatically improved cell-phone cameras “to document their realities in ways that are trustworthy and compelling and safe to share.”
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Unfortunately, he adds, “you can’t do that in this day and age without thinking about the downsides” of those technologies — deepfakes being a prime example. So in June 2018, WITNESS partnered with First Draft, a global nonprofit that supports journalists grappling with media manipulation, to host one of the first serious workshops on the subject. Technologists, human-rights activists, journalists and people from social-media platforms developed a roadmap to prepare for a world of deepfakes.
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More WITNESS-sponsored meetings have followed, refining that roadmap down to a few key issues. One is a technical challenge for researchers: Find a quick and easy way to tell trustworthy media from fake. Another is a legal and economic challenge for big social media platforms such as Facebook and YouTube: Where does your responsibility lie? After all, says Farid, “if we did not have a delivery mechanism for deepfakes in the form of social media, this would not be a threat that we are concerned about.”
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And for everyone there is the challenge of education — helping people understand what deepfake technology is, and what it can do.
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First, deep learning
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Deepfakes have their roots in the triumph of the “neural networks,” a once-underdog form of artificial intelligence that has re-emerged to power today’s revolution in driverless cars, speech and image recognition, and a host of other applications.
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Although the neural-network idea can be traced back to the 1940s, it began to take hold only in the 1960s, when AI was barely a decade old and progress was frustratingly slow. Trivial-seeming aspects of intelligence, such as recognizing a face or understanding a spoken word, were proving to be far tougher to program than supposedly hard skills like playing chess or solving cryptograms. In response, a cadre of rebel researchers declared that AI should give up trying to generate intelligent behavior with high-level algorithms — then the mainstream approach — and instead do so from the bottom up by simulating the brain.
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To recognize what’s in an image, for example, a neural network would pipe the raw pixels into a network of simulated nodes, which were highly simplified analogs of brain cells known as neurons. These signals would then flow from node to node along connections: analogs of the synaptic junctions that pass nerve impulses from one neuron to the next. Depending on how the connections were organized, the signals would combine and split as they went, until eventually they would activate one of a series of output nodes. Each output, in turn, would correspond to a high-level classification of the image’s content — “puppy,” for example, or “eagle,” or “George.”
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The payoff, advocates argued, was that neural networks could be much better than standard, algorithmic AI at dealing with real-world inputs, which tend to be full of noise, distortion and ambiguity. (Say “service station” out loud. They’re two words — but it’s hard to hear the boundary.)
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And better still, the networks wouldn’t need to be programmed, just trained. Simply show your network a few zillion examples of, say, puppies and not-puppies, like so many flash cards, and ask it to guess what each image shows. Then feed any wrong answers back through all those connections, tweaking each one to amplify or dampen the signals in a way that produces a better outcome next time.
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The earliest attempts to implement neural networks weren’t terribly impressive, which explains the underdog status. But in the 1980s, researchers greatly improved the performance of networks by organizing the nodes into a series of layers, which were roughly analogous to different processing centers in the brain’s cortex. So in the image example, pixel data would flow into an input layer; then be combined and fed into a second layer that contained nodes responding to simple features like lines and curves; then into a third layer that had nodes responding to more complex shapes such as noses; and so on.
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Later, in the mid-2000s, exponential advances in computer power allowed advocates to develop networks that were far “deeper” than before — meaning they could be built not just with one or two layers, but dozens. The performance gains were spectacular. In 2009, neural network pioneer Geoffrey Hinton and two of his graduate students at the University of Toronto demonstrated that such a “deep-learning” network could recognize speech much better than any other known method. Then in 2012, Hinton and two other students showed that a deep-learning network could recognize images better than any standard vision system — and neural networks were underdogs no more. Tech giants such as Google, Microsoft and Amazon quickly started incorporating deep-learning techniques into every product they could, as did researchers in biomedicine, high-energy physics and many other fields.
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$\"Graphic$
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The neural-network approach to artificial intelligence is designed to model the brain’s neurons and links with a web of simulated nodes and connections. Such a network processes signals by combining and recombining them as they flow from node to node. Early networks were small and limited. But today’s versions are far more powerful, thanks to modern computers that can run networks both bigger and “deeper” than before, with their nodes organized into many more layers.
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Yet as spectacular as deep learning’s successes were, they almost always boiled down to some form of recognition or classification — for example, Does this image from the drone footage show a rocket launcher? It wasn’t until 2014 that a PhD student at the University of Montreal, Ian Goodfellow, showed how deep learning could be used to generate images in a practical way.
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Goodfellow’s idea, dubbed the generative adversarial network (GAN), was to gradually improve an image’s quality through competition — an ever-escalating race in which two neural networks try to outwit each other. The process begins when a “generator” network tries to create a synthetic image that looks like it belongs to a particular set of images — say, a big collection of faces. That initial attempt might be crude. The generator then passes its effort to a “discriminator” network that tries to see through the deception: Is the generator’s output fake, yes or no? The generator takes that feedback, tries to learn from its mistakes and adjusts its connections to do better on the next cycle. But so does the discriminator — on and on they go, cycle after cycle, until the generator’s output has improved to the point where the discriminator is baffled.
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The images generated for that first GAN paper were low-resolution and not always convincing. But as Facebook’s AI chief Yann LeCun later put it, GANs were “the coolest idea in deep learning in the last 20 years.” Researchers were soon jumping in with a multitude of variations on the idea. And along the way, says Farid, the quality of the generated imagery increased at an astonishing rate. “I don’t think I’ve ever seen a technology develop as fast,” he says.
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$\"Diagram$
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A generative adversarial network (GAN) learns to generate images by pitting two neural networks against each other. The generator network tries to create an image that looks real, while a discriminator network tries to see through the deception — and both try to learn from their mistakes. After enough cycles, the results can look startlingly realistic.
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Make it till you fake it
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What few researchers seemed to have anticipated, however, was that the malicious uses of their technology would develop just as rapidly. Deepfakes, the Redditor, kicked things off on November 2, 2017, with the launch of the subReddit /r/deepfakes as a showcase for GAN-generated porn. Specifically, he announced that he was using open-source AI software from Google and elsewhere to implement previously scattered academic research on face-swapping: putting one person’s face onto another person’s body.
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Face swapping was nothing new. But in conventional applications such as Photoshop, it had always been a digital cut-and-paste operation that looked pretty obvious unless the replacement face had the same lighting and orientation as the original. The GAN approach made such swapping seamless. First, the generator network would be trained on thousands of images and videos of, say, the film star Gadot, producing a 3D model of her head and face. Next, the generator could use this model to map Gadot’s face digitally onto the target, giving it the same alignment, expressions and lighting as an actor in, say, an adult film. And then it would repeat the process frame by frame to make a video.
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Deepfakes’ initial results weren’t quite good enough to fool a careful observer — but still gained a following. He soon had a host of imitators, especially after another anonymous individual packaged Deepfake’s algorithm into self-contained “FakeApp” software, and launched it as a free download in January 2018. Within a month, sensing a lawsuit waiting to happen, Reddit had banned non-consensual deepfake porn videos outright — as did the world’s largest porn sharing site, Pornhub. (“How bad do you have to be to be banned by Reddit and Pornhub at the same time?” says Farid.)
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Yet other sites were already coming online, and the flood continued — as did anxieties about the software’s potential use in the fake-news era. Heightening those anxieties were two variations that predated Deepfakes’ face-swap software, and that many experts consider more threatening. “Puppet master,” a facial-reenactment approach pioneered by researchers at Stanford University and others in 2016 with the goal of improving facial motion-capture techniques for video games and movies, allowed an actor to impose her facial expressions on someone in, say, a YouTube video — in real time. “Lip sync,” pioneered at the University of Washington in 2017 with similar goals, could start with an existing video and change the targeted person’s mouth movements to correspond to a fake audio track.
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A video describes one of the technologies that could be used to make convincing deepfakes. This approach offers a way to capture an actor’s facial expressions and embed them on an existing video of another person.
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CREDIT: ASSOCIATION FOR COMPUTING MACHINERY (ACM)
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Legitimate goals or not, these two techniques together could make anyone say or do anything. In April 2018, film director Jordan Peele dramatized the issue with a lip-synced fake video of former President Obama giving a public-service announcement about the dangers of deepfakes on Buzzfeed. And later that same year, when WITNESS’ Gregory and his colleagues started working on the roadmap for dealing with the problem, the issue took the form of a technical challenge for researchers: Find a simple way to tell trustworthy media from fake.
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Detecting forgeries
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The good news is that this already was a research priority well before deepfakes came along, in response to the surge in low-tech “cheapfakes” made with non-AI-based tools such as Photoshop. Many of the counter-techniques have turned out to apply to all forms of manipulation.
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$\"Images$
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One approach uses generative adversarial network techniques to turn real images into altered ones. The program called CycleGAN transforms horses into zebras, winter into summer and vice versa.
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CREDIT: J. ZHU ET AL / ICCV 2017
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Broadly speaking, the efforts to date follow two strategies: authentication and detection.
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With authentication — the focus of startups such as Truepic in La Jolla, Calif., and Amber Video in San Francisco — the idea is to give each media file a software badge guaranteeing it has not been manipulated.
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In Truepic’s case, says company vice president Mounir Ibrahim, the software looks like any other smartphone photo app. But in its inner workings, he says, the app inscribes each image or video it records with the digital equivalent of a DNA fingerprint. Anyone could then verify that file’s authenticity by scanning it with a known algorithm. If the scan and fingerprint do not match, it means the file has been manipulated.
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To safeguard against fakery of the digital fingerprints, the software creates a public record of each fingerprint using the blockchain technique originally developed for cryptocurrencies like Bitcoin. “And what that does is close the digital chain of custody,” says Ibrahim. Records in the blockchain are effectively un-hackable: They are distributed across computers all over the world, yet are so intertwined that you couldn’t change one without making impossibly intricate changes to all the others simultaneously.
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Amber Video’s approach is broadly similar, says company CEO Shamir Allibhai. Like Ibrahim, he emphasizes that his company is not associated with Bitcoin itself, nor dependent on cryptocurrencies in any way. The important thing about a blockchain is that it’s public, distributed and immutable, says Allibhai. So you could share, say, a 15-minute segment of a surveillance video with police, prosecutors, defense attorneys, judges, jurors, reporters and the general public — across years of appeals — and all of them could confirm the clip’s veracity. Says Allibhai: “You only need to trust mathematics.”
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Skeptics say that a blockchain-based authentication scheme isn’t likely to become universal for a long time, if ever; it would essentially require every digital camera on the planet to incorporate the same standard algorithm. And while it could become viable for organizations that can insist on authenticated media — think courts, police departments and insurance companies — it doesn’t do anything about the myriad digital images and videos already out there.
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Thus the second strategy: detecting manipulations after the fact. That’s the approach of Amsterdam-based startup DeepTrace, says Henry Ajder, head of threat intelligence at the company. The trick, he says, is not to get hung up on specific image artifacts, which can change rapidly as technology evolves. He points to a classic case in 2018, when researchers at the State University of New York in Albany found that figures in deepfake videos don’t blink realistically (mainly because the images used to train the GANs rarely show people with their eyes shut). Media accounts hailed this as a foolproof way of detecting deepfakes, says Ajder. But just as the researchers themselves had predicted, he says, “within a couple of months new fakes were being developed that were perfectly good at blinking.”
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A better detection approach is to focus on harder-to-fake tells, such as the ones that arise from the way a digital camera turns light into bits. This process starts when the camera’s lens focuses incoming photons onto the digital equivalent of film: a sensor chip that collects the light energy in a rectangular grid of pixels. As that happens, says Edward Delp, an electrical engineer at Purdue University in Indiana, each sensor leaves a signature on the image — a subtle pattern of spontaneous electrical static unique to that chip. “You can exploit those unique signatures to determine which camera took which picture,” says Delp. And if someone tries to splice in an object photographed with a different camera — or a face synthesized with AI — “we can detect that there is an anomaly.”
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Similarly, when algorithms like JPEG and MPV4 compress image and video files to a size that can be stored on a digital camera’s memory chip, they produce characteristic correlations between neighboring pixels. So again, says Jeff Smith, who works on media forensics at the University of Colorado, Denver, “if you change the pixels due to face swapping, whether traditional or deepfake, you’ve disrupted the relationships between the pixels.” From there, an investigator can build up a scan of the image or video to show exactly what parts have been manipulated.
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Unfortunately, Smith adds, neither the noise nor the compression technique is bulletproof. Once the manipulation is done, “the next step is uploading the video to the internet and hoping it goes viral.” And as soon as that happens, YouTube or another hosting platform puts the file through its own compression algorithm — as does every site the video is shared with after that. Add up all those compressions, says Smith, “and that can wash out the correlations that we were looking for.”
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That’s why detection methods also have to look beyond the pixels. Say you have a video that was recorded in daylight and want to check whether a car shown was really in the original. The perspective could be off, Smith says, “or there could be shadows within the car image that don’t match the shadows in the original image.” Any such violation of basic physics could be a red flag for the detection system, he says.
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In addition, says Delp, you could check an image’s context against other sources of knowledge. For example, does a rainy-day video’s digital timestamp match up with weather-service records for that alleged place and time? Or, for a video shot indoors: “We can extract the 60-hertz line frequency from the lights in the room,” Delp says, “and then determine geographically whether the place you say the video is shot is where the video was actually shot.” That’s possible, he explains, because the ever-changing balance of supply and demand means that the power-line frequency is never precisely 60 cycles per second, and the power companies keep very careful records of how that frequency varies at each location.
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Or maybe you have a video of someone talking. One way to tell if the speaker has been deepfaked is to look at their unconscious habits — quirks that Farid and his colleagues have found to be as individual as fingerprints. For example, says Farid, “when President Obama frowns, he tends to tilt his head downward, and when he smiles he tends to turn his head upwards into the left.” Obama also tends to have very animated eyebrows. “Senator [Elizabeth] Warren, on the other hand, tends to not smile a lot, but moves her head left and right quite a bit.” And President Donald Trump tends to be un-animated except for his chin and mouth, says Farid. “They are extremely animated in a very particular way.”
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Farid and his colleagues have analyzed hours upon hours of videos to map those quirks for various world leaders. So if anyone tries to create a deepfake of one of those leaders, he says, “whether it’s a face swap, a lip sync or a puppet master, those properties are disrupted and we can detect it with a fair degree of accuracy.”
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Not by technology alone
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To spur the development of such technologies, tech companies such as Amazon, Facebook and Microsoft have joined with WITNESS, First Draft and others to launch a Deepfake Detection Challenge: Participants submit code that will be scored on how well it can detect a set of reference fakes. Cash prizes range up to $500,000.
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In the meantime, though, there is a widespread consensus in the field that technology will never solve the deepfake challenge by itself. Most of the issues that have surfaced in the WITNESS roadmap exercises are non-technological. What’s the best way of raising public awareness, for example? How do you regulate the technology without killing legitimate applications? And how much responsibility should be borne by social media?
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In April 2018, director Jordan Peele worked with Buzzfeed Media to demonstrate the power of deepfakes. They created a video of former President Barack Obama (voiced by Peele) giving a public-service announcement about the dangers of deepfakes — an announcement that Obama never made.
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CREDIT: BUZZFEEDVIDEO
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Facebook partially answered that last question on January 6, when it announced it would ban any deepfake that was intended to deceive the viewers. It remains to be seen how effective that ban will be. And in any case, there are other platforms still to be heard from, and many issues still unresolved.
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On the technological front, should the platforms start demanding a valid authentication tag for each file that’s posted? Or failing that, do they have a responsibility to check each file for signs of manipulation? It won’t be long before the detection algorithms are fast enough to keep up, says Delp. And the platforms already do extensive vetting to check for copyright violations, as well as for illegal content such as child pornography, so deepfake checks would fit right in. Alternatively, the platforms could go the crowdsourcing route by making the detection tools available for users to flag deepfakes on their own — complete with leaderboards and bounties for each one detected.
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There’s a gnarlier question, though — and one that gets caught up in the larger debate over fake news and disinformation in general: What should sites do when they discover bogus posts? Some might be tempted to go the libertarian route that Facebook has taken with deceptive political ads, or non-AI video manipulation: Simply label the known fakes and let the viewers beware.
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Unfortunately, that overlooks the damage such a post can do — given that a lot of people will believe it’s real despite the “fake” label. Should, then, sites take down deepfakes as soon as they are discovered? That’s pretty clear-cut when it comes to non-consensual porn, says Farid: Not only do most mainstream sites ban pornography of any kind, but even those that don’t can see there’s a specific person being hurt. But there is a reason that Facebook’s ban carves out a large exception for Nicolas Cage-style joke videos, and deepfakes that are clearly intended as satire, parody or political commentary. In those cases, says Farid, “the legislative and regulatory side is complex because of the free-speech issue.”
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A lot of people are afraid to touch this question, says Kavanagh, the RAND political scientist. Particularly in the Silicon Valley culture, she says, “there’s often a sense that either we have no regulation, or we have a Ministry of Truth.” People aren’t thinking about the vast gray area in between, which is where past generations hammered out workable ways to manage print newspapers, radio and television. “I don't necessarily have a good answer to what we should do about the new media environment,” Kavanagh says. “But I do think that the gray areas are where we need to have this conversation.”
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By M. Mitchell Waldrop 03.16.2020
\n\n","field_author_bios":"
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M. Mitchell Waldrop is a freelance writer based in Washington, DC.
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SOURCE: THISPERSONDOESNOTEXIST.COM
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Synthetic media: The real trouble with deepfakes
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Keeping on top of manipulated videos and images is no easy feat. Scientists trace the roots of their proliferation, dig up new techniques to counter digital forgeries and warn of the growing dangers ahead.
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By M. Mitchell Waldrop
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3.16.2020
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The snapshots above look like people you’d know. Your daughter’s best friend from college, maybe? That guy from human resources at work? The emergency-room doctor who took care of your sprained ankle? One of the kids from down the street?
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Nope. All of these images are “deepfakes” — the nickname for computer-generated, photorealistic media created via cutting-edge artificial intelligence technology. They are just one example of what this fast-evolving method can do. (You could create synthetic images yourself at ThisPersonDoesNotExist.com.) Hobbyists, for example, have used the same AI techniques to populate YouTube with a host of startlingly lifelike video spoofs — the kind that show real people such as Barack Obama or Vladimir Putin doing or saying goofy things they never did or said, or that revise famous movie scenes to give actors like Amy Adams or Sharon Stone the face of Nicolas Cage. All the hobbyists need is a PC with a high-end graphics chip, and maybe 48 hours of processing time.
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It’s good fun, not to mention jaw-droppingly impressive. And coming down the line are some equally remarkable applications that could make quick work out of once-painstaking tasks: filling in gaps and scratches in damaged images or video; turning satellite photos into maps; creating realistic streetscape videos to train autonomous vehicles; giving a natural-sounding voice to those who have lost their own; turning Hollywood actors into their older or younger selves; and much more.
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Yet this technology has an obvious — and potentially enormous — dark side. Witness the many denunciations of deepfakes as a menace, Facebook’s decision in January to ban (some) deepfakes outright and Twitter’s announcement a month later that it would follow suit.
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“Deepfakes play to our weaknesses,” explains Jennifer Kavanagh, a political scientist at the RAND Corporation and coauthor of “Truth Decay,” a 2018 RAND report about the diminishing role of facts and data in public discourse. When we see a doctored video that looks utterly real, she says, “it’s really hard for our brains to disentangle whether that’s true or false.” And the internet being what it is, there are any number of online scammers, partisan zealots, state-sponsored hackers and other bad actors eager to take advantage of that fact.
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“The threat here is not, ‘Oh, we have fake content!’” says Hany Farid, a computer scientist at the University of California, Berkeley, and author of an overview of image forensics in the 2019 Annual Review of Vision Science. Media manipulation has been around forever. “The threat is the democratization of Hollywood-style technology that can create really compelling fake content.” It’s photorealism that requires no skill or effort, he says, coupled with a social-media ecosystem that can spread that content around the world with a mouse click.
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The technology gets its nickname from Deepfakes, an anonymous Reddit user who launched the movement in November 2017 by posting AI-generated videos in which the faces of celebrities such as Scarlett Johansson and Gal Gadot are mapped onto the bodies of porn stars in action. This kind of non-consensual celebrity pornography still accounts for about 95 percent of all the deepfakes out there, with most of the rest being jokes of the Nicolas Cage variety.
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But while the current targets are at least somewhat protected by fame — “People assume it’s not actually me in a porno, however demeaning it is,” Johansson said in a 2018 interview — abuse-survivor advocate Adam Dodge figures that non-celebrities will increasingly be targeted, as well. Old-fashioned revenge porn is a ubiquitous feature of domestic violence cases as it is, says Dodge, who works with victims of such abuse as the legal director for Laura’s House, a nonprofit agency in Orange County, California. And now with deepfakes, he says, “unsophisticated perpetrators no longer require nudes or a sex tape to threaten a victim. They can simply manufacture them.”
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Then there’s the potential for political abuse. Want to discredit an enemy? Indian journalist Rana Ayyub knows how that works: In April 2018, her face was in a deepfake porn video that went viral across the subcontinent, apparently because she is an outspoken Muslim woman whose investigations offended India’s ruling party. Or how about subverting democracy? We got a taste of that in the fake-news and disinformation campaigns of 2016, says Farid. And there could be more to come. Imagine it’s election eve in 2020 or 2024, and someone posts a convincing deepfake video of a presidential candidate doing or saying something vile. In the hours or days it would take to expose the fakery, Farid says, millions of voters might go to the polls thinking the video is real — thereby undermining the outcome and legitimacy of the election.
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Meanwhile, don’t forget old-fashioned greed. With today’s deepfake technology, Farid says, “I could create a fake video of Jeff Bezos saying, ‘I’m quitting Amazon,’ or ‘Amazon’s profits are down 10 percent.’ ” And if that video went viral for even a few minutes, he says, markets could be thrown into turmoil. “You could have global stock manipulation to the tune of billions of dollars.”
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And beyond all that, Farid says, looms the “terrifying landscape” of the post-truth world, when deepfakes have become ubiquitous, seeing is no longer believing and miscreants can bask in a whole new kind of plausible deniability. Body-cam footage? CCTV tapes? Photographic evidence of human-rights atrocities? Audio of a presidential candidate boasting he can grab women anywhere he wants? “DEEPFAKE!”
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Thus the widespread concern about deepfake technology, which has triggered an urgent search for answers among journalists, police investigators, insurance companies, human-rights activists, intelligence analysts and just about anyone else who relies on audiovisual evidence.
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Among the leaders in that search has been Sam Gregory, a documentary filmmaker who has spent two decades working for WITNESS, a human-rights organization based in Brooklyn, New York. One of WITNESS’ major goals, says Gregory, is to help people in troubled parts of the world take advantage of dramatically improved cell-phone cameras “to document their realities in ways that are trustworthy and compelling and safe to share.”
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Unfortunately, he adds, “you can’t do that in this day and age without thinking about the downsides” of those technologies — deepfakes being a prime example. So in June 2018, WITNESS partnered with First Draft, a global nonprofit that supports journalists grappling with media manipulation, to host one of the first serious workshops on the subject. Technologists, human-rights activists, journalists and people from social-media platforms developed a roadmap to prepare for a world of deepfakes.
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More WITNESS-sponsored meetings have followed, refining that roadmap down to a few key issues. One is a technical challenge for researchers: Find a quick and easy way to tell trustworthy media from fake. Another is a legal and economic challenge for big social media platforms such as Facebook and YouTube: Where does your responsibility lie? After all, says Farid, “if we did not have a delivery mechanism for deepfakes in the form of social media, this would not be a threat that we are concerned about.”
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And for everyone there is the challenge of education — helping people understand what deepfake technology is, and what it can do.
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First, deep learning
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Deepfakes have their roots in the triumph of the “neural networks,” a once-underdog form of artificial intelligence that has re-emerged to power today’s revolution in driverless cars, speech and image recognition, and a host of other applications.
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Although the neural-network idea can be traced back to the 1940s, it began to take hold only in the 1960s, when AI was barely a decade old and progress was frustratingly slow. Trivial-seeming aspects of intelligence, such as recognizing a face or understanding a spoken word, were proving to be far tougher to program than supposedly hard skills like playing chess or solving cryptograms. In response, a cadre of rebel researchers declared that AI should give up trying to generate intelligent behavior with high-level algorithms — then the mainstream approach — and instead do so from the bottom up by simulating the brain.
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To recognize what’s in an image, for example, a neural network would pipe the raw pixels into a network of simulated nodes, which were highly simplified analogs of brain cells known as neurons. These signals would then flow from node to node along connections: analogs of the synaptic junctions that pass nerve impulses from one neuron to the next. Depending on how the connections were organized, the signals would combine and split as they went, until eventually they would activate one of a series of output nodes. Each output, in turn, would correspond to a high-level classification of the image’s content — “puppy,” for example, or “eagle,” or “George.”
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The payoff, advocates argued, was that neural networks could be much better than standard, algorithmic AI at dealing with real-world inputs, which tend to be full of noise, distortion and ambiguity. (Say “service station” out loud. They’re two words — but it’s hard to hear the boundary.)
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And better still, the networks wouldn’t need to be programmed, just trained. Simply show your network a few zillion examples of, say, puppies and not-puppies, like so many flash cards, and ask it to guess what each image shows. Then feed any wrong answers back through all those connections, tweaking each one to amplify or dampen the signals in a way that produces a better outcome next time.
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The earliest attempts to implement neural networks weren’t terribly impressive, which explains the underdog status. But in the 1980s, researchers greatly improved the performance of networks by organizing the nodes into a series of layers, which were roughly analogous to different processing centers in the brain’s cortex. So in the image example, pixel data would flow into an input layer; then be combined and fed into a second layer that contained nodes responding to simple features like lines and curves; then into a third layer that had nodes responding to more complex shapes such as noses; and so on.
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Later, in the mid-2000s, exponential advances in computer power allowed advocates to develop networks that were far “deeper” than before — meaning they could be built not just with one or two layers, but dozens. The performance gains were spectacular. In 2009, neural network pioneer Geoffrey Hinton and two of his graduate students at the University of Toronto demonstrated that such a “deep-learning” network could recognize speech much better than any other known method. Then in 2012, Hinton and two other students showed that a deep-learning network could recognize images better than any standard vision system — and neural networks were underdogs no more. Tech giants such as Google, Microsoft and Amazon quickly started incorporating deep-learning techniques into every product they could, as did researchers in biomedicine, high-energy physics and many other fields.
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Yet as spectacular as deep learning’s successes were, they almost always boiled down to some form of recognition or classification — for example, Does this image from the drone footage show a rocket launcher? It wasn’t until 2014 that a PhD student at the University of Montreal, Ian Goodfellow, showed how deep learning could be used to generate images in a practical way.
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Goodfellow’s idea, dubbed the generative adversarial network (GAN), was to gradually improve an image’s quality through competition — an ever-escalating race in which two neural networks try to outwit each other. The process begins when a “generator” network tries to create a synthetic image that looks like it belongs to a particular set of images — say, a big collection of faces. That initial attempt might be crude. The generator then passes its effort to a “discriminator” network that tries to see through the deception: Is the generator’s output fake, yes or no? The generator takes that feedback, tries to learn from its mistakes and adjusts its connections to do better on the next cycle. But so does the discriminator — on and on they go, cycle after cycle, until the generator’s output has improved to the point where the discriminator is baffled.
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The images generated for that first GAN paper were low-resolution and not always convincing. But as Facebook’s AI chief Yann LeCun later put it, GANs were “the coolest idea in deep learning in the last 20 years.” Researchers were soon jumping in with a multitude of variations on the idea. And along the way, says Farid, the quality of the generated imagery increased at an astonishing rate. “I don’t think I’ve ever seen a technology develop as fast,” he says.
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Make it till you fake it
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What few researchers seemed to have anticipated, however, was that the malicious uses of their technology would develop just as rapidly. Deepfakes, the Redditor, kicked things off on November 2, 2017, with the launch of the subReddit /r/deepfakes as a showcase for GAN-generated porn. Specifically, he announced that he was using open-source AI software from Google and elsewhere to implement previously scattered academic research on face-swapping: putting one person’s face onto another person’s body.
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Face swapping was nothing new. But in conventional applications such as Photoshop, it had always been a digital cut-and-paste operation that looked pretty obvious unless the replacement face had the same lighting and orientation as the original. The GAN approach made such swapping seamless. First, the generator network would be trained on thousands of images and videos of, say, the film star Gadot, producing a 3D model of her head and face. Next, the generator could use this model to map Gadot’s face digitally onto the target, giving it the same alignment, expressions and lighting as an actor in, say, an adult film. And then it would repeat the process frame by frame to make a video.
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Deepfakes’ initial results weren’t quite good enough to fool a careful observer — but still gained a following. He soon had a host of imitators, especially after another anonymous individual packaged Deepfake’s algorithm into self-contained “FakeApp” software, and launched it as a free download in January 2018. Within a month, sensing a lawsuit waiting to happen, Reddit had banned non-consensual deepfake porn videos outright — as did the world’s largest porn sharing site, Pornhub. (“How bad do you have to be to be banned by Reddit and Pornhub at the same time?” says Farid.)
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Yet other sites were already coming online, and the flood continued — as did anxieties about the software’s potential use in the fake-news era. Heightening those anxieties were two variations that predated Deepfakes’ face-swap software, and that many experts consider more threatening. “Puppet master,” a facial-reenactment approach pioneered by researchers at Stanford University and others in 2016 with the goal of improving facial motion-capture techniques for video games and movies, allowed an actor to impose her facial expressions on someone in, say, a YouTube video — in real time. “ Lip sync,” pioneered at the University of Washington in 2017 with similar goals, could start with an existing video and change the targeted person’s mouth movements to correspond to a fake audio track.
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Legitimate goals or not, these two techniques together could make anyone say or do anything. In April 2018, film director Jordan Peele dramatized the issue with a lip-synced fake video of former President Obama giving a public-service announcement about the dangers of deepfakes on Buzzfeed. And later that same year, when WITNESS’ Gregory and his colleagues started working on the roadmap for dealing with the problem, the issue took the form of a technical challenge for researchers: Find a simple way to tell trustworthy media from fake.
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Detecting forgeries
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The good news is that this already was a research priority well before deepfakes came along, in response to the surge in low-tech “cheapfakes” made with non-AI-based tools such as Photoshop. Many of the counter-techniques have turned out to apply to all forms of manipulation.
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Broadly speaking, the efforts to date follow two strategies: authentication and detection.
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With authentication — the focus of startups such as Truepic in La Jolla, Calif., and Amber Video in San Francisco — the idea is to give each media file a software badge guaranteeing it has not been manipulated.
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In Truepic’s case, says company vice president Mounir Ibrahim, the software looks like any other smartphone photo app. But in its inner workings, he says, the app inscribes each image or video it records with the digital equivalent of a DNA fingerprint. Anyone could then verify that file’s authenticity by scanning it with a known algorithm. If the scan and fingerprint do not match, it means the file has been manipulated.
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To safeguard against fakery of the digital fingerprints, the software creates a public record of each fingerprint using the blockchain technique originally developed for cryptocurrencies like Bitcoin. “And what that does is close the digital chain of custody,” says Ibrahim. Records in the blockchain are effectively un-hackable: They are distributed across computers all over the world, yet are so intertwined that you couldn’t change one without making impossibly intricate changes to all the others simultaneously.
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Amber Video’s approach is broadly similar, says company CEO Shamir Allibhai. Like Ibrahim, he emphasizes that his company is not associated with Bitcoin itself, nor dependent on cryptocurrencies in any way. The important thing about a blockchain is that it’s public, distributed and immutable, says Allibhai. So you could share, say, a 15-minute segment of a surveillance video with police, prosecutors, defense attorneys, judges, jurors, reporters and the general public — across years of appeals — and all of them could confirm the clip’s veracity. Says Allibhai: “You only need to trust mathematics.”
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Skeptics say that a blockchain-based authentication scheme isn’t likely to become universal for a long time, if ever; it would essentially require every digital camera on the planet to incorporate the same standard algorithm. And while it could become viable for organizations that can insist on authenticated media — think courts, police departments and insurance companies — it doesn’t do anything about the myriad digital images and videos already out there.
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Thus the second strategy: detecting manipulations after the fact. That’s the approach of Amsterdam-based startup DeepTrace, says Henry Ajder, head of threat intelligence at the company. The trick, he says, is not to get hung up on specific image artifacts, which can change rapidly as technology evolves. He points to a classic case in 2018, when researchers at the State University of New York in Albany found that figures in deepfake videos don’t blink realistically (mainly because the images used to train the GANs rarely show people with their eyes shut). Media accounts hailed this as a foolproof way of detecting deepfakes, says Ajder. But just as the researchers themselves had predicted, he says, “within a couple of months new fakes were being developed that were perfectly good at blinking.”
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A better detection approach is to focus on harder-to-fake tells, such as the ones that arise from the way a digital camera turns light into bits. This process starts when the camera’s lens focuses incoming photons onto the digital equivalent of film: a sensor chip that collects the light energy in a rectangular grid of pixels. As that happens, says Edward Delp, an electrical engineer at Purdue University in Indiana, each sensor leaves a signature on the image — a subtle pattern of spontaneous electrical static unique to that chip. “You can exploit those unique signatures to determine which camera took which picture,” says Delp. And if someone tries to splice in an object photographed with a different camera — or a face synthesized with AI — “we can detect that there is an anomaly.”
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Similarly, when algorithms like JPEG and MPV4 compress image and video files to a size that can be stored on a digital camera’s memory chip, they produce characteristic correlations between neighboring pixels. So again, says Jeff Smith, who works on media forensics at the University of Colorado, Denver, “if you change the pixels due to face swapping, whether traditional or deepfake, you’ve disrupted the relationships between the pixels.” From there, an investigator can build up a scan of the image or video to show exactly what parts have been manipulated.
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Unfortunately, Smith adds, neither the noise nor the compression technique is bulletproof. Once the manipulation is done, “the next step is uploading the video to the internet and hoping it goes viral.” And as soon as that happens, YouTube or another hosting platform puts the file through its own compression algorithm — as does every site the video is shared with after that. Add up all those compressions, says Smith, “and that can wash out the correlations that we were looking for.”
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That’s why detection methods also have to look beyond the pixels. Say you have a video that was recorded in daylight and want to check whether a car shown was really in the original. The perspective could be off, Smith says, “or there could be shadows within the car image that don’t match the shadows in the original image.” Any such violation of basic physics could be a red flag for the detection system, he says.
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In addition, says Delp, you could check an image’s context against other sources of knowledge. For example, does a rainy-day video’s digital timestamp match up with weather-service records for that alleged place and time? Or, for a video shot indoors: “We can extract the 60-hertz line frequency from the lights in the room,” Delp says, “and then determine geographically whether the place you say the video is shot is where the video was actually shot.” That’s possible, he explains, because the ever-changing balance of supply and demand means that the power-line frequency is never precisely 60 cycles per second, and the power companies keep very careful records of how that frequency varies at each location.
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Or maybe you have a video of someone talking. One way to tell if the speaker has been deepfaked is to look at their unconscious habits — quirks that Farid and his colleagues have found to be as individual as fingerprints. For example, says Farid, “when President Obama frowns, he tends to tilt his head downward, and when he smiles he tends to turn his head upwards into the left.” Obama also tends to have very animated eyebrows. “Senator [Elizabeth] Warren, on the other hand, tends to not smile a lot, but moves her head left and right quite a bit.” And President Donald Trump tends to be un-animated except for his chin and mouth, says Farid. “They are extremely animated in a very particular way.”
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Farid and his colleagues have analyzed hours upon hours of videos to map those quirks for various world leaders. So if anyone tries to create a deepfake of one of those leaders, he says, “whether it’s a face swap, a lip sync or a puppet master, those properties are disrupted and we can detect it with a fair degree of accuracy.”
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Not by technology alone
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To spur the development of such technologies, tech companies such as Amazon, Facebook and Microsoft have joined with WITNESS, First Draft and others to launch a Deepfake Detection Challenge: Participants submit code that will be scored on how well it can detect a set of reference fakes. Cash prizes range up to $500,000.
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In the meantime, though, there is a widespread consensus in the field that technology will never solve the deepfake challenge by itself. Most of the issues that have surfaced in the WITNESS roadmap exercises are non-technological. What’s the best way of raising public awareness, for example? How do you regulate the technology without killing legitimate applications? And how much responsibility should be borne by social media?
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Facebook partially answered that last question on January 6, when it announced it would ban any deepfake that was intended to deceive the viewers. It remains to be seen how effective that ban will be. And in any case, there are other platforms still to be heard from, and many issues still unresolved.
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On the technological front, should the platforms start demanding a valid authentication tag for each file that’s posted? Or failing that, do they have a responsibility to check each file for signs of manipulation? It won’t be long before the detection algorithms are fast enough to keep up, says Delp. And the platforms already do extensive vetting to check for copyright violations, as well as for illegal content such as child pornography, so deepfake checks would fit right in. Alternatively, the platforms could go the crowdsourcing route by making the detection tools available for users to flag deepfakes on their own — complete with leaderboards and bounties for each one detected.
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There’s a gnarlier question, though — and one that gets caught up in the larger debate over fake news and disinformation in general: What should sites do when they discover bogus posts? Some might be tempted to go the libertarian route that Facebook has taken with deceptive political ads, or non-AI video manipulation: Simply label the known fakes and let the viewers beware.
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Unfortunately, that overlooks the damage such a post can do — given that a lot of people will believe it’s real despite the “fake” label. Should, then, sites take down deepfakes as soon as they are discovered? That’s pretty clear-cut when it comes to non-consensual porn, says Farid: Not only do most mainstream sites ban pornography of any kind, but even those that don’t can see there’s a specific person being hurt. But there is a reason that Facebook’s ban carves out a large exception for Nicolas Cage-style joke videos, and deepfakes that are clearly intended as satire, parody or political commentary. In those cases, says Farid, “the legislative and regulatory side is complex because of the free-speech issue.”
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A lot of people are afraid to touch this question, says Kavanagh, the RAND political scientist. Particularly in the Silicon Valley culture, she says, “there’s often a sense that either we have no regulation, or we have a Ministry of Truth.” People aren’t thinking about the vast gray area in between, which is where past generations hammered out workable ways to manage print newspapers, radio and television. “I don't necessarily have a good answer to what we should do about the new media environment,” Kavanagh says. “But I do think that the gray areas are where we need to have this conversation.”
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10.1146/knowable-031320-1
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M. Mitchell Waldrop is a freelance writer based in Washington, DC.
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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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$\"Knowable$
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Every owl fancier has a story of the first time they heard an owl — or, rather, didn’t hear one. It’s unforgettable to see an enormous bird, whose wingspan can reach more than six feet, slipping through the air without even a whisper.
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Justin Jaworski’s first close encounter came at a flying exhibition at the Raptor Foundation near Cambridge, England. “They trained the owls to fly very close to the audience,” he says. “My first experience was of ducking to avoid a collision. I heard only a very slight swoosh after it passed.”
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Laboratory measurements have shown that the slight swoosh made by a barn owl is below the threshold of human hearing until the owl is about three feet away — a feat of stealth that biologists and engineers are far from completely understanding. But researchers from both disciplines are working to solve the riddle of silent flight — some with the aim of designing quieter fans, turbine blades and airplane wings.
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$\"Photo$
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A great gray owl (Strix nebulosa) finds a perch on engineer Justin Jaworski.
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CREDIT: JUSTIN JAWORSKI
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Such owl-inspired innovations can reduce noise by as much as 10 decibels, similar to the difference in noise between a passing truck and a passing car, Jaworski and Nigel Peake write in an overview in the 2020 Annual Review of Fluid Mechanics.
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Go gentle
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Jaworski, an engineer at Lehigh University in Pennsylvania, is hardly the first scientist to be captivated by the puzzle of silent owl flight. In 1934, Robert Rule Graham — a British pilot and bird connoisseur — called attention to three structures on owl wings that might account for the owls’ silence.
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More than 80 years later, his “three traits paradigm,” as Christopher Clark calls it, is still cited in many papers on owl wings. “He clearly knew birds very well, and he was an aeronautical engineer,” says Clark, an ornithologist at the University of California, Riverside. “Science was different in the 1930s. In our age of specialization, you don’t get that combination.”
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First, Graham pointed out an unusual structure called the “comb,” which literally looks like a comb projecting forward from the wing’s leading edge. Second, he noted that most of the owl wing is covered with a soft layer of velvety feathers. Finally, he observed that the feathers on the trailing edge of the wing form a ragged fringe.
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Most researchers still agree that the comb, the velvet and the fringe combine in some way to reduce noise, but the owl may have more tricks up its sleeve. “When all is said and done, I think we’ll have a number of mechanisms, including Graham’s,” says Clark.
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To explain how an owl suppresses noise, it would help to identify where the noise comes from in the first place. For an airplane coming in for a landing, a large part of the noise comes not from the engines but from the flow of air around the plane, especially the sound produced at the trailing edge of the wings. The turbulent air rushing past the exposed edges of the wings translates to the dull roar you hear as the plane flies overhead.
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$\"A$
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Researchers trained a Florida barred owl (Strix varia alleni) to fly through a special recording room. The gliding owls generated very little sound in the range of human hearing (people can hear sounds above the dashed line). Low-frequency sounds made by owl flight are inaudible, no matter the distance. Humans can hear flight noise in the mid-range frequencies when the owl is between one and three meters away. Owl wings and feathers are especially good at dampening higher-frequency sounds, which can be heard only if a person is standing within a meter of the noise.
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One way to reduce this noise would be to make the trailing edge of the wing less hard, more porous and more flexible. This may be the function of the owl wing’s ragged fringes. Jaworski and Peake have mathematically calculated how engineers might use such porosity and elasticity to reduce noise, and how to quantify that diminished din.
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Those calculations are supported by wind-tunnel experiments: A variety of porous materials do dial down the noise. Work by Thomas Geyer at Brandenburg University of Technology in Germany has found that a poroelastic wing the size of an owl’s can be about 2 to 5 decibels quieter than a regular wing.
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However, says Geyer, the right porous material is crucial; in the wind-tunnel tests, some materials actually increased high-frequency noise. Measurements of owls in flight show that their wings mute only frequencies higher than 1,600 hertz (on a piano, two-and-a-half octaves above middle C). Since this is roughly where the range of rodent hearing begins, it’s the range that an owl would benefit most from suppressing as it hunts for a meal.
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Jaworski and Ian Clark (no relation to Christopher) of NASA’s Langley Research Center have attempted to mimic the owl’s velvet by covering a standard airfoil with various kinds of fabric. “The winning textile was a wedding veil,” says Jaworski. However, it may not be necessary to donate your nuptial accessories to science, because the researchers got even better results by attaching tiny plastic 3-D–printed “finlets” to the blades of a wind turbine.
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Research suggests that owl wings have three features that contribute to their silent flight: a “comb” structure (just visible at the wing’s top right), ragged trailing edges (visible along the bottom of the wing) and a velvety material that covers much of the upper left of the wing. The comb structure from a different specimen is shown close-up at bottom.
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CREDIT: THOMAS GEYER
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“Over a certain frequency range, we saw a 10-decibel noise reduction,” Jaworski says. “That may not sound like much, but in air acoustics, engineers fight over two or three decibels. Ten decibels is half as noisy. That’s a massive change for any technology.” Siemens, a manufacturer of wind turbines, has apparently been listening, and recently unveiled its second-generation “Dino Tail” turbines that have combs directly inspired by the owl wing.
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Feathery enigma
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Though owl wings are providing new insights into noise reduction for aeronautical engineering, engineers have had less success describing the physics of owl flight. According to ornithologist Clark, the engineers may not even have identified the most important source of noise in owl aviation.
\n\n
If you’re trying to build an owl, rather than a wind turbine or an airplane, you’ll notice several differences. Owls have feathers; airplanes don’t. Owls flap their wings; airplanes don’t. There’s a good reason that aeronautical engineers prefer stationary, solid wings to flapping, feathery ones: They are easier to understand.
\n\n
But if you are a biologist, to ignore flapping is to ignore a fundamental ingredient in avian flight, says Clark. As bird wings flap they change shape, and as they change shape the feathers rub against each other, causing noise. This noise is frictional, not aerodynamic, produced by the contact of solid against solid.
\n\n
In Clark’s view, the purpose of the owl’s velvet and the fringes is to reduce frictional noise between the feathers while flapping. Clark concedes that his argument would be moot if owls glided while hunting, but video evidence shows they do not: They flap when taking off, they flap when landing and they even flap when “coursing” for prey.
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\n
$\"An$
\n\n
\n
Scientists seeking to understand why the owl’s flight differs from other birds have studied the turbulence patterns left in their wake. Here, vortices swirl behind a computer-animated great horned owl, created by Roi Gurka and Elias Balaras using data gathered from wind tunnel experiments. Red and blue indicate vortices spinning in opposite directions. Compared with other birds such as sandpipers and European starlings, the owl’s vortices are small and disorganized, and do not trail very far behind the owl. The mechanism by which the owl suppresses these vortices is not yet understood.
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CREDIT: ROI GURKA
\n
\n\n
And the fringes are not only on the trailing edge of the wing, where the aerodynamic theory would predict them to have the greatest noise-reducing benefit. Fringes also exist on the leading edges of the feathers, where they do not affect aerodynamic noise, as well on some feathers that are not even exposed to the airflow. This suggests that their purpose is not aerodynamic.
\n\n
Clark says that we may be asking the question backward. Instead of asking why owls are so quiet, we should ask why other birds are so loud. The answer is feathers. “Feathers are amazing structures, and probably the reason birds are so successful,” Clark says. But they come with an evolutionary cost: “If you’re going to build a wing out of feathers, they are going to produce frictional sound.” To become silent hunters, owls evolved special adaptations that reduce this disadvantage.
\n\n
Owls are not the only kind of bird that has solved this problem. Some species of Australian frogmouths have independently developed the same adaptations. These birds are also carnivorous and have wings that are soft and fluffy with combs and ragged fringes. In Graham’s day, people assumed that frogmouths were closely related to owls, but genomic analysis has proved that they are not. While less studied than owls, they too are silent flyers.
\n\n
“Evolution often takes a quirky path,” Clark says. “One way you can home in on the underlying mechanical principles, and tell them apart from quirks, is with convergent evolution.” When two unrelated animals have the same adaptation, it suggests that the feature confers a benefit — in this case, stealth.
\n\n
At present, there are two ways to understand owl flight: an engineering view informed by the equations of fluid motion and wind-tunnel experiments, and a biological view based on anatomy, behavior and genomics. A truly integrated story will probably require both. Even engineers realize that idealized studies based on rigid, unfeathered wings are not enough. It’s quite possible that the owl uses its feathers and small shape adjustments of the wing actively, rather than passively, to manipulate airflow. Engineers aren’t even close to understanding this process, which spans several size scales, from the barbs of the feathers to the individual feathers, to the entire wing.
\n\n
“What is missing to us is the microscopic point of view,” says Roi Gurka of Coastal Carolina University in South Carolina, whose experiments with flying owls have led to beautiful computer simulations of the flow field around a flapping owl wing. “I understand the wing,” he says, but understanding the role individual feather morphology plays in noise reduction is another matter.
\n\n
While the scientists debate, the barn owl will continue flying as it always has: its face as round and imperturbable as the moon, its ears trained on its next meal and its feathers treading gently on the air.
\n\n","field_all_authors":"
By Dana Mackenzie 04.07.2020
\n\n","field_author_bios":"
\n
Dana Mackenzie is a mathematician who went rogue and became a writer. His first book, written at age six or seven, was “The Adventures of Owl.”
\n
\n\n","field_banner_alt":"Photo of a barn owl flying under gray skies above snowy ground and dried wintry grasses.","field_banner_title":"Swooping owl","field_caption":"
A barn owl flies low along the shore of Utah’s Great Salt Lake.
\n\n","field_credit":"
CREDIT: ED MacKERROW / IN LIGHT OF NATURE
","field_doi":"10.1146/knowable-040620-1","field_is_hero":"1","metatags":{"referrer":"origin","title":"The silence of the owls: How owls fly without making a sound","description":"No one knows exactly how the nocturnal hunters manage their whisper-soft flight, yet it is inspiring the design of quieter airplanes, fans and wind turbines","google_plus_name":"The silence of the owls","og_title":"The silence of the owls","og_site_name":"Knowable Magazine | Annual Reviews","og_type":"article","twitter_cards_type":"summary_large_image","canonical_url":"/article/technology/2020/how-owls-fly-without-making-a-sound","dcterms_description":"No one knows exactly how the nocturnal hunters manage their whisper-soft flight, yet it is inspiring the design of quieter airplanes, fans and wind turbines","dcterms_identifier":"10.1146/knowable-040620-1","dcterms_publisher":"Annual Reviews","dcterms_title":"The silence of the owls","dcterms_type":"article","fb_admins":"1642929092406128","google_plus_description":"No one knows exactly how the nocturnal hunters manage their whisper-soft flight, yet it is inspiring the design of quieter airplanes, fans and wind turbines","google_plus_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/452/silent-owl-physics-1600x600.jpg?itok=ySmBf7MH","citation_author":"","citation_journal_title":"Knowable Magazine | Annual Reviews","citation_publication_date":"Tuesday, April 7, 2020 - 08:00","citation_title":"The silence of the owls","article_modified_time":"Tuesday, April 7, 2020 - 08:00","article_published_time":"Tuesday, April 7, 2020 - 08:00","og_description":"No one knows exactly how the nocturnal hunters manage their whisper-soft flight, yet it is inspiring the design of quieter airplanes, fans and wind turbines","og_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/452/silent-owl-physics-1600x600.jpg?itok=ySmBf7MH","og_image_height":"600","og_image_type":"image/jpeg","og_image_url":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/452/silent-owl-physics-1600x600.jpg?itok=ySmBf7MH","og_image_width":"1600","og_updated_time":"Tuesday, April 7, 2020 - 08:00","og_url":"/article/technology/2020/how-owls-fly-without-making-a-sound","twitter_cards_description":"No one knows exactly how the nocturnal hunters manage their whisper-soft flight, yet it is inspiring the design of quieter airplanes, fans and wind turbines","twitter_cards_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/452/silent-owl-physics-1600x600.jpg?itok=ySmBf7MH","twitter_cards_image_height":"600","twitter_cards_image_width":"1600","twitter_cards_page_url":"/article/technology/2020/how-owls-fly-without-making-a-sound","twitter_cards_site":"@knowablemag","twitter_cards_title":"The silence of the owls","dc_identifier":"10.1146/knowable-040620-1","pocket-site-verification":"665d7e2e5dc1fa27727a154d5c4e80"},"field_primary_author":"By Dana Mackenzie","field_published":"2020-04-07","field_republish_html":"

\n\n
The silence of the owls
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No one knows exactly how the nocturnal hunters manage their whisper-soft flight, yet it is inspiring the design of quieter airplanes, fans and wind turbines
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By Dana Mackenzie
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4.7.2020
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\n
Every owl fancier has a story of the first time they heard an owl — or, rather, didn’t hear one. It’s unforgettable to see an enormous bird, whose wingspan can reach more than six feet, slipping through the air without even a whisper.
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Justin Jaworski’s first close encounter came at a flying exhibition at the Raptor Foundation near Cambridge, England. “They trained the owls to fly very close to the audience,” he says. “My first experience was of ducking to avoid a collision. I heard only a very slight swoosh after it passed.”
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Laboratory measurements have shown that the slight swoosh made by a barn owl is below the threshold of human hearing until the owl is about three feet away — a feat of stealth that biologists and engineers are far from completely understanding. But researchers from both disciplines are working to solve the riddle of silent flight — some with the aim of designing quieter fans, turbine blades and airplane wings.
\n\n
Such owl-inspired innovations can reduce noise by as much as 10 decibels, similar to the difference in noise between a passing truck and a passing car, Jaworski and Nigel Peake write in an overview in the 2020 Annual Review of Fluid Mechanics.
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Go gentle
\n\n
Jaworski, an engineer at Lehigh University in Pennsylvania, is hardly the first scientist to be captivated by the puzzle of silent owl flight. In 1934, Robert Rule Graham — a British pilot and bird connoisseur — called attention to three structures on owl wings that might account for the owls’ silence.
\n\n
More than 80 years later, his “three traits paradigm,” as Christopher Clark calls it, is still cited in many papers on owl wings. “He clearly knew birds very well, and he was an aeronautical engineer,” says Clark, an ornithologist at the University of California, Riverside. “Science was different in the 1930s. In our age of specialization, you don’t get that combination.”
\n\n
First, Graham pointed out an unusual structure called the “comb,” which literally looks like a comb projecting forward from the wing’s leading edge. Second, he noted that most of the owl wing is covered with a soft layer of velvety feathers. Finally, he observed that the feathers on the trailing edge of the wing form a ragged fringe.
\n\n
Most researchers still agree that the comb, the velvet and the fringe combine in some way to reduce noise, but the owl may have more tricks up its sleeve. “When all is said and done, I think we’ll have a number of mechanisms, including Graham’s,” says Clark.
\n\n
To explain how an owl suppresses noise, it would help to identify where the noise comes from in the first place. For an airplane coming in for a landing, a large part of the noise comes not from the engines but from the flow of air around the plane, especially the sound produced at the trailing edge of the wings. The turbulent air rushing past the exposed edges of the wings translates to the dull roar you hear as the plane flies overhead.
\n\n
One way to reduce this noise would be to make the trailing edge of the wing less hard, more porous and more flexible. This may be the function of the owl wing’s ragged fringes. Jaworski and Peake have mathematically calculated how engineers might use such porosity and elasticity to reduce noise, and how to quantify that diminished din.
\n\n
Those calculations are supported by wind-tunnel experiments: A variety of porous materials do dial down the noise. Work by Thomas Geyer at Brandenburg University of Technology in Germany has found that a poroelastic wing the size of an owl’s can be about 2 to 5 decibels quieter than a regular wing.
\n\n
However, says Geyer, the right porous material is crucial; in the wind-tunnel tests, some materials actually increased high-frequency noise. Measurements of owls in flight show that their wings mute only frequencies higher than 1,600 hertz (on a piano, two-and-a-half octaves above middle C). Since this is roughly where the range of rodent hearing begins, it’s the range that an owl would benefit most from suppressing as it hunts for a meal.
\n\n
Jaworski and Ian Clark (no relation to Christopher) of NASA’s Langley Research Center have attempted to mimic the owl’s velvet by covering a standard airfoil with various kinds of fabric. “The winning textile was a wedding veil,” says Jaworski. However, it may not be necessary to donate your nuptial accessories to science, because the researchers got even better results by attaching tiny plastic 3-D–printed “finlets” to the blades of a wind turbine.
\n\n
“Over a certain frequency range, we saw a 10-decibel noise reduction,” Jaworski says. “That may not sound like much, but in air acoustics, engineers fight over two or three decibels. Ten decibels is half as noisy. That’s a massive change for any technology.” Siemens, a manufacturer of wind turbines, has apparently been listening, and recently unveiled its second-generation “Dino Tail” turbines that have combs directly inspired by the owl wing.
\n\n
Feathery enigma
\n\n
Though owl wings are providing new insights into noise reduction for aeronautical engineering, engineers have had less success describing the physics of owl flight. According to ornithologist Clark, the engineers may not even have identified the most important source of noise in owl aviation.
\n\n
If you’re trying to build an owl, rather than a wind turbine or an airplane, you’ll notice several differences. Owls have feathers; airplanes don’t. Owls flap their wings; airplanes don’t. There’s a good reason that aeronautical engineers prefer stationary, solid wings to flapping, feathery ones: They are easier to understand.
\n\n
But if you are a biologist, to ignore flapping is to ignore a fundamental ingredient in avian flight, says Clark. As bird wings flap they change shape, and as they change shape the feathers rub against each other, causing noise. This noise is frictional, not aerodynamic, produced by the contact of solid against solid.
\n\n
In Clark’s view, the purpose of the owl’s velvet and the fringes is to reduce frictional noise between the feathers while flapping. Clark concedes that his argument would be moot if owls glided while hunting, but video evidence shows they do not: They flap when taking off, they flap when landing and they even flap when “coursing” for prey.
\n\n
And the fringes are not only on the trailing edge of the wing, where the aerodynamic theory would predict them to have the greatest noise-reducing benefit. Fringes also exist on the leading edges of the feathers, where they do not affect aerodynamic noise, as well on some feathers that are not even exposed to the airflow. This suggests that their purpose is not aerodynamic.
\n\n
Clark says that we may be asking the question backward. Instead of asking why owls are so quiet, we should ask why other birds are so loud. The answer is feathers. “Feathers are amazing structures, and probably the reason birds are so successful,” Clark says. But they come with an evolutionary cost: “If you’re going to build a wing out of feathers, they are going to produce frictional sound.” To become silent hunters, owls evolved special adaptations that reduce this disadvantage.
\n\n
Owls are not the only kind of bird that has solved this problem. Some species of Australian frogmouths have independently developed the same adaptations. These birds are also carnivorous and have wings that are soft and fluffy with combs and ragged fringes. In Graham’s day, people assumed that frogmouths were closely related to owls, but genomic analysis has proved that they are not. While less studied than owls, they too are silent flyers.
\n\n
“Evolution often takes a quirky path,” Clark says. “One way you can home in on the underlying mechanical principles, and tell them apart from quirks, is with convergent evolution.” When two unrelated animals have the same adaptation, it suggests that the feature confers a benefit — in this case, stealth.
\n\n
At present, there are two ways to understand owl flight: an engineering view informed by the equations of fluid motion and wind-tunnel experiments, and a biological view based on anatomy, behavior and genomics. A truly integrated story will probably require both. Even engineers realize that idealized studies based on rigid, unfeathered wings are not enough. It’s quite possible that the owl uses its feathers and small shape adjustments of the wing actively, rather than passively, to manipulate airflow. Engineers aren’t even close to understanding this process, which spans several size scales, from the barbs of the feathers to the individual feathers, to the entire wing.
\n\n
“What is missing to us is the microscopic point of view,” says Roi Gurka of Coastal Carolina University in South Carolina, whose experiments with flying owls have led to beautiful computer simulations of the flow field around a flapping owl wing. “I understand the wing,” he says, but understanding the role individual feather morphology plays in noise reduction is another matter.
\n\n
While the scientists debate, the barn owl will continue flying as it always has: its face as round and imperturbable as the moon, its ears trained on its next meal and its feathers treading gently on the air.
\n
\n\n
\n
\n
10.1146/knowable-040620-1
\n
\n\n
\n
Dana Mackenzie is a mathematician who went rogue and became a writer. His first book, written at age six or seven, was “The Adventures of Owl.”
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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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$\"Knowable$
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A quarter-century ago, social psychologist Anthony Greenwald of the University of Washington developed a test that exposed an uncomfortable aspect of the human mind: People have deep-seated biases of which they are completely unaware. And these hidden attitudes — known as implicit bias — influence the way we act toward each other, often with unintended discriminatory consequences.
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Since then, Greenwald and his main collaborators, Mahzarin Banaji and Brian Nosek, have used the implicit association test to measure how fast and accurately people associate different social groups with qualities like good and bad. They have developed versions of the test to measure things such as unconscious attitudes about race, gender stereotypes and bias against older people. Those tests have revealed just how pervasive implicit bias is. (Project Implicit offers public versions of the tests on its website here.)
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$\"Portrait$
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CREDIT: JAMES PROVOST (CC BY-ND)
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Psychologist Anthony Greenwald
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University of Washington
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The researchers' work has also shown how much implicit bias can shape social behavior and decision-making. Even people with the best intentions are influenced by these hidden attitudes, behaving in ways that can create disparities in hiring practices, student evaluations, law enforcement, criminal proceedings — pretty much anywhere people are making decisions that affect others. Such disparities can result from bias against certain groups, or favoritism toward other ones. Today, implicit bias is widely understood to be a cause of unintended discrimination that leads to racial, ethnic, socioeconomic and other inequalities.
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Discussions around the role of racism and implicit bias in the pattern of unequal treatment of racial minorities by law enforcement are intensifying following a roster of high-profile cases, most recently the killing of George Floyd. Floyd, an unarmed black man, died in Minneapolis last month after a white police officer pressed his knee into Floyd's neck for nearly nine minutes.
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As awareness of implicit bias and its effects has increased, so has interest in mitigating it. But that is much harder to do than scientists expected, as Greenwald told an audience in Seattle in February at the annual meeting of the American Association for the Advancement of Science. Greenwald, coauthor of an overview on implicit bias research in the 2020 Annual Review of Psychology, spoke with Knowable Magazine about what does and doesn’t work to counter the disparities that implicit bias can produce.
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This conversation has been edited for length and clarity.
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$\"Photo$
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At the Vienna Philharmonic, a musician prepares for a blind audition. The practice has helped counteract implicit bias against female players in the orchestra world.
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CREDIT: MARTIN KUBIK / VIENNA PHILHARMONIC
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How do you test for associations that people aren’t aware they have?
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The first implicit association test I created was one involving the names of flowers and insects, and words meaning things pleasant or unpleasant. You had to use left and right hands to classify them, tapping on a keyboard as they appeared on the screen. It was a very easy task when you had to use the right hand for both pleasant words and flower names, and the left hand for unpleasant words and insect names, because we typically think of flowers as pleasant and insects as unpleasant.
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But then the task is switched to force the opposite associations — one hand for insect names and pleasant words, and the other hand for flower names and unpleasant words. When I first tried that reversed form, my response time was about a third of a second slower compared to the first version. And in psychological work where you’re asking people to respond rapidly, a third of a second is like an eternity, indicating that some mental processes are going on in this version of the test that are not going on in the other.
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Then I replaced the flowers and insects with first names of men and women that are easily classified as European American or African American. For me, giving the same response to pleasant words and African American names took an eternity. But when it was the European American names and pleasant words with one hand, and the African American names and the unpleasant words with the other hand, that was something I could zip through. And that was a surprise to me. I would have described myself at that point as someone who is lacking in biases or prejudices of a racial nature. I probably had some biases that I would confess to, but I actually didn’t think I had that one.
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How widespread is implicit bias?
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That particular implicit bias, the one involving black-white race, shows up in about 70 percent to 75 percent of all Americans who try the test. It shows up more strongly in white Americans and Asian Americans than in mixed-race or African Americans. African Americans, you’d think, might show just the reverse effect — that it would be easy for them to put African American together with pleasant and white American together with unpleasant. But no, African Americans show, on average, neither direction of bias on that task.
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Most people have multiple implicit biases they aren’t aware of. It is much more widespread than is generally assumed.
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Is implicit bias a factor in the pattern of police violence such as that seen in the killing of George Floyd on May 25, which sparked the ongoing protests across the country?
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The problems surfacing in the wake of George Floyd’s death include all forms of bias, ranging from implicit bias to structural bias built into the operation of police departments, courts and governments, to explicit, intended bias, to hate crime.
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The best theory of how implicit bias works is that it shapes conscious thought, which in turn guides judgments and decisions. The ABC News correspondent Pierre Thomas expressed this very well recently by saying, “Black people feel like they are being treated as suspects first and citizens second.” When a black person does something that is open to alternative interpretations, like reaching into a pocket or a car’s glove compartment, many people — not just police officers — may think first that it’s possibly dangerous. But that wouldn’t happen in viewing a white person do exactly the same action. The implications of conscious judgment being shaped in this way by an automatic, implicit process of which the perceiver is unaware can assume great importance in outcomes of interactions with police.
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Do the diversity or implicit bias training programs used by companies and institutions like Starbucks and the Oakland Police Department help reduce bias?
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I’m at the moment very skeptical about most of what’s offered under the label of implicit bias training, because the methods being used have not been tested scientifically to indicate that they are effective. And they’re using it without trying to assess whether the training they do is achieving the desired results.
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I see most implicit bias training as window dressing that looks good both internally to an organization and externally, as if you’re concerned and trying to do something. But it can be deployed without actually achieving anything, which makes it in fact counterproductive. After 10 years of doing this stuff and nobody reporting data, I think the logical conclusion is that if it was working, we would have heard about it.
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$\"This$
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In 2018, Starbucks closed 8,000 stores for a few hours to run an anti-bias training course for employees. The effort followed an incident at this café in Philadelphia, during which an employee called police on two black men who were inside the store but had not ordered anything, and the men were arrested. There’s no evidence that such training is effective.
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CREDIT: AP PHOTO / RON TODT
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Can you tell us about some of the approaches meant to reduce bias that haven’t worked?
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I’ll give you several examples of techniques that have been tried with the assumption that they would achieve what’s sometimes called debiasing or reducing implicit biases. One is exposure to counter-stereotypic examples, like seeing examples of admirable scientists or entertainers or others who are African American alongside examples of whites who are mass murderers. And that produces an immediate effect. You can show that it will actually affect a test result if you measure it within about a half-hour. But it was recently found that when people started to do these tests with longer delays, a day or more, any beneficial effect appears to be gone.
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$\"Photo$
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CREDIT: PHOTOGRAPHEE.EU / SHUTTERSTOCK
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Implicit bias is pervasive
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Hundreds of studies have revealed the workings of implicit bias in a wide range of settings. Here are a few examples that demonstrate how it can occur in just about any situation in which people make decisions that affect other people.
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In law enforcement: A study found that police in New York City stopped black and Hispanic pedestrians more often than white pedestrians, and a study in Oakland, California, found that black men were far more likely to be handcuffed, searched or arrested than anyone else when stopped by police.
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In the office: Hiring managers were less likely to invite an obese applicant for an interview, people see older workers as less valuable and bias against Arab-Muslim men influenced hiring decisions in Sweden.
\n\n
In the courtroom: Studies found that implicit bias against African Americans affects almost every step in the judicial system, from prosecutors deciding which cases to charge to judges handing down decisions.
\n\n
In the classroom: Public high school teachers in Sweden gave higher test scores to students with Swedish backgrounds than those with foreign ones, while American psychology students rated young male teachers higher than older men, as well as younger and older women.
\n\n
In the hospital: Doctors were more likely to offer a blood-clot-busting treatment to white patients with acute coronary disease than to black patients with the same symptoms, and nursing students showed a bias against overweight patients.
\n\n
In a pandemic? A study showed that when people feel especially vulnerable to infectious disease, their negative attitudes toward older adults may be heightened.
\n\n
—Betsy Mason
\n
\n
Other strategies that haven’t been very effective include just encouraging people to have a strong intention not to allow themselves to be biased. Or trainers will suggest people do something that they may call “thinking slow” or pausing before making decisions. Another method that has been tried is meditation. And another strategy is making people aware that they have implicit biases or that implicit biases are pervasive in the population. All these may seem reasonable, but there’s no empirical demonstration that they work.
\n\n
It’s surprising to me that making people aware of their bias doesn't do anything to mitigate it. Why do you think that is?
\n\n
I think you’re right, it is surprising. The mechanisms by which our brains form associations and acquire them from the cultural environment evolved over long periods of time, during which people lived in an environment that was consistent. They were not actually likely to acquire something that they would later have to unlearn, because the environment wasn’t going to change. So there may have been no evolutionary pressure for the human brain to develop a method of unlearning the associations.
\n\n
I don’t know why we have not succeeded in developing effective techniques to reduce implicit biases as they are measured by the implicit association test. I’m not prepared to say that we’re never going to be able to do it, but I will say that people have been looking for a long time, ever since the test was introduced, which is over 20 years now, and this hasn’t been solved yet.
\n\n
Is there anything that does work?
\n\n
I think that a lot can be achieved just by collecting data to document disparities that are occurring as a result of bias. And maybe an easy example is police operations, although it can be applied in many settings. Most police departments keep data on what we know as profiling, though they don’t like to call it that. It’s what happens in a traffic stop or a pedestrian stop — for example, the stop-and-frisk policy that former New York City Mayor Michael Bloomberg has taken heat for. The data of the New York City Police Department for stops of black and white pedestrians and drivers were analyzed, and it was very clear that there were disparities.
\n\n
Once you know where the problem is that has to be solved, it’s up to the administrators to figure out ways to understand why and how this is happening. Is it happening in just some parts of the city? Is it that the police are just operating more in Harlem than in the white neighborhoods?
\n\n
And once you know what’s happening, the next step is what I call discretion elimination. This can be applied when people are making decisions that involve subjective judgment about a person. This could be police officers, employers making hiring or promotion decisions, doctors deciding on a patient’s treatment, or teachers making decisions about students’ performance. When those decisions are made with discretion, they are likely to result in unintended disparities. But when those decisions are made based on predetermined, objective criteria that are rigorously applied, they are much less likely to produce disparities.
\n\n
Is there evidence that discretion elimination works?
\n\n
What we know comes from the rare occasions in which the effects of discretion elimination have been recorded and reported. The classic example of this is when major symphony orchestras in the United States started using blind auditions in the 1970s. This was originally done because musicians thought that the auditions were biased in favor of graduates of certain schools like the Juilliard School. They weren’t concerned about gender discrimination.
\n\n
But as soon as auditions started to be made behind screens so the performer could not be seen, the share of women hired as instrumentalists in major symphony orchestras rose from around 10 percent or 20 percent before 1970 to about 40 percent. This has had a major impact on the rate at which women have become instrumentalists in major symphony orchestras.
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$\"Graphs$
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Implementing blind auditions for US symphony orchestras in the 1970s resulted in a sizable increase in the proportion of women being hired as instrumentalists. This graph shows that for four of the country's five top orchestras, the percentage of new hires that were women jumped from around 10 percent before the change to around 40 percent by the early 1990s. (Five-year moving average shown.)
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But these data-collection and discretion-elimination strategies aren’t commonly used?
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Not nearly as often as they could. For example, instructors can usually arrange to grade almost anything that a student does without knowing the identity of the student. In an electronic age when you don’t learn to recognize people’s handwriting, instructors can grade essays without the students’ names on them. I used that approach when I was last grading undergraduates in courses. It’s easy to use, but it’s often not used at all.
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And in many other circumstances it is possible to evaluate performance without knowing the identity of the person being evaluated. But employers and others rarely forgo the opportunity to know the identity of the person they’re evaluating.
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$\"Photo$
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Over the past decades, blind auditions have helped more women secure spots in professional orchestras, presumably by battling biases against female musicians.
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CREDIT: EVERT ELZINGA / GETTY IMAGES
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Can artificial intelligence play a role?
\n\n
People are starting to apply artificial intelligence to the task by mining historical records of past employment decisions. This is a way of taking the decisions that involve human discretion and putting them into the hands of a machine. The idea is to develop algorithms that identify promising applicants by matching their qualities to those of past applicants who turned out to be successful employees.
\n\n
I think it’s a great thing to try. But so far, efforts with AI have not succeeded, because the historical databases used to develop the algorithms to make these decisions turn out to be biased, too. They incorporate the biases of past decision-makers. One example is how biases affect facial-recognition technology, which inadvertently categorizes African American faces or Asian faces as criminal more often than white faces.
\n\n
$\"\"$
\n\n
\n
Explore Knowable’s coronavirus coverage
\n
\n
This is a problem that computer scientists are trying to cope with, but some of the people in AI that I have spoken to seem not so optimistic that this will be at all easy to do. But I do think that ultimately — and it might take a while — the biases may be expunged more readily from AI decision algorithms than from human decision-making.
\n\n
Could more be done at the level of an individual company or department?
\n\n
To help prevent unintended discrimination, the leaders of organizations need to decide to track data to see where disparities are occurring. When they discover disparities, they need to try to make changes and then look at the next cycle of data to see if those changes are improving things.
\n\n
Obviously, it’s easier for them not to do those things. In some cases there’s a cost to doing them. And they may think it’s like opening up Pandora’s box if they look closely at the data. I think this is true of many police departments. They’re bound to find things that they’d rather not see.
\n\n","field_all_authors":"
By Betsy Mason 06.04.2020
\n\n","field_author_bios":"
\n
Betsy Mason is a freelance journalist based in the San Francisco Bay Area who specializes in science and cartography. She is the coauthor, with Greg Miller, of All Over the Map: A Cartographic Odyssey (National Geographic, 2018).
\n
\n\n","field_banner_alt":"A 2012 photo shows a crowd of marchers, including two young black boys, walking down 5th Avenue in New York City. Their sign reads: “Stop Racial Profiling. End Stop & Frisk.”","field_banner_title":"Biased policy","field_credit":"
CREDIT: FRANCES ROBERTS / ALAMY STOCK PHOTO
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Q&A — Psychologist Anthony Greenwald
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Curbing implicit bias: what works and what doesn't
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Psychologists have yet to find a way to diminish hidden prejudice, but they do have strategies for thwarting discrimination
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By Betsy Mason
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6.4.2020
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A quarter-century ago, social psychologist Anthony Greenwald of the University of Washington developed a test that exposed an uncomfortable aspect of the human mind: People have deep-seated biases of which they are completely unaware. And these hidden attitudes — known as implicit bias — influence the way we act toward each other, often with unintended discriminatory consequences.
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Since then, Greenwald and his main collaborators, Mahzarin Banaji and Brian Nosek, have used the implicit association test to measure how fast and accurately people associate different social groups with qualities like good and bad. They have developed versions of the test to measure things such as unconscious attitudes about race, gender stereotypes and bias against older people. Those tests have revealed just how pervasive implicit bias is. (Project Implicit offers public versions of the tests on its website here.)
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The researchers' work has also shown how much implicit bias can shape social behavior and decision-making. Even people with the best intentions are influenced by these hidden attitudes, behaving in ways that can create disparities in hiring practices, student evaluations, law enforcement, criminal proceedings — pretty much anywhere people are making decisions that affect others. Such disparities can result from bias against certain groups, or favoritism toward other ones. Today, implicit bias is widely understood to be a cause of unintended discrimination that leads to racial, ethnic, socioeconomic and other inequalities.
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Discussions around the role of racism and implicit bias in the pattern of unequal treatment of racial minorities by law enforcement are intensifying following a roster of high-profile cases, most recently the killing of George Floyd. Floyd, an unarmed black man, died in Minneapolis last month after a white police officer pressed his knee into Floyd's neck for nearly nine minutes.
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As awareness of implicit bias and its effects has increased, so has interest in mitigating it. But that is much harder to do than scientists expected, as Greenwald told an audience in Seattle in February at the annual meeting of the American Association for the Advancement of Science. Greenwald, coauthor of an overview on implicit bias research in the 2020 Annual Review of Psychology, spoke with Knowable Magazine about what does and doesn’t work to counter the disparities that implicit bias can produce.
\n\n
This conversation has been edited for length and clarity.
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How do you test for associations that people aren’t aware they have?
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The first implicit association test I created was one involving the names of flowers and insects, and words meaning things pleasant or unpleasant. You had to use left and right hands to classify them, tapping on a keyboard as they appeared on the screen. It was a very easy task when you had to use the right hand for both pleasant words and flower names, and the left hand for unpleasant words and insect names, because we typically think of flowers as pleasant and insects as unpleasant.
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But then the task is switched to force the opposite associations — one hand for insect names and pleasant words, and the other hand for flower names and unpleasant words. When I first tried that reversed form, my response time was about a third of a second slower compared to the first version. And in psychological work where you’re asking people to respond rapidly, a third of a second is like an eternity, indicating that some mental processes are going on in this version of the test that are not going on in the other.
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Then I replaced the flowers and insects with first names of men and women that are easily classified as European American or African American. For me, giving the same response to pleasant words and African American names took an eternity. But when it was the European American names and pleasant words with one hand, and the African American names and the unpleasant words with the other hand, that was something I could zip through. And that was a surprise to me. I would have described myself at that point as someone who is lacking in biases or prejudices of a racial nature. I probably had some biases that I would confess to, but I actually didn’t think I had that one.
\n\n
How widespread is implicit bias?
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That particular implicit bias, the one involving black-white race, shows up in about 70 percent to 75 percent of all Americans who try the test. It shows up more strongly in white Americans and Asian Americans than in mixed-race or African Americans. African Americans, you’d think, might show just the reverse effect — that it would be easy for them to put African American together with pleasant and white American together with unpleasant. But no, African Americans show, on average, neither direction of bias on that task.
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Most people have multiple implicit biases they aren’t aware of. It is much more widespread than is generally assumed.
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Is implicit bias a factor in the pattern of police violence such as that seen in the killing of George Floyd on May 25, which sparked the ongoing protests across the country?
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The problems surfacing in the wake of George Floyd’s death include all forms of bias, ranging from implicit bias to structural bias built into the operation of police departments, courts and governments, to explicit, intended bias, to hate crime.
\n\n
The best theory of how implicit bias works is that it shapes conscious thought, which in turn guides judgments and decisions. The ABC News correspondent Pierre Thomas expressed this very well recently by saying, “Black people feel like they are being treated as suspects first and citizens second.” When a black person does something that is open to alternative interpretations, like reaching into a pocket or a car’s glove compartment, many people — not just police officers — may think first that it’s possibly dangerous. But that wouldn’t happen in viewing a white person do exactly the same action. The implications of conscious judgment being shaped in this way by an automatic, implicit process of which the perceiver is unaware can assume great importance in outcomes of interactions with police.
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Do the diversity or implicit bias training programs used by companies and institutions like Starbucks and the Oakland Police Department help reduce bias?
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I’m at the moment very skeptical about most of what’s offered under the label of implicit bias training, because the methods being used have not been tested scientifically to indicate that they are effective. And they’re using it without trying to assess whether the training they do is achieving the desired results.
\n\n
I see most implicit bias training as window dressing that looks good both internally to an organization and externally, as if you’re concerned and trying to do something. But it can be deployed without actually achieving anything, which makes it in fact counterproductive. After 10 years of doing this stuff and nobody reporting data, I think the logical conclusion is that if it was working, we would have heard about it.
\n\n
Can you tell us about some of the approaches meant to reduce bias that haven’t worked?
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I’ll give you several examples of techniques that have been tried with the assumption that they would achieve what’s sometimes called debiasing or reducing implicit biases. One is exposure to counter-stereotypic examples, like seeing examples of admirable scientists or entertainers or others who are African American alongside examples of whites who are mass murderers. And that produces an immediate effect. You can show that it will actually affect a test result if you measure it within about a half-hour. But it was recently found that when people started to do these tests with longer delays, a day or more, any beneficial effect appears to be gone.
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CREDIT: PHOTOGRAPHEE.EU / SHUTTERSTOCK
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Implicit bias is pervasive
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Hundreds of studies have revealed the workings of implicit bias in a wide range of settings. Here are a few examples that demonstrate how it can occur in just about any situation in which people make decisions that affect other people.
\n\n
In law enforcement: A study found that police in New York City stopped black and Hispanic pedestrians more often than white pedestrians, and a study in Oakland, California, found that black men were far more likely to be handcuffed, searched or arrested than anyone else when stopped by police.
\n\n
In the office: Hiring managers were less likely to invite an obese applicant for an interview, people see older workers as less valuable and bias against Arab-Muslim men influenced hiring decisions in Sweden.
\n\n
In the courtroom: Studies found that implicit bias against African Americans affects almost every step in the judicial system, from prosecutors deciding which cases to charge to judges handing down decisions.
\n\n
In the classroom: Public high school teachers in Sweden gave higher test scores to students with Swedish backgrounds than those with foreign ones, while American psychology students rated young male teachers higher than older men, as well as younger and older women.
\n\n
In the hospital: Doctors were more likely to offer a blood-clot-busting treatment to white patients with acute coronary disease than to black patients with the same symptoms, and nursing students showed a bias against overweight patients.
\n\n
In a pandemic? A study showed that when people feel especially vulnerable to infectious disease, their negative attitudes toward older adults may be heightened.
\n\n
—Betsy Mason
\n
\n
\n\n
Other strategies that haven’t been very effective include just encouraging people to have a strong intention not to allow themselves to be biased. Or trainers will suggest people do something that they may call “thinking slow” or pausing before making decisions. Another method that has been tried is meditation. And another strategy is making people aware that they have implicit biases or that implicit biases are pervasive in the population. All these may seem reasonable, but there’s no empirical demonstration that they work.
\n\n
It’s surprising to me that making people aware of their bias doesn't do anything to mitigate it. Why do you think that is?
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I think you’re right, it is surprising. The mechanisms by which our brains form associations and acquire them from the cultural environment evolved over long periods of time, during which people lived in an environment that was consistent. They were not actually likely to acquire something that they would later have to unlearn, because the environment wasn’t going to change. So there may have been no evolutionary pressure for the human brain to develop a method of unlearning the associations.
\n\n
I don’t know why we have not succeeded in developing effective techniques to reduce implicit biases as they are measured by the implicit association test. I’m not prepared to say that we’re never going to be able to do it, but I will say that people have been looking for a long time, ever since the test was introduced, which is over 20 years now, and this hasn’t been solved yet.
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Is there anything that does work?
\n\n
I think that a lot can be achieved just by collecting data to document disparities that are occurring as a result of bias. And maybe an easy example is police operations, although it can be applied in many settings. Most police departments keep data on what we know as profiling, though they don’t like to call it that. It’s what happens in a traffic stop or a pedestrian stop — for example, the stop-and-frisk policy that former New York City Mayor Michael Bloomberg has taken heat for. The data of the New York City Police Department for stops of black and white pedestrians and drivers were analyzed, and it was very clear that there were disparities.
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Once you know where the problem is that has to be solved, it’s up to the administrators to figure out ways to understand why and how this is happening. Is it happening in just some parts of the city? Is it that the police are just operating more in Harlem than in the white neighborhoods?
\n\n
And once you know what’s happening, the next step is what I call discretion elimination. This can be applied when people are making decisions that involve subjective judgment about a person. This could be police officers, employers making hiring or promotion decisions, doctors deciding on a patient’s treatment, or teachers making decisions about students’ performance. When those decisions are made with discretion, they are likely to result in unintended disparities. But when those decisions are made based on predetermined, objective criteria that are rigorously applied, they are much less likely to produce disparities.
\n\n
Is there evidence that discretion elimination works?
\n\n
What we know comes from the rare occasions in which the effects of discretion elimination have been recorded and reported. The classic example of this is when major symphony orchestras in the United States started using blind auditions in the 1970s. This was originally done because musicians thought that the auditions were biased in favor of graduates of certain schools like the Juilliard School. They weren’t concerned about gender discrimination.
\n\n
But as soon as auditions started to be made behind screens so the performer could not be seen, the share of women hired as instrumentalists in major symphony orchestras rose from around 10 percent or 20 percent before 1970 to about 40 percent. This has had a major impact on the rate at which women have become instrumentalists in major symphony orchestras.
\n\n
But these data-collection and discretion-elimination strategies aren’t commonly used?
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Not nearly as often as they could. For example, instructors can usually arrange to grade almost anything that a student does without knowing the identity of the student. In an electronic age when you don’t learn to recognize people’s handwriting, instructors can grade essays without the students’ names on them. I used that approach when I was last grading undergraduates in courses. It’s easy to use, but it’s often not used at all.
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And in many other circumstances it is possible to evaluate performance without knowing the identity of the person being evaluated. But employers and others rarely forgo the opportunity to know the identity of the person they’re evaluating.
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Can artificial intelligence play a role?
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People are starting to apply artificial intelligence to the task by mining historical records of past employment decisions. This is a way of taking the decisions that involve human discretion and putting them into the hands of a machine. The idea is to develop algorithms that identify promising applicants by matching their qualities to those of past applicants who turned out to be successful employees.
\n\n
I think it’s a great thing to try. But so far, efforts with AI have not succeeded, because the historical databases used to develop the algorithms to make these decisions turn out to be biased, too. They incorporate the biases of past decision-makers. One example is how biases affect facial-recognition technology, which inadvertently categorizes African American faces or Asian faces as criminal more often than white faces.
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Explore Knowable’s coronavirus coverage
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This is a problem that computer scientists are trying to cope with, but some of the people in AI that I have spoken to seem not so optimistic that this will be at all easy to do. But I do think that ultimately — and it might take a while — the biases may be expunged more readily from AI decision algorithms than from human decision-making.
\n\n
Could more be done at the level of an individual company or department?
\n\n
To help prevent unintended discrimination, the leaders of organizations need to decide to track data to see where disparities are occurring. When they discover disparities, they need to try to make changes and then look at the next cycle of data to see if those changes are improving things.
\n\n
Obviously, it’s easier for them not to do those things. In some cases there’s a cost to doing them. And they may think it’s like opening up Pandora’s box if they look closely at the data. I think this is true of many police departments. They’re bound to find things that they’d rather not see.
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10.1146/knowable-060320-1
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Betsy Mason is a freelance journalist based in the San Francisco Bay Area who specializes in science and cartography. She is the coauthor, with Greg Miller, of All Over the Map: A Cartographic Odyssey (National Geographic, 2018).
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This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
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$\"Knowable$
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With many states and towns lifting strict stay-at-home orders, people are faced with a growing number of new decisions. Mundane logistical questions — Should I go get my hair cut? When can I picnic with friends? What should I wear to the hardware store? — during the Covid-19 pandemic carry implications for personal and public health, in some cases life-or-death ones.
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Explore Knowable’s coronavirus coverage
\n
\n
When multiplied through the population, seemingly small decisions have the power to either dramatically slow or accelerate this pandemic. It puts the nuances of decision-making front and center.
We might like to think that our behavioral choices, especially around something so important as a global pandemic, are based purely on the best information we have.
But that isn’t the case, say experts in behavioral science and social psychology. In fact, we are all susceptible to biases that push and pull our brains in invisible ways.
\n
“The idea is if people just have information, then they will make the rational choice. And that’s just wrong.”
\n\n \n Damon Centola\n \n
This happens in part because of overconfidence in our ability to know why we make the choices we do. “There’s a powerful belief in the value of introspection, which much of social psychology and psychological science has shown is a mistake,” says Jennifer Lerner, a psychologist at the Harvard Kennedy School. “We are not good at understanding what our brains are doing…. Even things that are conscious are affected by nonconscious factors in ways we don’t know.”
Her work and that of others can help us better understand how our own decision-making processes are being affected in these unprecedented times — and perhaps how we can inoculate ourselves and others against unwise decisions.
Here are five factors that can sway how we choose to behave during the pandemic:
The bias of the here and now
In a lot of ways, we are creatures of the present. “We tend to make decisions based on the information that is most resonant, closest at hand, most recent,” says Nicholas King, a biomedical ethicist at McGill University in Montreal. So, if you are lucky enough to not know anyone sickened with Covid-19, you might not be prompted to take rigorous precautions.
It’s easier, King says, to look out the window and see what is going on around you than to dive into epidemiological models and data-based projections.
\n
\n $\"In$
\n\n
Social distancing and wearing masks are two public health choices facing people during the Covid-19 pandemic. In May, women gathered for a small, outdoor celebration for a friend’s birthday in Santa Monica, California, with one choosing to wear a mask.
\n \n \n
CREDIT: JASON ARMOND / © 2020 LOS ANGELES TIMES. USED WITH PERMISSION.
\n \n \n
As another part of this preference for the present, we tend to evaluate our behavior on what we perceive as the “status quo” — even if that “new normal” is radically different from what we were used to just months ago, King says.
This tendency can backfire, however, because we also have a bias toward action.
It’s not unlike feeling sick and going to the doctor. Often the best course of action is not a drug or procedure but “watchful waiting.” To a lot of people, though, that is the hardest pill to swallow. Instead of being the sound, evidence-based choice, watchful waiting feels like, “we should be doing something, but instead we’re doing nothing,” King says.
In the pandemic, our new status quo — of physical distancing — has been that sort of watchful waiting period. And now people want to take action and make different decisions about their preferred behavior. “I think a lot of the push to reopening is sort of this idea that we need to do something,” King says. Yet back in March, he points out, “doing something” was implementing physical distancing measures — the very thing that some people interpret as inaction today.
Colored by emotions
Although we might think of ourselves as rational, research shows that even the most minor of choices can be colored by our mood.
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“Emotions have a profound effect on the process with which people make decisions,” says Lerner, who coauthored an article about emotion and decision-making in the 2015 Annual Review of Psychology. Especially when dealing with incidental emotions — a kind of background feeling unrelated to the decision at hand — we are often unaware of how it influences our thinking.
For example, Lerner and colleagues have found that anger — not uncommon when our lives are affected by a force outside our control — tends to lead to less thoughtful analysis. “Angry people don’t question themselves,” she says. “They don’t say, ‘Gosh, I wonder if I’m right about this. I’m not sure if I’m using the right information.’” And that can lead people to make less-than-ideal choices.
Perhaps even more prevalent than anger, these days, is sadness, as people lose not just loved ones or their own health but also income and freedom of movement. Unlike anger, though, “sadness actually makes you think more deeply” and can help to process information in a more robust, systematic way, Lerner says.
Lerner’s work has also shown that sadness can lead to poor financial decisions. “Sadness arising from loss triggers an implicit goal of replacing that loss,” she says. In experiments described in 2008 in Psychological Science, she and her colleagues found that study participants prompted into a sad mood were more willing to pay overly high prices to buy things immediately than those who were in a neutral mood. “So there’s a real risk, when you’re sad, of over-shopping and paying too much for things,” Lerner notes. This is especially troubling during a recession spurred by a loss-filled event like a global pandemic.
Fear has also been shown to be an influencer: Research done after 9/11 found that fear heightened people’s perception of risk, and so, too, their intentions to take precautions.
Searching for certainty
Another prevailing force right now is extreme uncertainty, which, as King puts it, “sucks.” This instability can lead people to seek narrow ranges of information in a quest for confirmation of their perspectives.
\n
“One of the most important things that we all need to do is to become more comfortable with uncertainty. Relying on false certainty leads to a lot of bad decisions.”
\n\n \n Nicholas King\n \n
“Confirmation bias is a way of minimizing uncertainty: Because you’re only choosing evidence that confirms your preexisting world view, you can maintain a certain confidence level of what you already believe,” King says.
This, like anger, leads people to be less considerate of potentially wiser perspectives and options for behavior, such as weighing multiple sources of information about the safety of large gatherings like protests or religious services.
Adding to the trouble, this drive often perpetuates misguided certainty that can lead to similarly misguided behavioral choices. “In policy arenas and personal life — even in science — the person who declares things with certainty tends to garner more attention and a lot more trust than the person who expresses uncertainty,” King says.
Which, he says, gets things exactly backward.
“I trust the person who honestly and transparently discusses the uncertainties involved … much more,” King says. “One of the most important things that we all need to do is to become more comfortable with uncertainty. Relying on false certainty leads to a lot of bad decisions.”
Peer pressure
We rarely make decisions in a vacuum — even if they seem entirely personal. And we are influenced by those around us more than we might think.
A virus or rumor can transmit through simple contact. But for a more complex social behavior, like wearing a mask to protect others, the dynamics are much more complicated, explains Damon Centola, who studies social networks and social epidemiology at the Annenberg School for Communication at the University of Pennsylvania.
In this case, social networks act more like prisms, as Centola described in the 2019 Annual Review of Sociology. These networks actually “shape how we view the information we’re receiving, how responsive we are to the new behaviors we’re exposed to, and whether or not we accept them,” he says. “The idea is if people just have information, then they will make the rational choice. And that’s just wrong.”
As much as any recommendations from the CDC or the county health department, your peers affect the choices you make.
\n
\n $\"Photo$
\n\n
As lockdowns ease, many are facing difficult decisions about daily life — from seeing friends to venturing out to public spaces. Those decisions are influenced by a number of factors of which we are often not aware.
\n \n \n
CREDIT: CATALIN STOICA / ALAMY STOCK PHOTO
\n \n \n
Centola gives the example of physical distancing early on in the pandemic. If you were the only one in your office to decide to not attend a meeting — or the only one of your friends to skip a dinner party — in an effort to physically distance, it might have had adverse professional or social effects. But if most of your colleagues (or friends) established the norm of not attending in-person gatherings, that decision becomes the default. The same might go for wearing masks in your neighborhood.
This lesson has takeaways for everyone up the decision-making chain. “This is a really important factor when we think about behavioral diffusion and really any public health policy that involves this kind of decision-making process,” Centola says.
When healthy is easy
To understand how to help people make better decisions in this pandemic, scientists are looking to insights gained from previous work on pro-social health behaviors. Gretchen Chapman, who studies social and decision sciences at Carnegie Mellon University, has done decades of research in this field, such as on people’s decisions to get vaccines.
“Trying to change people’s beliefs and feelings about vaccination is not very effective — it’s more effective to intervene on the behavior directly by making the behavior easy,” she says. (This can be as simple as automatically scheduling flu shot appointments.)
Any way to make the desired behavior decision as frictionless as possible is key, Chapman says. If you want people to decide to mostly avoid going to grocery stores, “grocery delivery should be really easy and accessible,” she says. Or if you’re trying to ensure mask wearing, have disposable masks available for people before they enter a store.
\n
\n $\"Photo$
\n\n
A clear finding of health behavior research is that making healthy choices easy and convenient leads more people to adopt those behaviors. Mask-wearing is a prime example. In Latvia in May, a public vending machine offers disposable protective face masks.
\n \n \n
CREDIT: PICTURE ALLIANCE / GETTY IMAGES
\n \n \n
What also helps people make decisions about new behaviors is simply seeing massive change in their environment. As Chapman notes from her home in Pittsburgh, where springtime birds chirp in the background, “just looking around at my environment, I would never guess that this was a serious situation. But the governor closed public schools, and all the other universities have closed — I kind of sit up and take notice. I’m, like, ‘Oh, wow, I guess this must be a really big deal.’”
Centola has researched adoption of other highly visible pro-social behaviors, such as the decision to put solar panels on your house. Many government programs have tried information campaigns and financial incentives. But most effective were programs that installed panels on a certain number of houses per neighborhood, creating a contagion dynamic leading neighbors to follow the new norm.
What we can learn – and what we can do better
A better understanding of how we make decisions can not only help us make better ones, but it can also help experts learn how to nudge us toward healthy behaviors.
Chapman and colleagues, for example, are studying how different messages — straight informational versus one that includes an estimate of how popular something is (how many Americans are wearing masks, for example) — change people’s intended behavior, such as their plans to physically distance or wear a mask. She expects that whom the messaging depicts will also influence the results: “If they learn that other people like them in their neighborhood are wearing masks,” they may be more likely to plan to do the same, she says.
One grand challenge of public-health decision making is helping everyone make the best choices. As Centola says, where he lives in Philadelphia, a lot of people work jobs they cannot do from home. So there are large networks of people whose lives, by necessity, haven’t changed all that much.
“There’s a kind of equity issue built into a lot of the public-health campaigns,” he says. More affluent networks of people have the luxury of being able to shelter at home more or less full-time and act on high-level information, he notes. Whereas, “disadvantaged populations, even if they’re hearing that information, it’s just not as relevant to their circumstances, it’s not manageable. And so it gets ignored.” That can also be reinforced by social networks, Centola says. In this case, “inequities are reinforced by what they see their peers doing.”
One of the big challenges throughout the pandemic has, of course, been figuring out what the best decisions even are, given the unknowns about the Covid-19 virus. Good decisions may seem like moving targets as official recommendations keep changing, Chapman says. Which is all the more reason to be aware of not just the information we are getting, but also the actions we choose to take — or not.
\n","field_all_authors":"
\n \n \n \n By\n\n \n Katherine Harmon Courage\n \n \n \n \n 05.26.2020\n
\n","field_ar_article":{"arguments":[]},"field_author_bios":"
\n
Katherine Harmon Courage is a freelance journalist, Scientific American contributor and author of the books Cultured and Octopus! You can follow her on Twitter for more pandemic — and octopus — coverage at @KHCourage or www.katherinecourage.com.
\n
\n","field_banner_alt":"Illustration shows the Thinker contemplating while coronavirus particles drift by.","field_banner_title":"Decision-making","field_caption":"
People don’t make entirely rational decisions at any time, much less during a pandemic.
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CREDIT: KNOWABLE MAGAZINE, STATUE FROM NATHAN HUGHES HAMILTON
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Explained
\n
How we make decisions during a pandemic
\n
From mask wearing to physical distancing, individuals wield a lot of power in how the coronavirus outbreak plays out. Behavioral experts reveal what might be prompting people to act — or not.
\n
\n By Katherine Harmon Courage \n \n
\n
5.26.2020
\n
With many states and towns lifting strict stay-at-home orders, people are faced with a growing number of new decisions. Mundane logistical questions — Should I go get my hair cut? When can I picnic with friends? What should I wear to the hardware store? — during the Covid-19 pandemic carry implications for personal and public health, in some cases life-or-death ones.
Explore Knowable’s coronavirus coverage
When multiplied through the population, seemingly small decisions have the power to either dramatically slow or accelerate this pandemic. It puts the nuances of decision-making front and center.
We might like to think that our behavioral choices, especially around something so important as a global pandemic, are based purely on the best information we have.
But that isn’t the case, say experts in behavioral science and social psychology. In fact, we are all susceptible to biases that push and pull our brains in invisible ways.
“The idea is if people just have information, then they will make the rational choice. And that’s just wrong.”
Damon Centola
This happens in part because of overconfidence in our ability to know why we make the choices we do. “There’s a powerful belief in the value of introspection, which much of social psychology and psychological science has shown is a mistake,” says Jennifer Lerner, a psychologist at the Harvard Kennedy School. “We are not good at understanding what our brains are doing…. Even things that are conscious are affected by nonconscious factors in ways we don’t know.”
Her work and that of others can help us better understand how our own decision-making processes are being affected in these unprecedented times — and perhaps how we can inoculate ourselves and others against unwise decisions.
Here are five factors that can sway how we choose to behave during the pandemic:
The bias of the here and now
In a lot of ways, we are creatures of the present. “We tend to make decisions based on the information that is most resonant, closest at hand, most recent,” says Nicholas King, a biomedical ethicist at McGill University in Montreal. So, if you are lucky enough to not know anyone sickened with Covid-19, you might not be prompted to take rigorous precautions.
It’s easier, King says, to look out the window and see what is going on around you than to dive into epidemiological models and data-based projections.
As another part of this preference for the present, we tend to evaluate our behavior on what we perceive as the “status quo” — even if that “new normal” is radically different from what we were used to just months ago, King says.
This tendency can backfire, however, because we also have a bias toward action.
It’s not unlike feeling sick and going to the doctor. Often the best course of action is not a drug or procedure but “watchful waiting.” To a lot of people, though, that is the hardest pill to swallow. Instead of being the sound, evidence-based choice, watchful waiting feels like, “we should be doing something, but instead we’re doing nothing,” King says.
In the pandemic, our new status quo — of physical distancing — has been that sort of watchful waiting period. And now people want to take action and make different decisions about their preferred behavior. “I think a lot of the push to reopening is sort of this idea that we need to do something,” King says. Yet back in March, he points out, “doing something” was implementing physical distancing measures — the very thing that some people interpret as inaction today.
Colored by emotions
Although we might think of ourselves as rational, research shows that even the most minor of choices can be colored by our mood.
“Emotions have a profound effect on the process with which people make decisions,” says Lerner, who coauthored an article about emotion and decision-making in the 2015 Annual Review of Psychology. Especially when dealing with incidental emotions — a kind of background feeling unrelated to the decision at hand — we are often unaware of how it influences our thinking.
For example, Lerner and colleagues have found that anger — not uncommon when our lives are affected by a force outside our control — tends to lead to less thoughtful analysis. “Angry people don’t question themselves,” she says. “They don’t say, ‘Gosh, I wonder if I’m right about this. I’m not sure if I’m using the right information.’” And that can lead people to make less-than-ideal choices.
Perhaps even more prevalent than anger, these days, is sadness, as people lose not just loved ones or their own health but also income and freedom of movement. Unlike anger, though, “sadness actually makes you think more deeply” and can help to process information in a more robust, systematic way, Lerner says.
Lerner’s work has also shown that sadness can lead to poor financial decisions. “Sadness arising from loss triggers an implicit goal of replacing that loss,” she says. In experiments described in 2008 in Psychological Science, she and her colleagues found that study participants prompted into a sad mood were more willing to pay overly high prices to buy things immediately than those who were in a neutral mood. “So there’s a real risk, when you’re sad, of over-shopping and paying too much for things,” Lerner notes. This is especially troubling during a recession spurred by a loss-filled event like a global pandemic.
Fear has also been shown to be an influencer: Research done after 9/11 found that fear heightened people’s perception of risk, and so, too, their intentions to take precautions.
Searching for certainty
Another prevailing force right now is extreme uncertainty, which, as King puts it, “sucks.” This instability can lead people to seek narrow ranges of information in a quest for confirmation of their perspectives.
“One of the most important things that we all need to do is to become more comfortable with uncertainty. Relying on false certainty leads to a lot of bad decisions.”
Nicholas King
“Confirmation bias is a way of minimizing uncertainty: Because you’re only choosing evidence that confirms your preexisting world view, you can maintain a certain confidence level of what you already believe,” King says.
This, like anger, leads people to be less considerate of potentially wiser perspectives and options for behavior, such as weighing multiple sources of information about the safety of large gatherings like protests or religious services.
Adding to the trouble, this drive often perpetuates misguided certainty that can lead to similarly misguided behavioral choices. “In policy arenas and personal life — even in science — the person who declares things with certainty tends to garner more attention and a lot more trust than the person who expresses uncertainty,” King says.
Which, he says, gets things exactly backward.
“I trust the person who honestly and transparently discusses the uncertainties involved … much more,” King says. “One of the most important things that we all need to do is to become more comfortable with uncertainty. Relying on false certainty leads to a lot of bad decisions.”
Peer pressure
We rarely make decisions in a vacuum — even if they seem entirely personal. And we are influenced by those around us more than we might think.
A virus or rumor can transmit through simple contact. But for a more complex social behavior, like wearing a mask to protect others, the dynamics are much more complicated, explains Damon Centola, who studies social networks and social epidemiology at the Annenberg School for Communication at the University of Pennsylvania.
In this case, social networks act more like prisms, as Centola described in the 2019 Annual Review of Sociology. These networks actually “shape how we view the information we’re receiving, how responsive we are to the new behaviors we’re exposed to, and whether or not we accept them,” he says. “The idea is if people just have information, then they will make the rational choice. And that’s just wrong.”
As much as any recommendations from the CDC or the county health department, your peers affect the choices you make.
Centola gives the example of physical distancing early on in the pandemic. If you were the only one in your office to decide to not attend a meeting — or the only one of your friends to skip a dinner party — in an effort to physically distance, it might have had adverse professional or social effects. But if most of your colleagues (or friends) established the norm of not attending in-person gatherings, that decision becomes the default. The same might go for wearing masks in your neighborhood.
This lesson has takeaways for everyone up the decision-making chain. “This is a really important factor when we think about behavioral diffusion and really any public health policy that involves this kind of decision-making process,” Centola says.
When healthy is easy
To understand how to help people make better decisions in this pandemic, scientists are looking to insights gained from previous work on pro-social health behaviors. Gretchen Chapman, who studies social and decision sciences at Carnegie Mellon University, has done decades of research in this field, such as on people’s decisions to get vaccines.
“Trying to change people’s beliefs and feelings about vaccination is not very effective — it’s more effective to intervene on the behavior directly by making the behavior easy,” she says. (This can be as simple as automatically scheduling flu shot appointments.)
Any way to make the desired behavior decision as frictionless as possible is key, Chapman says. If you want people to decide to mostly avoid going to grocery stores, “grocery delivery should be really easy and accessible,” she says. Or if you’re trying to ensure mask wearing, have disposable masks available for people before they enter a store.
What also helps people make decisions about new behaviors is simply seeing massive change in their environment. As Chapman notes from her home in Pittsburgh, where springtime birds chirp in the background, “just looking around at my environment, I would never guess that this was a serious situation. But the governor closed public schools, and all the other universities have closed — I kind of sit up and take notice. I’m, like, ‘Oh, wow, I guess this must be a really big deal.’”
Centola has researched adoption of other highly visible pro-social behaviors, such as the decision to put solar panels on your house. Many government programs have tried information campaigns and financial incentives. But most effective were programs that installed panels on a certain number of houses per neighborhood, creating a contagion dynamic leading neighbors to follow the new norm.
What we can learn – and what we can do better
A better understanding of how we make decisions can not only help us make better ones, but it can also help experts learn how to nudge us toward healthy behaviors.
Chapman and colleagues, for example, are studying how different messages — straight informational versus one that includes an estimate of how popular something is (how many Americans are wearing masks, for example) — change people’s intended behavior, such as their plans to physically distance or wear a mask. She expects that whom the messaging depicts will also influence the results: “If they learn that other people like them in their neighborhood are wearing masks,” they may be more likely to plan to do the same, she says.
One grand challenge of public-health decision making is helping everyone make the best choices. As Centola says, where he lives in Philadelphia, a lot of people work jobs they cannot do from home. So there are large networks of people whose lives, by necessity, haven’t changed all that much.
“There’s a kind of equity issue built into a lot of the public-health campaigns,” he says. More affluent networks of people have the luxury of being able to shelter at home more or less full-time and act on high-level information, he notes. Whereas, “disadvantaged populations, even if they’re hearing that information, it’s just not as relevant to their circumstances, it’s not manageable. And so it gets ignored.” That can also be reinforced by social networks, Centola says. In this case, “inequities are reinforced by what they see their peers doing.”
One of the big challenges throughout the pandemic has, of course, been figuring out what the best decisions even are, given the unknowns about the Covid-19 virus. Good decisions may seem like moving targets as official recommendations keep changing, Chapman says. Which is all the more reason to be aware of not just the information we are getting, but also the actions we choose to take — or not.
\n
\n
\n
\n
10.1146/knowable-052620-1
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\n\n
\n
Katherine Harmon Courage is a freelance journalist, Scientific American contributor and author of the books Cultured and Octopus! You can follow her on Twitter for more pandemic — and octopus — coverage at @KHCourage or www.katherinecourage.com.
\n
\n
This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
$\"Knowable$ \n\n","field_tagline":"From mask wearing to physical distancing, individuals wield a lot of power in how the coronavirus outbreak plays out. Behavioral experts reveal what might be prompting people to act — or not.","field_xml_enabled":"1"},"relationships":{"field_ar_related_articles":{"data":[{"id":"1744","type":"paragraphs"},{"id":"1745","type":"paragraphs"}]},"field_banner":{"data":{"id":"1847","type":"images"}},"field_collections":{"data":[{"id":"explained","type":"collections"},{"id":"coronavirus-0","type":"collections"}]},"field_footer_articles":{"data":[{"id":"health-disease/2020/building-mouse-squad-against-covid-19","type":"articles"},{"id":"health-disease/2020/what-cytokine-storm","type":"articles"}]},"field_import_zip":{"data":{"id":"1848","type":"images"}},"field_tags":{"data":[{"id":"psychology","type":"tags"}]},"field_topic":{"data":{"id":"mind","type":"topics"}},"field_topics":{"data":[{"id":"society","type":"topics"},{"id":"mind","type":"topics"}]}}},{"id":"1917","type":"images","attributes":{"title":"psychopharmacology-1600x600.jpg","filename":"psychopharmacology-1600x600.jpg","uri":"public://articles/504/psychopharmacology-1600x600_1.jpg","styles":{"134_y":"https://www.knowablemagazine.org/sites/default/files/styles/134_y/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=HEch5oxi","1600_600":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=8cG1nndg","285_205":"https://www.knowablemagazine.org/sites/default/files/styles/285_205/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=sUbAaNgY","305_220":"https://www.knowablemagazine.org/sites/default/files/styles/305_220/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=Srx3Dr6j","400_y":"https://www.knowablemagazine.org/sites/default/files/styles/400_y/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=Pbi9rE52","500_288":"https://www.knowablemagazine.org/sites/default/files/styles/500_288/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=jZ1OWrV_","645_552":"https://www.knowablemagazine.org/sites/default/files/styles/645_552/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=T05Cljbl","750_y":"https://www.knowablemagazine.org/sites/default/files/styles/750_y/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=WJ6RUrAz","large":"https://www.knowablemagazine.org/sites/default/files/styles/large/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=sM6OH0-P","linkit_result_thumbnail":"https://www.knowablemagazine.org/sites/default/files/styles/linkit_result_thumbnail/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=hxSjI_X7","medium":"https://www.knowablemagazine.org/sites/default/files/styles/medium/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=GsPZN644","thumbnail":"https://www.knowablemagazine.org/sites/default/files/styles/thumbnail/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=PLaXVnR7"},"filemime":"image/jpeg","filesize":"324849","status":"1"}},{"id":"mind/2020/trouble-medicating-mental-illness","type":"articles","attributes":{"title":"The trouble with medicating mental illness","nid":"504","created":"1595003994","revision_default":"1","path":"590","body":"
\n $\"Artist’s$
\n\n
\n \n
CREDIT: JAMES PROVOST (CC BY-ND)
\n \n\n \n
Historian and psychiatrist Joel Braslow
\n \n\n \n
University of California, Los Angeles
\n \n
\n
The standard of care for the severely mentally ill in the United States has drastically changed since the 1950s, when more than half a million patients resided in enormous state hospitals. As pharmaceutical firms developed new antipsychotic medications, national policy shifted such that most of the old hospitals have now closed. Today, the majority of US patients, even those with serious mental illnesses such as schizophrenia, bipolar syndrome and major depression, receive only short-term, in-patient medical treatment to quell symptoms before being sent home.
The old asylums were the scenes of some well-publicized abuses and poor conditions. Yet their closures and the parallel embrace of medications did not solve the issue of how to best care for people. The current mental-health system leaves many mentally ill patients no better off, says Joel Braslow, a historian and psychiatrist at the University of California, Los Angeles. In some cases, the situation has grown worse.
In the 2019 Annual Review of Clinical Psychology, Braslow and UCLA colleague Stephen Marder argue that our current “age of psychopharmacology” has shrunk society’s sense of responsibility toward the mentally ill. Whereas most psychiatrists once viewed mental illness as a complex interaction between a patient’s biology and social context, Braslow and Marder contend, it is now often seen more narrowly as merely symptoms to be medicated.
Braslow blames this shift for what he calls our society’s “total failure” in caring for its most vulnerable members: Roughly 140,000 seriously mentally ill people are now homeless on city streets, while 350,000 others are serving time in prisons and jails, where their illnesses get little treatment.
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Knowable Magazine spoke with Braslow about the history of this transformation and what it would take to better serve the multitudes of people living with psychiatric problems.
This conversation has been edited for length and clarity.
Why do you call this the “age of psychopharmacology”?
I think about it in two different but interrelated ways. First, it underlines our growing reliance on drugs to treat disorders of the mind. Today, one in six Americans takes a psychoactive drug. This has reinforced the idea that the drugs treat specific diseases, much like insulin treats diabetes. For example, Tipper Gore (the ex-wife of former Vice President Al Gore) has explained her own depression as a chemical imbalance, with her brain running out of serotonin like a car runs out of gas. This description implies that depression has both a specific cause — in her case, depleted serotonin — and a specific cure, a drug.
Secondly, there’s our shrinking vision of what causes psychiatric disease and what we can do clinically for those who suffer from it. Prior to the late 1960s and 1970s, American psychiatrists tended to take a more expansive view. Today’s greater focus on the individual and a simple model of disease has helped justify the belief that drugs or psychotherapies hold the key to alleviating psychiatric disease. However, this view ignores the fundamental nature of psychiatric disease as simultaneously biological, psychological and social.
What accounts for this shift?
Psychoactive drugs have been used since the 19th century, but they were generally regarded as little more than sedatives — referred to as “chemical straitjackets.” The chance discovery of the major classes of psychotropic drugs in the 1950s changed the status of psychopharmacology. These new compounds did more than simply sedate; they actually treated many of the symptoms of psychiatric disease, such as hallucinations, depressed mood and disordered thoughts.
\n
\n $\"Ad$
\n\n
When the first effective psychotropic drugs came on the market, psychiatrists saw them as adjuncts to psychotherapy. For example, this ad from 1956 for the antipsychotic drug reserpine (Serpanray) says the drug “opens the door to more successful psychotherapy.”
\n \n \n
CREDIT: ADVERTISEMENT / AMERICAN JOURNAL OF PSYCHIATRY (FARRAR 1956)
\n \n \n
However — and this is a crucial point — throughout the 1950s and much of the 1960s, psychiatrists largely saw psychotropic drugs as just one part of an overall regimen, a part that neither dominated nor defined the nature of the disease and its treatment. Psychiatrists continued to see psychiatric disease in a holistic manner, in which symptoms could involve an individual’s failure to function in the social world and their inner torment. Treatment remained similarly expansive, especially when the illness warranted state hospitalization.
Things changed dramatically from the 1970s onward. It’s tempting to attribute this to the drugs’ effectiveness, but this is simply not the case. There has been little change in the actual efficacy of antidepressants, antipsychotics and anti-anxiety drugs over the last half-century. Social, economic and cultural circumstances did far more to bring on the age of psychopharmacology than did the effectiveness of the drugs themselves.
For one thing, psychiatric hospital administrators came under increasing pressure to decrease their hospitalized patient population. Hospital records from the 1970s show doctors under pressure to discharge patients earlier and earlier. So physicians, understandably, focused on symptoms that could be quickly and easily treated, and relied increasingly on drugs as their primary intervention. Under such circumstances, it became more and more impossible to address the thornier problems of how the patients functioned in the world.
\n
\n $\"Graphic$
\n\n
The number of patients in US mental institutions has declined precipitately since 1955. Many people with severe mental illness are now homeless or in prisons.
\n \n \n \n
You write that this change was also influenced by politics?
Yes. For nearly 150 years, state governments believed that society and physicians had a moral responsibility to provide care for all those afflicted with mental illness. But beginning in the late 1960s and 1970s, the welfare state came under increasing attack with the belief that individuals needed to take individual responsibility for themselves. State governments were primarily responsible for the smooth running of market economies and not for individual welfare. The elections of Ronald Reagan in the US and Margaret Thatcher in the UK underlined this shift in political culture.
These changes shifted care priorities away from state hospitals and toward care in the community. But that has become increasingly fragmented, decentralized and subject to the logic of market forces rather than to the needs of those with serious mental illness.
The political ideology that emphasizes individual responsibility fits neatly with a belief that disease is largely a problem of biology and/or psychology and that the solution is a treatment that focuses on the individual’s psychology or biology.
Given that we’re relying more on medications, how well do they actually work?
That’s a difficult question to answer. Take schizophrenia, for example. We don’t have a good understanding of the causes of what are likely multiple different kinds of schizophrenia, but there’s a growing belief that antipsychotic drugs can do little for the fundamental symptoms of apathy, social withdrawal and cognitive deficits. These drugs do, however, treat other symptoms — hearing voices, speaking incoherently and behaving in an agitated way.
We have good evidence that antipsychotic drugs help prevent relapse in the short run, although the jury is still out whether someone should be on antipsychotic drugs for a lifetime. So, yes, they work, but only with a number of important caveats. I think the same could also be said for antidepressant drugs.
\n
\n \n
\n\n \n\n
You write that the medical system’s increasing reliance on randomized controlled trials helped fuel the shift toward drugs. Is the problem that it’s somehow easier to test medications than psychotherapies?
The short answer to that is yes.
A randomized controlled trial requires easily measurable variables and, consequently, has shifted our understanding towards an increasingly reductionistic view of psychiatric disease that excludes many of the social and psychological realities. It encourages us to think in terms of specific interventions, such as psychotropic drugs, that treat a specific, discrete disease, just like antibiotics treat bacterial infections. This way of thinking fails to accommodate the complex social and psychological deficits intrinsic to psychiatric disease.
How have the patients fared with these changes?
Despite good intentions, advances in neuroscience and an increasingly large number of psychotropic drugs, those afflicted with serious mental illness have not done well. Overall, outcomes such as mortality and social function have worsened for the vast majority with serious mental illness. You can see it in the unprecedented population of mentally ill homeless people — 60,000 just in Los Angeles. We’re allowing people who are disabled by psychosis to languish in the streets. This wouldn’t happen with cardiac patients.
And a lot of those homeless people end up in jail.
True. Today there are about 5,000 seriously mentally ill people in the Los Angeles County jail. I have a hard time going to the jail myself — it’s such a horrible place. Many of the sickest patients refuse medications, often exacerbating their psychotic symptoms. The sheriff has little recourse but to house the most psychotic, non-compliant inmates in isolation, so as to be the least disruptive to the other inmates and guards.
About a thousand inmates are in solitary confinement, in individual Plexiglas cells for 23 hours a day. At the same time, these terribly psychotic individuals are left to disrobe, smear feces and a variety of other psychotic symptoms that worsen under conditions of isolation and deprivation. Any time they’re out of their cells, they are almost invariably shackled, even while seeing a psychiatrist. It’s heartbreakingly sad.
So how should society respond? Do we need to go back to the asylums of the past?
I think we need to learn from the positive aspects of asylum care. Rather than either reestablishing the asylums or intensifying the alienation and neglect of the last 50 years, we need to come up with new, evidence-based ways of caring for those with serious mental illness.
Once we acknowledge the reality of mental illness as a disease that robs its victims of meaning, social connections and the ability to function in contemporary society, we can start designing interventions that address this reality. We cannot simply wish away the complexity of psychiatric disease and the kinds of interventions that are necessary for humane, scientifically based care.
\n","field_all_authors":"
\n \n \n \n By\n\n \n Katherine Ellison\n \n \n \n \n 07.17.2020\n
\n","field_ar_article":{"arguments":[]},"field_author_bios":"
\n
Katherine Ellison is a journalist and author based in the San Francisco Bay Area.
\n
\n","field_banner_alt":"Patients in a mental hospital square-dancing.","field_banner_title":"Square-dancing patients","field_caption":"
Patients at Worcester State Hospital, a mental institution in Massachusetts, square-dancing in the 1940s. For all their well-documented abuses, many of the old state hospitals also provided a supportive environment for people unable to function on their own in society.
\n","field_credit":"
CREDIT: PHOTO BY HERBERT GEHR / THE LIFE PICTURE COLLECTION VIA GETTY IMAGES
","field_doi":"10.1146/knowable-071620-3","field_headline":"Q&A — Psychiatrist and historian Joel Braslow","field_headline_url":{"arguments":["collection","qa"],"type":"client"},"field_is_hero":"1","metatags":{"referrer":"origin","title":"The trouble with medicating mental illness","description":"Psychotropic drugs have severely narrowed how we treat psychiatric disorders — to the detriment of patients and society as a whole. A look at the past suggests a better way forward.","google_plus_name":"The trouble with medicating mental illness","og_title":"The trouble with medicating mental illness","og_site_name":"Knowable Magazine | Annual Reviews","og_type":"article","twitter_cards_type":"summary_large_image","canonical_url":"/article/mind/2020/trouble-medicating-mental-illness","dcterms_description":"Psychotropic drugs have severely narrowed how we treat psychiatric disorders — to the detriment of patients and society as a whole. A look at the past suggests a better way forward.","dcterms_identifier":"10.1146/knowable-071620-3","dcterms_publisher":"Annual Reviews","dcterms_title":"The trouble with medicating mental illness","dcterms_type":"article","fb_admins":"1642929092406128","google_plus_description":"Psychotropic drugs have severely narrowed how we treat psychiatric disorders — to the detriment of patients and society as a whole. A look at the past suggests a better way forward.","google_plus_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=8cG1nndg","citation_author":"","citation_journal_title":"Knowable Magazine | Annual Reviews","citation_publication_date":"Friday, July 17, 2020 - 08:00","citation_title":"The trouble with medicating mental illness","article_modified_time":"Tuesday, July 28, 2020 - 12:49","article_published_time":"Friday, July 17, 2020 - 08:00","og_description":"Psychotropic drugs have severely narrowed how we treat psychiatric disorders — to the detriment of patients and society as a whole. A look at the past suggests a better way forward.","og_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=8cG1nndg","og_image_height":"600","og_image_type":"image/jpeg","og_image_url":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=8cG1nndg","og_image_width":"1600","og_updated_time":"Tuesday, July 28, 2020 - 12:49","og_url":"/article/mind/2020/trouble-medicating-mental-illness","twitter_cards_description":"Psychotropic drugs have severely narrowed how we treat psychiatric disorders — to the detriment of patients and society as a whole. A look at the past suggests a better way forward.","twitter_cards_image":"https://www.knowablemagazine.org/sites/default/files/styles/1600_600/public/articles/504/psychopharmacology-1600x600_1.jpg?itok=8cG1nndg","twitter_cards_image_height":"600","twitter_cards_image_width":"1600","twitter_cards_page_url":"/article/mind/2020/trouble-medicating-mental-illness","twitter_cards_site":"@knowablemag","twitter_cards_title":"The trouble with medicating mental illness","dc_identifier":"10.1146/knowable-071620-3","pocket-site-verification":"665d7e2e5dc1fa27727a154d5c4e80"},"field_primary_author":"By Katherine Ellison","field_published":"2020-07-17","field_republish_html":"
Q&A — Psychiatrist and historian Joel Braslow
\n
The trouble with medicating mental illness
\n
Psychotropic drugs have severely narrowed how we treat psychiatric disorders — to the detriment of patients and society as a whole. A look at the past suggests a better way forward.
\n
\n By Katherine Ellison \n \n
\n
7.17.2020
\n
The standard of care for the severely mentally ill in the United States has drastically changed since the 1950s, when more than half a million patients resided in enormous state hospitals. As pharmaceutical firms developed new antipsychotic medications, national policy shifted such that most of the old hospitals have now closed. Today, the majority of US patients, even those with serious mental illnesses such as schizophrenia, bipolar syndrome and major depression, receive only short-term, in-patient medical treatment to quell symptoms before being sent home.
The old asylums were the scenes of some well-publicized abuses and poor conditions. Yet their closures and the parallel embrace of medications did not solve the issue of how to best care for people. The current mental-health system leaves many mentally ill patients no better off, says Joel Braslow, a historian and psychiatrist at the University of California, Los Angeles. In some cases, the situation has grown worse.
In the 2019Annual Review of Clinical Psychology, Braslow and UCLA colleague Stephen Marder argue that our current “age of psychopharmacology” has shrunk society’s sense of responsibility toward the mentally ill. Whereas most psychiatrists once viewed mental illness as a complex interaction between a patient’s biology and social context, Braslow and Marder contend, it is now often seen more narrowly as merely symptoms to be medicated.
Braslow blames this shift for what he calls our society’s “total failure” in caring for its most vulnerable members: Roughly 140,000 seriously mentally ill people are now homeless on city streets, while 350,000 others are serving time in prisons and jails, where their illnesses get little treatment.
Knowable Magazine spoke with Braslow about the history of this transformation and what it would take to better serve the multitudes of people living with psychiatric problems.
This conversation has been edited for length and clarity.
Why do you call this the “age of psychopharmacology”?
I think about it in two different but interrelated ways. First, it underlines our growing reliance on drugs to treat disorders of the mind. Today, one in six Americans takes a psychoactive drug. This has reinforced the idea that the drugs treat specific diseases, much like insulin treats diabetes. For example, Tipper Gore (the ex-wife of former Vice President Al Gore) has explained her own depression as a chemical imbalance, with her brain running out of serotonin like a car runs out of gas. This description implies that depression has both a specific cause — in her case, depleted serotonin — and a specific cure, a drug.
Secondly, there’s our shrinking vision of what causes psychiatric disease and what we can do clinically for those who suffer from it. Prior to the late 1960s and 1970s, American psychiatrists tended to take a more expansive view. Today’s greater focus on the individual and a simple model of disease has helped justify the belief that drugs or psychotherapies hold the key to alleviating psychiatric disease. However, this view ignores the fundamental nature of psychiatric disease as simultaneously biological, psychological and social.
What accounts for this shift?
Psychoactive drugs have been used since the 19th century, but they were generally regarded as little more than sedatives — referred to as “chemical straitjackets.” The chance discovery of the major classes of psychotropic drugs in the 1950s changed the status of psychopharmacology. These new compounds did more than simply sedate; they actually treated many of the symptoms of psychiatric disease, such as hallucinations, depressed mood and disordered thoughts.
However — and this is a crucial point — throughout the 1950s and much of the 1960s, psychiatrists largely saw psychotropic drugs as just one part of an overall regimen, a part that neither dominated nor defined the nature of the disease and its treatment. Psychiatrists continued to see psychiatric disease in a holistic manner, in which symptoms could involve an individual’s failure to function in the social world and their inner torment. Treatment remained similarly expansive, especially when the illness warranted state hospitalization.
Things changed dramatically from the 1970s onward. It’s tempting to attribute this to the drugs’ effectiveness, but this is simply not the case. There has been little change in the actual efficacy of antidepressants, antipsychotics and anti-anxiety drugs over the last half-century. Social, economic and cultural circumstances did far more to bring on the age of psychopharmacology than did the effectiveness of the drugs themselves.
For one thing, psychiatric hospital administrators came under increasing pressure to decrease their hospitalized patient population. Hospital records from the 1970s show doctors under pressure to discharge patients earlier and earlier. So physicians, understandably, focused on symptoms that could be quickly and easily treated, and relied increasingly on drugs as their primary intervention. Under such circumstances, it became more and more impossible to address the thornier problems of how the patients functioned in the world.
You write that this change was also influenced by politics?
Yes. For nearly 150 years, state governments believed that society and physicians had a moral responsibility to provide care for all those afflicted with mental illness. But beginning in the late 1960s and 1970s, the welfare state came under increasing attack with the belief that individuals needed to take individual responsibility for themselves. State governments were primarily responsible for the smooth running of market economies and not for individual welfare. The elections of Ronald Reagan in the US and Margaret Thatcher in the UK underlined this shift in political culture.
These changes shifted care priorities away from state hospitals and toward care in the community. But that has become increasingly fragmented, decentralized and subject to the logic of market forces rather than to the needs of those with serious mental illness.
The political ideology that emphasizes individual responsibility fits neatly with a belief that disease is largely a problem of biology and/or psychology and that the solution is a treatment that focuses on the individual’s psychology or biology.
Given that we’re relying more on medications, how well do they actually work?
That’s a difficult question to answer. Take schizophrenia, for example. We don’t have a good understanding of the causes of what are likely multiple different kinds of schizophrenia, but there’s a growing belief that antipsychotic drugs can do little for the fundamental symptoms of apathy, social withdrawal and cognitive deficits. These drugs do, however, treat other symptoms — hearing voices, speaking incoherently and behaving in an agitated way.
We have good evidence that antipsychotic drugs help prevent relapse in the short run, although the jury is still out whether someone should be on antipsychotic drugs for a lifetime. So, yes, they work, but only with a number of important caveats. I think the same could also be said for antidepressant drugs.
You write that the medical system’s increasing reliance on randomized controlled trials helped fuel the shift toward drugs. Is the problem that it’s somehow easier to test medications than psychotherapies?
The short answer to that is yes.
A randomized controlled trial requires easily measurable variables and, consequently, has shifted our understanding towards an increasingly reductionistic view of psychiatric disease that excludes many of the social and psychological realities. It encourages us to think in terms of specific interventions, such as psychotropic drugs, that treat a specific, discrete disease, just like antibiotics treat bacterial infections. This way of thinking fails to accommodate the complex social and psychological deficits intrinsic to psychiatric disease.
How have the patients fared with these changes?
Despite good intentions, advances in neuroscience and an increasingly large number of psychotropic drugs, those afflicted with serious mental illness have not done well. Overall, outcomes such as mortality and social function have worsened for the vast majority with serious mental illness. You can see it in the unprecedented population of mentally ill homeless people — 60,000 just in Los Angeles. We’re allowing people who are disabled by psychosis to languish in the streets. This wouldn’t happen with cardiac patients.
And a lot of those homeless people end up in jail.
True. Today there are about 5,000 seriously mentally ill people in the Los Angeles County jail. I have a hard time going to the jail myself — it’s such a horrible place. Many of the sickest patients refuse medications, often exacerbating their psychotic symptoms. The sheriff has little recourse but to house the most psychotic, non-compliant inmates in isolation, so as to be the least disruptive to the other inmates and guards.
About a thousand inmates are in solitary confinement, in individual Plexiglas cells for 23 hours a day. At the same time, these terribly psychotic individuals are left to disrobe, smear feces and a variety of other psychotic symptoms that worsen under conditions of isolation and deprivation. Any time they’re out of their cells, they are almost invariably shackled, even while seeing a psychiatrist. It’s heartbreakingly sad.
So how should society respond? Do we need to go back to the asylums of the past?
I think we need to learn from the positive aspects of asylum care. Rather than either reestablishing the asylums or intensifying the alienation and neglect of the last 50 years, we need to come up with new, evidence-based ways of caring for those with serious mental illness.
Once we acknowledge the reality of mental illness as a disease that robs its victims of meaning, social connections and the ability to function in contemporary society, we can start designing interventions that address this reality. We cannot simply wish away the complexity of psychiatric disease and the kinds of interventions that are necessary for humane, scientifically based care.
\n
\n
\n
\n
10.1146/knowable-071620-3
\n
\n\n
\n
Katherine Ellison is a journalist and author based in the San Francisco Bay Area.
\n
\n
This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.
$\"Knowable$ \n\n","field_tagline":"Psychotropic drugs have severely narrowed how we treat psychiatric disorders — to the detriment of patients and society as a whole. A look at the past suggests a better way forward.","field_xml_enabled":"1"},"relationships":{"field_ar_related_articles":{"data":[{"id":"1800","type":"paragraphs"},{"id":"1801","type":"paragraphs"}]},"field_banner":{"data":{"id":"1917","type":"images"}},"field_collections":{"data":[{"id":"qa","type":"collections"}]},"field_footer_articles":{"data":[{"id":"mind/2020/adhd-in-girls-and-women","type":"articles"},{"id":"technology/2020/information-apocalypse-the-problem-with-deepfakes","type":"articles"}]},"field_import_zip":{"data":{"id":"1918","type":"images"}},"field_topic":{"data":{"id":"mind","type":"topics"}},"field_topics":{"data":[{"id":"health-disease","type":"topics"},{"id":"society","type":"topics"},{"id":"mind","type":"topics"}]}}},{"id":"mind","type":"topics","attributes":{"title":"The Mind","bundle":"topics","field_nof":3,"tid":"17","description":"","weight":"6","path":"29","metatags":{"referrer":"origin","title":"The Mind | Knowable Magazine | Annual Reviews","description":"","pocket-site-verification":"665d7e2e5dc1fa27727a154d5c4e80"},"field_pattern":"pattern-mind","field_promote":"1"},"relationships":{"field_featured_articles":{"data":[{"id":"mind/2020/how-to-curb-implicit-bias","type":"articles"},{"id":"mind/2020/how-we-make-decisions-during-pandemic","type":"articles"},{"id":"mind/2020/trouble-medicating-mental-illness","type":"articles"}]}}},{"id":"4","type":"donation_promos","attributes":{"title":"Home Banner Promo","id":"4","revision_created":"1555341423","created":"1555341423","revision_default":"1","field_button":{"arguments":["page","support-knowable-magazine"],"title":"Donate","type":"pages"},"field_enabled":"1","field_promo_title":"Support Knowable Magazine","field_promo_type":"home_banner","field_text":"
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