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Astronomy

- Meet the Asteroids Next Door

ASTRONOMY | VIEW ON WEBSITE

Meet the Asteroids Next Door

A radar system is set to map near-Earth objects as they fly by

By Katherine Harmon Courage    September 9, 2025

Rocketing by at tens of thousands of miles per hour, the asteroids visiting Earth’s neighborhood will get a closeup this week. Using radar, scientists will be scanning these space rocks as they whiz by our planet, creating newly detailed profiles of the near-Earth objects for further study.

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The technology, deployed by NASA’s Deep Space Network Goldstone Solar System Radar, recently captured alluring new profiles of asteroid “1997 QK1,” which sailed by Earth last month in its closest approach in more than three and a half centuries. The “peanut”-shaped rock is about 600 feet across, and the more-than two dozen new radar images relayed novel information about its form and spin.

The radar system can reveal details about space rocks at a resolution of some 25 feet—not too bad for targets zipping by at such high speeds, often more than a million miles away. The resulting images can tell us a lot about these celestial near-Earth objects, including more information about their size and rotation, as well as their density.

Many of the objects the radars scan are almost complete unknowns to science. For example, this week, the asteroids the Goldstone radar will be profiling include an object known as “2025 QO1,” which was just discovered this August. It might be about 250 feet across, “but otherwise, nothing is known about its physical properties,” NASA reports.

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MILLION-MILE CLOSE-UP: Scientists are using old tech to get new looks at passing asteroids. This new series of images, taken in late August, reveal never-before-seen details of a “peanut”-shaped asteroid as it flew by Earth. The radar system has a full calendar of other near-Earth objects to scan. Credit: NASA/JPL-Caltech.

Another object up for radar imaging is the 100-plus foot “2025 QV9,” discerned from data collected by the Pan-STARRS 1 telescope in Hawaii just a couple of weeks ago. This might not sound like too hefty of an object, as far as the cosmos go, but, as astrophysicist Paul Sutter explained for Nautilus, as recently as 50,000 years ago, a 150-foot wide asteroid collided with what is now Arizona, unleashing the energy “equivalent to 600 Hiroshima bombs … [and] a 1,000-mph wind blast more than two miles from the site.”

Finally, there is “2009 FF,” which was first documented in 2009 by the massive Mount Lemmon Survey in Arizona, an ongoing project that has been particularly successful in locating near-Earth objects. This week’s visit from 2009 FF, which seems to be about 500 feet across, will be the closest it comes to Earth for the next 149 years.

But even the closest of these, 2025 QV9 will still be at a reasonably comfortable distance from Earth, of about 1.2 million miles.

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Later this month, the Goldstone radar system will also get a chance to scan “2025 FA22,” spotted earlier this year from the Pan-STARRS project in Hawaii and which was previously flagged as a potential impact object. That designation has been downgraded, but at close to 500 feet wide, it is the largest asteroid to get this close (within about half a million miles) to Earth since 2022, and it will likely maintain this designation until 2027. Like so many other near-Earth objects, “little is known about its physical properties,” as NASA notes. The upcoming radar imaging will likely reveal more about this close visitor.

You can see a list of the upcoming objects the radar system will be scanning here. And if you want a more in-depth picture of the hunt for potentially Earth-intersecting rocks from space, we have a story for you about the people leading this wild effort.

Lead image: Triff / Shutterstock

Katherine Harmon Courage

Posted on September 9, 2025

Katherine Harmon Courage is the executive editor at Nautilus.

Communication

- Scientists Are People, Too

COMMUNICATION | VIEW ON WEBSITE

Scientists Are People, Too

Can humanizing scientists help win back public trust?

By Nick Hilden    September 11, 2025

It’s no secret that we’re in an era of endemic skepticism toward science. You see it in the news every day. Figures at the apex of government disregarding decades of well-established medical evidence. The defunding of university research programs and dismantling of medical infrastructure. Scientific experts replaced in agency leadership posts by the discredited and the woo. Suffice it to say that, regardless of its manifold benefits we enjoy every day, science is on its heels.

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There are many reasons for this, but according to Alan Lightman and Martin Rees, much of the problem comes down to the fact that the general public simply doesn’t have a good understanding of what science is and what scientists do. With their new book The Shape of Wonder: How Scientists Think, Work, and Live, they aim to correct this by exploring the scientific life, from the real inspirations and experiences of wide-ranging scientists, to how the scientific method is practiced, to how science is leveraged in our culture and institutions.

Scientists have the same emotions, jealousies, ambitions, and passions as other people.

The author duo is more than equipped to provide such insight. Lightman has held prominent science faculty positions at Harvard and MIT and serves on the United Nations Secretary-General’s Scientific Advisory Board. Rees is the recipient of the prestigious Wolf Prize in Physics, served as Master of Trinity College in Cambridge, and spent 30 years as the United Kingdom’s Astronomer Royal. And both have hobbies, struggles, aspirations, and fears just like anyone else. They are scientists with specialized knowledge, but also humans with everyday impulses.

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“Scientists are people,” Lightman told Nautilus. “They are concerned about their society like the rest of us.” Many of those unfamiliar with science, however, have become mistrusting of its practitioners’ motivations. As Lightman explains below, the solution will involve greater transparency between scientists and the public, hopefully propagating an appreciation of the value science can offer for the good of all.

Throughout the book, you dive into a lot of different scientists’ individual stories. Were you struck by any one in particular?

We profile a number of scientists in the book—some well-known, some people you’ve never heard of—to help humanize scientists. I was most impressed by the neuroscientist Lace Riggs, who works at MIT’s McGovern Center for Brain Science. She grew up in a very rough neighborhood in Southern California. Her family was swept up by drug addiction, mental illness, and suicide. Her father left early, her mother struggled, and they moved from one apartment to the next when they couldn’t pay rent. Yet somehow she got to community college, then went all the way to a Ph.D. in neuroscience, and is now a postdoctoral fellow at MIT doing original research on drugs that will help people with mental disabilities and addictions. I’m impressed by her story because she was motivated by something that happened in her childhood, but also because she overcame incredible obstacles to get a Ph.D. in science and become a researcher at a leading institution, starting off in the worst conditions imaginable. That really says a lot about the human spirit.

What do you think the general public most misunderstands about what it means to be a scientist?

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Understanding that scientists are human beings—that we have the same emotions, jealousies, ambitions, and passions as other people. Scientists are often set aside as being different. Scientists have specialized knowledge, and everybody recognizes that science and technology are very important factors in driving our world today. The fact that this certain group of people have specialized knowledge makes others worried and suspicious, skeptical, uneasy. But I think that if people—meaning a certain fraction of the country—understood that most scientists are working for the good of society, that might eliminate some of the skepticism.

You wrote how science used to be part of the American identity. How has that changed over the years?

In the 19th century, there were a number of scientific projects led by the National Geological Survey; the telegraph, railroads, and a number of other big projects associated with a young country exploring and improving. Science and technology were really part of the growth of the United States, and became part of our self-identity as a country of entrepreneurs, risk takers, adventurers. Until very recent years, that was part of our national identity. Google and Apple and the laptop computer, the transistor—all of that came out of the United States.

But if we start making the U.S. an unpleasant place for entrepreneurs to work, then all of that talent is going to leave our country. And it already has started. There are some scientists, technologists, and engineers who have left the United States because it’s no longer a wholesome and welcome environment to work in. I’m not so concerned with our competitive position relative to other countries. I don’t think that we have to be the best at everything. But I do think that our own standard of living and quality of life is going to diminish if we lose our talented scientists and technologists, including in the medical field.

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The book lists several key scientific challenges looming over the present and near future. Which of these do you think are the most pressing?

Artificial intelligence. It’s developing so rapidly that even leaders in the field don’t know when certain benchmarks are going to occur. It’s changing everything in ways we can’t possibly imagine. Not only the workforce, but new drugs are being discovered much more rapidly because a computer can test lots of different configurations of molecules very quickly. We’re going to have androids around the house pretty soon, some of them might look like human beings. We’re going to have computer chips that connect our brains directly to the internet. We already have the capacity to implant electrodes in people’s brains so that they can move a robot arm by pure thought. That technology is already 10 years old. So I would say artificial intelligence is changing our world more dramatically and swiftly than anything else.

After that, I would put neuroscience. There’s a lot of new research being done about the brain and the interface between the brain and the computer. I think it’s side-by-side with artificial intelligence. We’re learning more and more about how to modify the brain as well. All of this is really changing who we are as human beings. We’re evolving to something you might call Homo-techno: part human, part machine. It’s changing our conception of who we are as individuals and as a species. It’s almost impossible to imagine what it will be like in just 100 years from now.

Science and technology were once part of our self-identity as a country of entrepreneurs, risk takers, adventurers.

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You write that many of the challenges we face involve time scales of many decades. Why is it important for the public to understand that?

It’s important to understand that they’re much longer than the period of four years of a political figure. Most politicians are concerned, and naturally so, about being re-elected. They’re worried about the immediate future. An environmental issue that’s not going to happen for 15 years is not really of much concern to them in terms of their professional life. It may be a personal concern, but it’s not something they want to invest in. They’re going to invest in what it takes to get re-elected. And so the time horizons of our political leaders are relatively short compared to the time horizons of, for example, climate change. Artificial intelligence is developing so rapidly that it is within the time frame of an elected official, and I think some are concerned with that. But there are developments in neuroscience, for example, that have longer timescales, and climate science for sure. The public needs to understand that we need to think about these things happening on longer timescales, even if our politicians are not. Politicians are ultimately subject to the vote of the electorate, so if the electorate understands these things, maybe we can get the politicians to understand as well.

Prior to the scientific method, statements about the physical world were assessed based on the authority of the speaker, as you note in the book. Lately it seems like we’re reverting back to that, at least on a political level. Does that sound accurate?

I would absolutely agree with that, yes. And we don’t have to name names, we know who we’re talking about. You don’t need to know anything else, just listen to my voice. Well, that’s going to lead to a lot of trouble. Because once we start departing from evidence-based thinking we will be going on assumptions that are not validated by experiment. Climate change, depleting natural resources of our environment—we need bona fide scientists working on those problems who understand them. We need chemists and physicists and climatologists working on those problems. Without them, we’re gonna go back to the dark ages. We’re really going backwards now in so many areas, but the mistrust of scientists is one of the areas that can have a domino effect.

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How does science win back the public trust?

By showing that most scientists are working for the benefit of their societies. I’m a member of a small U.N. committee advising the Secretary-General on how to restore trust in science. We’re instituting local community forums in different countries, addressing local problems like polluted drinking water or grazing disputes, and showing how science helps solve those problems. That shows on a very local, community level how scientists work for the benefit of society. We need a lot more of that kind of thing.

Some people assert that scientists get into the field for big grant money. Where did they get this impression?

It’s part of the politicization of many aspects of science. I don’t know why particular scientists are thought to work just for the money, but I’ve interviewed many scientists, and I think I probably know a lot more scientists than the people who make those claims. I’ve lived in the scientific community myself, and I know the vast majority of scientists are working either for the benefit of society or for pure intellectual curiosity, but not for money and not for power. Money and commercial interests have gotten very mixed up with our politics for a number of years, so I think it’s natural that some people who are skeptical of scientists would blame it on their being pawns of financial or political interest.

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What roles do skepticism and competition play in science?

Most scientists I’ve known are competitive, and that’s a good thing because it gets people to do their best. Scientists critique each other’s work. The scientific method, in which we revise our theories when they disagree with experiment, arises from the community of scientists. Individual scientists can become emotionally involved and cling to pet theories even after they’re disproved, but inside the community we are very hard on each other. If someone claims a result and wants to win a Nobel Prize, I’m going to try to reproduce that experiment and prove them wrong. That’s the spirit of science.

Lead image: Wikimedia Commons

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Nick Hilden

Posted on September 11, 2025

Arts, science, and travel writer Nick Hilden contributes to the likes of the Washington Post, Scientific American, Esquire, Popular Science, National Geographic, and more. You can follow him on Twitter at @nickhilden or Instagram at @nick.hilden.

Environment

- Rogue Wave Mystery Solved

- You Can Help NASA Track Hurricane Damage

- This Forest Survived a Megafire

- Cities Obey the Laws of Living Things

ENVIRONMENT | VIEW ON WEBSITE

Rogue Wave Mystery Solved

Each leviathan of the deep has a signature that can be used to forecast it

By Kristen French    September 10, 2025

On New Year’s Day in 1995, an 80-foot wall of water hammered into a gas platform off the coast of Norway in the North Sea. As with most rogue waves, it rolled through the open ocean unaccompanied and under the radar. It was a singular monster. No other waves of its size followed, and no warning preceded its impressive crest. Named the Draupner wave after the gas platform it struck, it became the first scientifically confirmed rogue wave in history, corroborating hundreds of years of maritime lore.

“It confirmed what seafarers had described for centuries,” said Francesco Fedele, an engineering professor at Georgia, in a statement.  “For a long time, we thought this was just a myth.”

In the intervening decades, the Draupner wave and other rogues became the subject of much speculation and scientific analysis. No one really understood what mysterious forces drove such exotic leviathans of the deep to form. Rogue waves often appear during severe storms. But the data scientists collected about them did not present any clear answers about their origins, making them difficult to forecast and dangerous for ships and their crews, many of which have been lost to rogue wave strikes.

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Rogue waves are part of the ocean’s language.

Scientists have generally assumed extraordinary forces must drive such extraordinary waves, and have gone to great lengths to identify these forces. But Fedele and a team of researchers studied 18 years of data from the North Sea and discovered that, in fact, two natural ocean wave processes conspire to generate rogue waves. First, several large waves line up and amplify each other. Second, natural wave effects stretch the shape in a nonlinear way, increasing the size by an additional 15 to 20 percent. Together, these two processes can produce a single massive mountain of water.

According to Fedele, rogue waves result from natural ocean dynamics—they are not exceptions to them. “This is the most definitive, real-world evidence to date,” added Fedele, who has long been skeptical of traditional explanations for rogue waves. The dominant theory until now had attributed them to so-called “modulational instability”—small and unusual changes in the spacing and timing of waves. The team reported their findings in Scientific Reports.

The data the scientists collected included 27,500 wave records, which consisted of 30 minutes of recordings of height, frequency, and direction per wave, the most comprehensive dataset of its kind. Each rogue wave carries a kind of fingerprint, said Fedele. The dynamics of the ocean waves that precede and follow the peak can reveal how it formed. He is now using machine learning to comb through decades of data to help perfect forecasting models to protect ships and crews from future rogue wave disasters.

“Rogue waves are, simply, a bad day at sea,” Fedele said. “They are extreme events, but they’re part of the ocean’s language. We’re just finally learning how to listen.”

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Lead image: RugliG / Shutterstock

Kristen French

Posted on September 10, 2025

Kristen French is an associate editor at Nautilus.

ENVIRONMENT | VIEW ON WEBSITE

You Can Help NASA Track Hurricane Damage

Cell phone photos can help in recovery efforts

By Molly Glick    September 8, 2025

You likely have just the tool you need to keep your community whole in the wake of a hurricane—in your pocket. With just a smartphone, you can snap photos in your area to provide crucial data to scientists and disaster response teams, helping them react more quickly and effectively when these natural disasters strike.

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While these experts rely on technologies like weather radar and satellite imagery, they tend to lack detailed information from people on the ground. That’s why NASA, in collaboration with GLOBE, an international community science program, invites us to join its Response Mappers team, an initiative aiming to pinpoint shifts in land cover before and after hurricanes through crowdsourced data. You can get involved by downloading the GLOBE Observer app and joining the NASA Response Mappers team.

By regularly documenting the same spots in your neighborhood, anywhere from once a week to once a month, hurricane response experts get a much-needed close-up look at the typical conditions—from your local flora to high-rises. While the project kicked off earlier this summer, NASA is seeking data through October 31, near the end of the Atlantic hurricane season.

The project is centered around the southeastern United States, where hurricanes tend to land, but anyone is welcome to submit their snaps to boost future recovery and research efforts. This work is especially urgent as climate change raises the chances of quickly intensifying storms, and sea level rise worsens storm surge flooding.

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“Citizen science gives us ground truth,” said Joshua Barnes, manager for NASA’s Disasters Response Coordination System, in a statement. “The more eyes on the ground, the better we can serve communities in need.”

In the aftermath of a storm, your images can alert emergency responders to areas that require cleanup—but NASA emphasizes that Response Mappers participants should only venture out in safe conditions. This information is added to an open data set that can be wielded to verify satellite images, gauge the extent of damage, and inform future research, such as studies on how healthy wetlands can ease the impacts of floods. GLOBE and NASA are also working to help participants track their data’s journey by creating observation maps.

“At the end of the season, we hope to tell a story that begins with everyday people helping NASA deliver life-saving insights,” Barnes said. “And it can all start with a photo.”

Learn more about the project here.

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Lead image: Bilanol / Shutterstock

Molly Glick

Posted on September 8, 2025

Molly Glick is the newsletter editor of Nautilus.

ENVIRONMENT | VIEW ON WEBSITE

This Forest Survived a Megafire

Saving it involved destroying it twice

By Mark Degraff    September 8, 2025

Five miles down a bumpy dirt road in Plumas National Forest, at the northern end of the Sierra Nevada mountain range, lies a paradox. On one side of the road, a scorched wasteland of burnt toothpicks covers the Earth, a stark reminder of the devastating Dixie Fire that swept through this area four years ago. Not a single living tree remains. But a few hundred feet away, a stand of hardy, healthy ponderosa pines shoot into the sky, their branches reaching toward the sun. Small burn marks on the trunks of these trees are the only evidence of that brutal fire, which devoured nearly 1 million acres across five counties in 2021, making it California’s largest single wildfire to date.

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How did one stand manage to survive such a devastating blaze almost intact when the other perished entirely? As bigger and hotter fires increasingly wipe out entire forests in California, leading to unprecedented loss of huge swaths of woodland, forest managers understandably want an answer to this question, backed by hard evidence.

That’s why, late last year, a team of researchers from California, the Forest Service, and The Nature Conservancy took a systematic look at how different forest management practices influence the frequency of fires that kill entire groves of trees. They surveyed 164 study plots that burned in the Dixie Fire, including the two neighboring stands in Plumas National Forest. It turns out that between 2003 and 2005, the U.S. Forest Service had removed roughly two‑thirds of the trees in the surviving stand, and set a prescribed burn. The forest that went up in flames had been left untouched.

The odds that the megafire killed all the trees on the plot sank to just 4 percent.

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The most commonly used methods to protect forests against megafires today include either thinning the trees or setting prescribed burns, and sometimes both. But some have begun to question whether controlled burns are effective during increasingly intense droughts, given the risks that such burns could spiral out of control. And while plenty of research has looked at how thinning and burns influence fire severity, few efforts have studied how these treatments affect the longer-term survival of individual groves of trees.

When the researchers analyzed the data from their plots, what they found is that thinning trees alone is not much better than a total lack of forest management. This is possibly due to the fact that some methods of tree thinning actually can increase fire risk because they leave behind dry branches that serve as tinder. But prescribed burns clear away that fuel, making a combination of thinning and burning the winning approach, the researchers found. It didn’t matter if the combination of treatments had been tried five years or 20 years prior. When thinning was followed by burning, the researchers saw much lower levels of both tree mortality and canopy torching. To save trees, it appears, you have to both cut them and burn them.

“Our study confirmed that thinning and burning treatments can make a huge difference for fire severity,” says study author Kristen Shive, a fire ecologist at the University of California-Berkeley.

Study plots that were subject to no management before the Dixie Fire had a 58 percent chance of losing all of their trees in the inferno, while plots that had two-thirds of their trees removed before the wildfire, without burn treatment, suffered a 48 percent chance of losing all of their trees. But in areas that were managed through first tree removal and then prescribed fire, the odds that the megafire killed all the trees on the plot sank to just 4 percent.

Since weather and topography also influence how severely a fire burns, Shive and her colleagues statistically analyzed how these factors contributed to the prevalence of grove-annihilating fire. They found that trees on steeper slopes were more vulnerable to tree-killing fire, but that weather did not play an important role once treatment approaches were taken into account. The results were published in Forest Ecology and Management.

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To save trees, it appears, you have to both cut them and burn them.

Fires used to sweep through the northern Sierra Nevada about every decade, consuming the forest understory. This created grassy woodlands full of large, widely-spaced trees whose branches soared above the flames. But a century of fire suppression and the end of Indigenous cultural burning has turned many forests into tinderboxes full of flammable undergrowth.

Now, when fires do ignite, they often grow big and hot enough to kill large trees. Thinning and prescribed fire aim to recreate the fire-resilient woodlands of the past. The kinds of burns typically used to protect forests include pile burns, where cut branches and logs left over from thinning are piled up and set on fire under controlled conditions, and broadcast burns, where low intensity fire spreads across a forest floor or grassland.

“Fire is the key component,” says Travis Woolley, forest ecologist at the Nature Conservancy who did not participate in the study. In fact, prescribed fire alone often works as well as a combination of thinning and fire in reducing the risk of a severe burn, a review study by Woolley found. But thinning is still valuable because it helps the trees survive drought, enhances biodiversity, and can make wildfires spread more slowly, he adds.

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Like Woolley, Shive believes that the best way to protect the forests of the Sierra Nevada from wildfires is to burn them more often. Thinning the trees is not enough. “That woody debris on the forest floor is incredibly important for fire behavior,” she says. “Thinning treatments just don’t deal with that in the way that prescribed fire does.”

This year, the California Wildfire Task Force plans to thin trees and conduct prescribed burns on a record 700,000 acres. Despite this progress, Shive acknowledges that forest treatments have been hampered by steep costs and the sheer ruggedness of the Sierras. But whether the flames are intentional or uncontrolled, fire is coming.

Lead photo: Brian Gailey Photography / Shutterstock

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Mark Degraff

Posted on September 8, 2025

Mark DeGraff is a science journalist who specializes in ecology and biodiversity. His work has appeared in Mongabay, Eos, Mountain Journal, and many other outlets.

ENVIRONMENT | VIEW ON WEBSITE

Cities Obey the Laws of Living Things

All towns, big and small, are animals

By Elena Kazamia    September 5, 2025

Who would disagree with Dickens that London’s green spaces are the city’s “lungs?” A city is an animal that sleeps, although some never do, like New York City or Hong Kong. All cities are creatures of a sort. Some have multiple “faces” they present to the world, most have a “beating heart” where the action unfolds, and it is a rare city that lacks a dark “underbelly.”

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The analogy of city as living organism is so established, in fact, that it has crossed over into the realm of scientific inquiry. For at least a decade, researchers have been attempting to decode what lessons for sustainable planning could emerge from thinking of cities as living breathing beings.

Now a team of scientists from the Ecole Polytechnique Federale de Lausanne (EPFL) has found that all cities—whether Tokyo, Lagos, or Zurich—operate according to predictable principles that govern animal biology in the natural world. In the process, they challenged a longstanding assumption: that bigger cities are more sustainable than small ones.

“Bigger cities are often considered ‘better,’” says Gabriele Manoli, a study author and head of EPFL’s Laboratory of Urban and Environmental Systems, in an email.  “Yet, these laws depend on the definition of a city.” The findings, reported in the Proceedings of the National Academy of Sciences, could influence how urban planners design the cities of the future.

Cities self-organize as they grow regardless of context and without central planning.

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Planners have long postulated that bigger is better because large urban areas require fewer resources and energy per capita and generate more wealth. But this was difficult to model because of the ad-hoc way city boundaries are often drawn. Where does the true edge of a city lie? To resolve this problem, Manoli and his colleagues “re-scaled” 100 cities around the globe, breaking them down into units they called pixels that could be more equitably compared across variously sized urban areas.

Then they crunched millions of data points from these different city units and found a scaling law that connects population size to transport networks and economic activity and CO_2 emissions. The relationship between these variables follows the same curve for all cities, large and small, they found, and echoes Kleiber’s Law, a principle that emerges in biology when the sizes of animals are viewed in relation to their metabolic rates.

In the 1930s, Max Kleiber found that the energy that animals required daily to sustain their bodies (their metabolic rate) scaled in proportion to their size. Mice have a lower metabolic rate than elephants, and tiny microscopic creatures require less energy still. The law has proven a useful tool.

Veterinarians use Kleiber’s Law to determine how much medicine to give an animal, while conservation scientists use it to assess the needs of different species. By simply knowing an animal’s size, they can deduce its metabolic rate, and figure out how much food and water it requires to survive. This helps in managing ecosystems and wildlife reserves to ensure a habitat can support a specific animal population.

For cities, population size is akin to an animal’s mass, economic activity to the animal’s metabolic rate and roads to its circulatory system, the researchers propose. The relationship is universal and independent of geographical, political, and historical differences, they say: Cities self-organize as they grow, naturally optimizing for energy flow and resource distribution, regardless of context and without central planning.

The authors of the study hope that for cities, the relationship revealed in the study may help urban planners with sustainable design. “Thanks to the vast amount of data available, cities offer a fertile ground to test new theories inspired by biology and ecology,” says Manoli.

Perhaps the new math will give planners a better handle on how to keep the beasts that are our cities humming as they grow and evolve.

Lead image: Alicia Crespo Montañes, EPFL URBES

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Elena Kazamia

Posted on September 5, 2025

Elena Kazamia is a science writer from Greece. She has a master’s degree in conservation from University College London and a Ph.D. in plant sciences from the University of Cambridge in the U.K.

Evolution

- When Nature Burst Into Vivid Color

EVOLUTION | VIEW ON WEBSITE

When Nature Burst Into Vivid Color

Which came first: colorful signals or the color vision needed to see them?

By Molly Herring    September 9, 2025

The natural world is awash with color, and many of these vibrant hues are meant to be seen. Apples blush red to coax animals to spread their seeds, lavender blooms are violet to lure in pollinating bees, and male peacocks trailed by flashy blue trains more successfully attract mates.

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However, the world is colorful only for some of us. These vivid signals can be perceived by animals that can see in color; to organisms that have limited or no color vision, many of these bright colors don’t mean anything at all. This raises interesting evolutionary questions. Which came first: colorful signals or the color vision needed to see them? And when did these optical signals emerge and take off, painting the natural world in the kaleidoscopic spectrum we see today?

“Some birds are red, some snakes are red, and some plants have red fruits. In each of these cases, the red coloration serves as a signal,” said Zachary Emberts, an evolutionary biologist at Oklahoma State University. “This led us to wonder: What was the initial function of conspicuous coloration, like red, and color vision?”

Emberts and his former postdoctoral adviser John Wiens, an evolutionary ecologist at the University of Arizona, combed through research encompassing hundreds of millions of years of evolutionary history to offer a scientific answer to the chicken-and-egg question of color. The researchers used the fossil record and phylogenetic trees—timelines of species emergence that are based largely on modern traits—to infer when colorful signals may have first emerged in plants and animals. Then they tested their hypothesis that color vision and colorful signals evolved together.

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“What I love about this paper is the ambition and confidence to pursue big questions and explore ideas that will inevitably involve speculation,” said William Allen, an ecologist who studies sensory systems at Swansea University in Wales and was not involved in the new study. “There is a tendency for science in the 21st century to focus on applying analytic techniques to data, and this can sometimes be at the detriment to deep thought, natural history, and curiosity.”

The Evolution of Color

As a graduate student at the University of Texas, Austin, Wiens was fascinated by pretty animals. For his dissertation, he studied blue-bellied lizards, which have earth-toned backs and sapphire undersides, to examine how sexual signaling might have evolved. He built a phylogenetic tree of lizard species and was fascinated to see that the males’ blue patches, which signal fitness to females, frequently disappeared and reappeared along the evolutionary timeline, perhaps because females stopped picking up on the signals in some lineages. That project piqued his interest in how the production and recognition of color signals might have evolved.

COLOR DETECTIVE: As a graduate student, John Wiens first encountered colored patches used by lizards as a sexual signal. Decades later, he resumed his exploration of the use of color by organisms. Credit: Ramona Walls.

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There are some costs to color. For example, a vivid signal to attract a mate may attract predators as well. But the persistence of color throughout evolutionary history suggests that, for many organisms, the information it communicates is beneficial enough to outweigh the cost. However, without color vision, the value of maintaining distinctive coloration would vanish; indeed, there would be little reason for it to evolve in the first place. That made Wiens wonder why different species evolved the ability to see color—perhaps to find colorful fruit, flowers, or mates? Did those palettes even exist at the time?

He didn’t investigate right away, and spent a few decades studying evolution in reptiles and amphibians. But the questions kept pestering him. So Wiens, working with Emberts, tried to reconstruct the evolutionary histories of color in living things. The pair scoured the literature to compile fossils and phylogenetic trees, built by themselves and others, to put rough dates on when these traits might have emerged in deep time. It’s an imperfect method, but generally, if many closely related modern species have the same trait, researchers can infer that it evolved in a common ancestor.

Some components of color vision have been lost over evolutionary time.

They considered a few possibilities for how these evolutionary developments might have played out. Perhaps color vision evolved first for some non-signaling reason, such as detecting shelter, food, or landmarks. But the pair hypothesized something more dynamic: that color vision evolved around the same time as a color signal, such as flashy fruit, attractive flowers, mating colors, or warning signs.

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The data revealed that distinctive colors appeared in life around 300 million years ago in fruits and seeds. Colorful flowers likely came next: Most researchers pin the most recent common ancestor of all flowering plants to the Triassic Period, between 140 million and 250 million years ago. “There’s a lot of disagreement about how old flowering plants are,” Wiens said, “but the median of the estimate is around 200 million years.”

NATURAL COLORS: Clockwise from top left: Female blue moon butterflies favor males with iridescent blue spots; golden poison frogs use yellow coloration to advertise skin toxins; redwings prefer bilberries that reflect UV light; Himalayan balsam flowers attract violet-sensing bees. Photos by Huaykwang, Thorsten Spoerlein, Valentyn Volkov, and Oli S photography / Shutterstock.

Then, about 130 million years ago, it appears that animals started using colors to ward off predators. That’s when the first hint of warning coloration appears in the fossil record, in a cockroach fossilized in amber (the specific color is not entirely clear, Wiens said). Around 105 million years ago, a group of butterflies likely flashed yellows, reds, and oranges as caterpillars; Wiens and Emberts inferred these ancestral colors from colorful descendants that exist today.

While, phylogenetically, colorful flowers seem to have a single origin, the warning hues are present in nine different phyla, which means they likely evolved independently again and again—maybe even hundreds of times, Wiens said. They have evolved even in species that don’t have color vision, likely because their predators do.

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Finally, animals started wearing color to attract mates. About 100 million years ago, two types of fish—long, silvery species such as needlefish, and ray-finned species such as killifish—likely gained color, based on phylogenetic data from living species. These kinds of sexual signals also may have evolved hundreds of times across vertebrates and arthropods, the researchers found, but unlike warning colors, these cues exist only in species with color vision. “You have to be able to see the colors of your conspecifics [members of the same species] for those sexual signals to work,” Wiens said.

To his surprise, the emergence of these color-coded signals didn’t even come close to the earliest appearance of color vision. Color vision likely evolved twice independently, he found, and around the same time: between 400 million and 500 million years ago in arthropods, such as insects, and in backboned animals, such as fish. That places the evolution of color vision 100 million or 200 million years before any color signals.

Credit: Mark Belan / Quanta Magazine

In the animal kingdom, there is incredible variation in visual perception. What an animal sees depends on the structure of its retina and its neural visual processing system. Most insects can see ultraviolet, blue, and green light, but there is wide variety among arthropods; mantis shrimp eyes have up to 12 different channels of color, revealing the ultraviolet spectrum and polarized light. The ancestor of living vertebrates could likely detect red, purple, blue, and green—an ability that was maintained in lizards, birds, lampreys, and lungfish, among other vertebrate groups, Wiens said. But some components of color vision have been lost over evolutionary time. Hagfish can’t detect red. Sharks can’t see blue. Human eyes have three photoreceptor cones that allow us to make out blues, greens, and reds, but dogs and rabbits have only two cones, which reduces the number of shades they can distinguish.

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Wiens and Emberts’ data supports the hypothesis that color evolved for some as-yet-unknown reason before any of these flashy signals. “It was color vision first, then fruit, then flowers, then warning signals, and then sexual signals,” Wiens said.

Coming and Going

The researchers’ effort to reconstruct deep time is admittedly imperfect. Colors don’t readily fossilize, and when they do, scientists can’t infer the color’s function unless the animal has living descendants. And for all the data they involve, evolutionary trees are inherently speculative. Some traits can evolve multiple times in different lineages. For example, juniper berries and blueberries are both blue, but their ancestors may have developed that coloration separately. Other traits can come and go, like the lizards’ blue belly patches. If we know that signals can disappear and reappear over millions of years, it’s hard to be certain that a common ancestor actually possessed that shared trait.

“This evolutionary lability has the effect of blurring whether a color adaptation existed in deep time or not,” Allen said. “If, for example, a lineage gains or loses warning color once every million years, it is very difficult to infer from the traits of current species whether an ancestor living hundreds of millions of years ago had warning color.”

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A vivid color, whether it’s a pure pigment or a reflective structure, takes action to organize.

That’s why using phylogenies to date the origin of a function has inherent uncertainties. “Looking at what’s around nowadays doesn’t tell you very much because it’s just coming and going,” said the neuroscientist Daniel Colaco Osorio, who studies animal vision at the University of Sussex and was not involved in the study. But Wiens insists that the only way we can know that traits disappear and reappear is by using evolutionary trees to test this kind of hypothesis. This is the best method we have to peer into the evolutionary past from the present, he said. “How does one claim [that traits come and go] without doing a study like ours?”

To be clear, there was color in the world before color vision. Plant leaves, for example, reflect green light even if there are no eyes to see it. In 1999, Osorio studied color vision in chicks and suggested that it serves a more general purpose. “It could just be recognizing objects or navigating around the place,” he speculated. A prevailing theory was popularized in 2000, when Vadim Maximov proposed that color vision evolved to aid vertebrates in low-light aquatic conditions. The presence of two classes of photoreceptors, he argued, helped reduce the “flicker” beneath the surface of shallow water, which helped aquatic creatures chase prey and avoid predators. That would explain why the building blocks of color vision arose just after the active predatory lifestyle was mastered, but well before there was a more obvious use for it.

Color signals maintained by living things across evolutionary time are of a different character. In 2019, Osorio suggested that a vivid color, whether it’s a pure pigment or a reflective structure, takes action to organize. They are therefore evidence of work against the forces of entropy; it’s generally something an organism evolved for a reason. “If you empty the contents of your vacuum cleaner bag, it’s kind of gray because everything’s mixed together,” he said. “If you have a structure with meaning or purpose, that can be indicated by having a bright or pure color … which isn’t particularly tied to the meaning of the signal.” His research has demonstrated mathematically that what looks like a vivid, pure color to one animal is likely to look vivid and pure to another, regardless of their visual system.

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Some questions are ultimately unknowable—but can still be useful or enjoyable to ask. Wiens and Emberts’ review is a step toward understanding why the natural world is so colorful. Plus, Wiens found that over the past 100 million years, there’s been an explosion in warning and sexual signals driven by signaling between birds, lizards, and fish. He believes that this trend might continue—which suggests nature is on track to get even more dazzling.

For more, listen to The Quanta Podcast: Apple | Spotify.

This article was originally published on  Quanta.

Lead image: A mantis shrimp displays striking coloration and can see it better than most animals: Its eyes have 12 color channels that can perceive the ultraviolet spectrum and polarized light. Credit: Samy Kassem / Shutterstock.

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Molly Herring

Posted on September 9, 2025

Molly Herring is a science writer based in Brooklyn, NY. She holds bachelor’s degrees in biology, global studies, and English from UNC Chapel Hill and a master’s in science writing from the University of California, Santa Cruz.

Health

- Our Dark, Unvaccinated Future

HEALTH | VIEW ON WEBSITE

Our Dark, Unvaccinated Future

Diseases that cause suffocation, paralysis, and childhood death are poised to come surging back

By Megan Scudellari    September 5, 2025

On the final night of her pediatric residency in the mid-1970s physician Kathryn Edwards stood by the bedside of a dying toddler. A bacterial infection, Haemophilus influenzae type B or Hib for short, raged through the young girl’s bloodstream, inflaming the membranes around the brain and spinal cord. That night, realizing a vaccine could have saved the child’s life, Edwards resolved to devote her career to developing vaccines for children.

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In the 1970s and ’80s, 20,000 children younger than 5 became infected with invasive Hib each year in the United States, and about 1,000 died. In 1987, the introduction of an effective Hib vaccine soon dropped those numbers by 99 percent, down to single digits per year, the cases almost exclusively occurring in unvaccinated or undervaccinated children.

But today, more than 45 years after that terrible night, Edwards fears that the pre-vaccine era could return. “We are in a very scary time,” says Edwards, an expert in childhood respiratory disease and vaccine safety who recently retired from Vanderbilt University Medical Center. “We have to realize these diseases are the bad ones. We really don’t want them to come back.”

But they are back. Diseases that the U.S. had all but eliminated decades ago through mass vaccination campaigns have returned. Measles is surging and whooping cough is close on its heels, with cases tripling in many states over the past year. That’s an ominous trend, says Amy Edwards, an associate professor of pediatrics at Case Western Reserve University School of Medicine. “When you see whooping cough on the rise and measles on the rise, you know the vaccination rate is high but dropping. Then come the rest.”

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Vaccinations in the U.S. would plummet. Death, illness, and disability would surge.

“The rest” is a long list of names that were once destined for the dustbin of history—polio, diphtheria, hib disease, rubella, and more—each accompanied by horrible complications, including blindness, brain injury, paralysis, and life-long chronic illness and disability. “We have tens of thousands of history and medical books that describe the horrors of some of these diseases,” says Daniel Pastula, chief of neuroinfectious diseases and global neurology at the University of Colorado. “And we don’t see them anymore because of vaccines.”

Vaccines protect both the vaccinated individual and the population at large, because if enough people are immune to an infectious disease, that contagion cannot easily spread from one person to another. Yet vaccination rates that began declining during the COVID-19 pandemic have continued to drop, putting the population at risk for the resurgence of these illnesses. But how quickly could that happen, and what are the most pressing dangers?

Through discussions with doctors, infectious disease scientists, and public health officials—including some who witnessed the damage wrought by these illnesses before vaccines were available—Nautilus explores what could happen next, and how it might be prevented.

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Cascading Contagions

Declining vaccination rates might paradoxically be a consequence of vaccines’ incredibly successful and safe track records: Most people alive today have no first or even secondhand experience with many of these illnesses. But other factors are also at play, including vaccine hesitancy fueled by rampant vaccine misinformation.

Additionally, work by the current U.S. Secretary of Health and Human Services, Robert F. Kennedy Jr., to rewrite decades of vaccine policies is actively changing the landscape of vaccine availability and access. For example, experts interviewed for this article unanimously expressed support for—and fear of losing—the Vaccines for Children Program, established by Congress in 1994 to provide vaccines to low-income children at no cost. That program alone distributes more than 70 million pediatric vaccines each year and is estimated to have prevented 508 million illnesses, 32 million hospitalizations, and saved more than 1.1 million lives since its inception.

The program is funded and run by the U.S. Centers for Disease Control and Prevention (CDC), which has experienced major funding cuts and layoffs under Kennedy’s supervision. It covers the cost of vaccines recommended by the Advisory Committee on Immunization Practices (ACIP) —a body that Kennedy gutted in June and filled with his own appointees, some of which have expressed vaccine skepticism. If the administration or ACIP were to restrict or abolish the Vaccines for Children Program or the vaccines it offers, vaccinations in the U.S. would plummet. Death, illness, and disability would surge.

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Already, vaccination rates in the U.S. are dropping. Declines in vaccination began during the pandemic, when social isolation and disruptions in healthcare coverage led to fewer people being vaccinated for a host of diseases those years. But even as the pandemic ended, vaccination rates continued to decline. In the 2024-2025 school year, for example, record numbers of unvaccinated children entered schools: More than 280,000 kindergarteners in the U.S. did not complete the measles, mumps, and rubella (MMR) vaccine series. Compared to the year before, exemptions from one or more vaccines among kindergartners increased in 36 states and DC, with 17 states reporting exemptions exceeding 5 percent. And there is no end in sight. In early September, Florida’s surgeon general announced that the state planned to end all vaccine mandates, including those for schoolchildren.

If vaccination rates continue to drop, eliminated diseases will come roaring back. First to return: measles.

Measles

Measles is one of the world’s most contagious diseases. It is especially dangerous for young children and people with weakened immune systems, and the complications are severe, including deafness, blindness, and brain damage. Additionally, measles poses a unique threat to the immune system: Like a guided missile, measles virus specifically targets immune system cells responsible for remembering past illnesses. So following measles infection, an individual’s immune system has severe amnesia for two to three years, with little memory of how to protect itself from common pathogens. This, in turn, leads to an overall higher risk of death from other infections.

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In 2000, the World Health Organization declared the U.S. measles-free, but the tide quickly turned. Since 2019, MMR vaccination rates have declined annually nationwide. As of September 3, more than 1,431 measles cases have been reported this year—more than any year in three decades—and there are still four months left in 2025. Cases are rising so quickly, in fact, that earlier this year, the Johns Hopkins Bloomberg School of Public Health and the International Vaccine Access Center released a U.S. Measles Tracker—a mapping tool that is eerily reminiscent of COVID-19 trackers during the pandemic.

We’ve reached a pivotal point in this cascade of returned diseases.

“We’re really on a tipping point for measles,” says Nathan Lo, an assistant professor of infectious diseases at Stanford University. “It is already at risk for returning to become a commonplace disease.” At current vaccination levels, measles will become endemic—that is, consistently present and circulating in the U.S. population—in 25 years, resulting in more than 850,000 cases and 2,250 deaths, according to an April modeling study from Lo and Stanford epidemiologist Mathew Kiang. If there is a 10 percent decline in vaccination rates, measles could skyrocket to 11.1 million cases over the next 25 years. And if there were a dramatic 50 percent decline, measles would be endemic in just 5 years, with 51.2 million cases over a 25-year period.

Whooping cough

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Whooping cough, also called pertussis, is another vaccine-preventable disease that’s been raging back: As of Aug. 23, 2025, there have been 19,159 reported cases of pertussis in the U.S. this year—almost 2,000 more than the same period last year, according to the CDC. At this rate, the U.S. could reach 70,000 pertussis cases by the end of the year, according to one recent prediction.

Pertussis, with its uncontrollable, violent coughing, is likely to spread quickly because it is almost as contagious as measles. Protection against pertussis from a combination vaccine against tetanus, diphtheria, and pertussis—a shot routinely administered to people of all ages, including during pregnancy and as a standard series starting in infancy—declines quickly, from 70 percent efficacy in the first year after vaccination to less than 10 percent after four years. And while vaccinated individuals rarely show symptoms, they can still transmit the bacteria to others.

Pertussis can be severe in infants, especially those who are too young to be immunized. But current CDC numbers indicate that roughly 40 percent of expectant mothers do not get vaccinated against it. When that happens, or when a parent declines to vaccinate their infant with the three recommended doses, that infant is immediately at risk. In 2024, six infants in the U.S. died of whooping cough, and that number is poised to rise rapidly if more parents opt against vaccination, or vaccine mandates are weakened,  as the bacteria spreads.

Influenza

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It often gets passed over because of its common seasonal influx, but influenza still causes some 6,300 to 52,000 deaths each year in the U.S. And this infectious agent is just a season away from spiking to record levels if vaccination rates decline further.

Last year’s hospitalization rate during flu season was the highest it has been in 15 years, and vaccination rates for flu have been steadily declining year after year. That trend will likely be exacerbated by Kennedy’s order delivered earlier this year to the CDC to halt a popular publicity campaign encouraging people to get the seasonal flu vaccine. “Flu is definitely something that can quickly come back and be more severe,” says Kathryn Edwards. Flu vaccination is recommended each year for everyone over 6 months of age.

Rubella, Hib, and meningococcal disease

After the speedy reemergence of measles, pertussis, and flu, experts forecast the slower rise of three more vaccine-preventable diseases: meningococcal disease, a bacterial infection that leads to outbreaks of meningitis and can be deadly within hours of symptom onset; Hib disease, the bacterial infection known to spread in daycare centers, and which was once the most common cause of meningitis; and rubella, a viral illness that can cause serious defects or death in developing fetuses. In the Stanford modeling study, if childhood vaccination rates drop an additional 20 percent, rubella rates begin to climb. “That’s really a scary future that we hope does not come to pass,” says Lo.

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Pneumococcal disease, mumps, chickenpox, and hepatitis

One of the harder-to-spot outbreaks will be pneumococcal disease, says Amy Edwards, as there are more than 100 strains of the causative bacteria. And pneumococcal vaccines—which are recommended for children under 5, adults over 50, and others with certain risk factors—protect against only the 15 to 20 most deadly strains. Because there are already occasional outbreaks in the U.S. from strains not covered by the vaccines, Edwards notes, public health officials might not immediately notice if one of the more invasive, deadly strains, typically prevented by vaccination, begins to take hold.

Pneumococcal bacteria spreads through direct contact with saliva or mucus, and serious infection can lead to pneumonia, meningitis, or bloodstream infections. In 2024, 14 inmates at a correctional facility in North Carolina became ill with suspected pneumococcal disease. A CDC investigation identified the cause as serotype 4, a serious strain that causes high percentages of pneumococcal disease. That strain was not one of the strains included in the most recently recommended vaccine, PCV21.

An influx of patients with vaccine-preventable diseases will strain already struggling hospitals and medical centers.

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As if this list weren’t already long enough, next will come mumps and chickenpox, which have rare complications, including brain inflammation and severe skin infections, respectively, and hepatitis B, which used to be one of the most common causes of liver failure and sometimes required liver transplants in babies.

We’ve reached a pivotal point in this cascade of returned diseases. If Americans are able to improve vaccination rates over the next five years, that will be the worst of it. But if vaccination rates continue to drop, “we start to get into some of the scarier ones,” says Amy Edwards. Namely, the resurgence of polio and diphtheria.

Polio

Kathryn Edwards remembers being in elementary school when a friend became seriously ill with polio, and Edwards walked around her neighborhood collecting dimes in the original “March of Dimes” to fund the development of a polio vaccine at the behest of President Franklin D. Roosevelt. It was the era of “polio summers,” when towns closed movie theaters, public swimming pools, schools, and churches to prevent transmission of the virus, which affects nerves in the spinal cord or brain stem, leading to paralysis, trouble breathing, and sometimes death.

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Largely thanks to an oral version of the vaccine, the U.S. eliminated polio in 1979. Since routine immunization against polio was introduced worldwide in the 1970s, the global incidence of cases of the disease has decreased by 99 percent. But predicting what might happen in the U. S. if polio vaccination rates were to dramatically decline is shrouded in some uncertainty, due to a change in the type of vaccine administered.

Until 2000, children in the U.S. were vaccinated with an oral polio vaccine (OPV), made from live polio virus in a weakened form. That vaccine protects the immunized person and, because that person sheds weakened virus, helps expose and immunize those around them as well.

On rare occasions (about 1 in every 2.4 million doses of OPV), the weakened virus reverts to a “strong” virus and can cause a case of the disease, occasionally leading to paralysis. Therefore, since 2000, in an effort to eradicate poliovirus globally, the U.S. switched to using an inactivated polio vaccine (IPV), which cannot revert to cause the disease. That means every immunized person born in the past 25 years has received the IPV vaccine, which does not offer the benefit of secondary protection. Because of this, we don’t fully understand what percentage of a community needs to be vaccinated to prevent the spread of polio, says Roland Sutter, who served as chief of the Polio Eradication Branch of the CDC from 1997 until 2001 and then as a coordinator of the Global Polio Eradication Initiative with the World Health Organization. If polio vaccination rates were to considerably decrease, “it’s quite unpredictable what is going to happen,” he adds. “This is uncharted, new territory for polio.”

Diphtheria

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In the 1920s, diphtheria was one of the most common causes of illness and death among children in the U.S. This serious bacterial infection creates a gray, leather-like coating in the mucus membranes lining the throat and nose, obstructing breathing. “It is terrifying to watch a child not be able to breathe,” says Amy Edwards, who has treated children with diphtheria in sub-Saharan Africa. “Even if with modern technologies we can save them, it is horrible to watch a kid be in the ICU for a week.”

“We are a stone’s throw or a plane ride away from whatever infectious disease emerges next.”

Thanks to widespread uptake of the diphtheria vaccine, the last U.S. confirmed case of respiratory diphtheria was reported in 1997, though the bacteria that cause the disease still circulate in other countries. According to the Stanford modeling study, if vaccination coverage drops 35 percent below current levels, diphtheria will begin a slow but steady return.

Reversing Course

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While it is now often—but not always—possible to save children sick with diphtheria or many of the other vaccine-preventable illnesses, they often require intensive healthcare interventions. For instance, babies under 6 months old with whooping cough need prolonged pediatric ICU stays, often hooked up to a ventilator or even a heart-lung bypass machine. Because of this, an influx of patients with vaccine-preventable diseases will strain hospitals and medical centers already struggling with staffing and funding shortages since the pandemic. And these live-saving procedures are not without risks and potential long-term health effects.

Additionally, new restrictions on Medicaid payments included in President Donald Trump’s sweeping budget bill signed into law this summer, will likely lead to significantly less revenue for hospitals, which will in turn have fewer staff and resources to care for patients. “If we start taxing a healthcare system that is already broken with sicker and sicker kids, you’re putting pressure on a system that’s already crumbling,” adds Amy Edwards.

Another overarching concern is the spread of vaccine-preventable illness around the rest of the world. In June, when Kennedy withdrew a $1.2 billion funding pledge from GAVI, a leading international vaccine organization, global health leaders were stunned and worried. The U.S. cannot keep itself safe from infectious diseases in isolation, says Sutter. If international health systems are less equipped to prevent infectious diseases, those diseases will spread, mutate, and arrive on U.S. shores. “This is one world,” says Sutter. “We are a stone’s throw or a plane ride away from whatever infectious disease emerges next.”

Facing the potential return of these once-prevalent diseases, it feels at once bewildering and reassuring to know we already have the tools to prevent them. “Vaccinations are the greatest testimony to scientific advancements in medicine, particularly pediatric medicine, that we’ve ever seen,” notes Kathryn Edwards. “We have got to work very hard to make sure some of these things that could happen, don’t happen.”

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Parents want to keep their children safe and healthy, and most parents trust their primary care physicians, so experts recommend that pediatricians and other healthcare providers always ask if children are fully vaccinated. And parents should feel encouraged to discuss the relative risks and benefits of vaccines and infectious diseases with their doctors, says Pastula. “Any healthcare provider would be happy to walk through that,” he says.

The good news is that even a small boost in vaccination rates could make a big difference. For example, a modest 5 percent increase in vaccination rates over 25 years would reliably prevent measles from returning to endemic levels, says Lo. “A pretty small fraction of the population could make a big difference for the United States.”

Preventing a new wave of old diseases will require the government and public to support and raise vaccination rates to high coverage, yet all signs suggest that U.S. health agencies and public sentiment continue to head in the opposite direction. “I worry about it greatly,” says Kathryn Edwards. “We need to share the clear message that the benefits [of vaccines] are really much greater than the risks.”

Because, at the very least, we can all agree on one thing, adds Amy Edwards: “Kids shouldn’t die. Any child dying is one too many.”

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Lead image: Thechildrenshospital / Wikimedia Commons

Megan Scudellari

Posted on September 5, 2025

Megan Scudellari is a science writer based in Boston, specializing in the life sciences. Her work has been featured in the Boston Globe, Nature, Newsweek, and others. She is also co-author of a college biology textbook, Biology Now.

History

- DNA’s Death Notice

- These Early Humans Walked 8 Miles for the Perfect Rock

HISTORY | VIEW ON WEBSITE

DNA’s Death Notice

See original manuscripts, letters, photos, and jokes from luminaries like Rosalind Franklin, Aaron Klug, and Linus Pauling

By Bob Grant    September 15, 2025

Imagine being able to see what Rosalind Franklin saw, when she and a graduate student first imaged the structure of DNA—and then study the intimate handwritten notes on the back of it.

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Now, in fact, you can. A trove of landmark historical science images and artifacts (which also include notebooks, handwritten annotations, and even an inside joke or two), have recently joined the collection of the Science History Institute, a Philadelphia-based museum and library, which is working on making them widely available to the public.

DNA’S FIRST CLOSE-UP: This historic DNA X-ray diffraction pattern, known as “Photograph 51,” was generated in 1952 by Rosalind Franklin and her grad student Raymond Gosling at King’s College London. Annotations by Franklin and her colleague Aaron Klug grace the back of the image, which finally resolved the long standing question of DNA’s structure, the double-helix. Image courtesy of the Science History Institute.

The crown jewel of the collection so far is, of course, the image produced in 1952 by X-ray crystallographer Rosalind Franklin and her grad student Raymond Gosling showing the double-helical structure of a DNA molecule. The “Photo 51” image, which was Franklin’s own personal copy and is annotated with handwritten notes on the back, will be the centerpiece of a new exhibition at the Science History Institute museum planned for fall 2027, which will mark the 75th anniversary of “Photo 51.”

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The newly acquired collection features laboratory devices used by Franklin and Gosling in their seminal research, as well as letters, photographs, and other materials from the pair and from other notable molecular biologists of the era. You can also find pictures of Franklin on vacation and even a death notice, written in jest, for DNA’s helix structure (a delightful reminder that even Nobel-worthy scientists like to have a bit of fun here and there).

VACAY BEFORE BREAKTHROUGH: This vacation shot of Franklin was taken by her friend and collaborator in 1950, two years before she created “Photograph 51.” Photo by Vittorio Luzzati, courtesy of the Science History Institute.

“We see this as a seed collection that will inspire further growth as we preserve the history of the life sciences for a global audience,” David Cole, president and CEO of the Science History Institute, said in a statement. The History of Molecular Biology Collection was recently acquired from the L. Craig Venter Institute, and staffers at the Science History Institute are at work digitizing the materials it contains, providing free access through their website.

In the meantime, there are more than 140 items already available to peruse and glimpse the inner workings of the people who coaxed revolutionary insights from the hidden worlds that surround us.

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Lead image courtesy of Science History Institute

Bob Grant

Posted on September 15, 2025

Bob Grant is the deputy editor at Nautilus.

HISTORY | VIEW ON WEBSITE

These Early Humans Walked 8 Miles for the Perfect Rock

The quest for better tools is more ancient than we thought

By Sara Kiley Watson    September 5, 2025

Imagine walking miles and miles across dangerous terrain frequented by sabertoothed cats just to find the right rock. Around 2.6 million years ago, a group of early hominins in East Africa started to do just that. They decided they needed better tools with which to prepare meals, so they began trekking long distances across grassy open woodland to get the raw materials: rocks that were durable but brittle, mostly quartzite, rhyolite, quartz, chert, and granite. Then they lugged their heavy quarry back across that same formidable landscape for shaping at home.

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These hominins lived in Nyayanga, a valley in western Kenya that sits on the banks of Lake Victoria and in the shadow of Homa Mountain, and the tools they crafted are known to archaeologists as Oldowan tools, some of the earliest standardized stone tools on Earth. Scientists believe these Oldowan tools were used for things like cutting, scraping, and pounding to prepare plants and butcher hippo meat. But they weren’t certain where the hominins who used them got their materials.

This is really early in the archaeological record.

Now, a team of researchers has revealed that the hominins in Nyayanga were the first to forage for high-quality stones over long distances. In some cases, these treks extended more than 8 miles, farther than many modern people walk in a week, which suggests a high level of planning and forethought. Such are the findings of a recent study published in Science Advances, which puts the timing of such sophisticated tool-making behavior some 600,000 years earlier than most scientists had previously thought.

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“This is really early in the archaeological record to have tool makers traveling those distances for raw material sources,” says study author Emma Finestone, an associate curator at the Cleveland Museum of Natural History. The ability to plan out resource use in this way was likely critical to the rise of large-scale food sharing among hominins, according to Finestone and her colleagues.

READY TO ROCK: This stone knife from more than 2 million years ago was used for basic chopping and scraping. It belongs to the Oldowan family of tools, which were among the first standardized tools and were deliberately crafted to have sharpened edging. Credit: Appio Studios / Shutterstock.

In the early days of human evolution, the Nyayanga valley possessed a winning combination for settlement: fresh water, food, and shade. But its stones were not great for making sharp and durable tools. The rocks around the valley were soft and dulled easily, says Finestone. When the team of researchers analyzed the geochemistry of 401 different artifacts from the site, as well as how rock traveled through rivers in the valley at the time, it became evident that the residents of Nyayanga were sourcing raw materials from many miles away.

Scientists had previously believed that the first hominins to travel long distances to find stones for tool making did so about 2 million years ago in a region of Kenya known as Kanjera, not far from Nyayanga on the Homa Peninsula. But the new findings suggest that Kanjera’s traveling stone artisans may not have been the first.

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Oldowan tools were distinct from the tools that nonhuman primates crafted and used: The hominins who pounded them into shape purposefully removed flakes of the stone core to create a sharp edge, perfect for slicing up hunks of prey for dinner. Nonhuman primates were, and still are, less deliberate about how they shape sticks and stones for tasks.

It is important to note that members of the Homo genus weren’t the only hominins in the Nyayanga area 2.6 million years ago. Paranthropus, a genus of extinct hominin, were also around, which means that the transport of rocks to make sharp tools might not have been exclusive to modern day humans’ most direct ancestors. What it does suggest, however, is that the quest for better tools is even more deeply ingrained in what it means to be human than we thought, says Finestone.

“We forget that we are also animals that are evolving and adapting and surviving,” she says. For millions of years, humans have been striving to perfect the tools and technologies needed to flourish in harsh environments.

Lead image: Ique Perez / Shutterstock

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Sara Kiley Watson

Posted on September 5, 2025

Sara Kiley Watson is a climate and science journalist currently based in the Netherlands.

Philosophy

- Why I Became a Birdwatcher

PHILOSOPHY | VIEW ON WEBSITE

Why I Became a Birdwatcher

Learning to look past indifference and into the mystery of life

By Adam Nicolson    September 10, 2025

The first time I met a bird close-up, it was dead. A raven. Even seeing it on the side of the mountain road in Crete was a shock: a large, dark splayed body the size of a small dog. I stopped the car and got out, not quite certain if I would find a wounded animal, enraged at its fate and frenzied in pain. But it was properly dead. Whatever it had once been had left. Holding its rigid form—all looseness and flexibility gone; it was as stiff as a dried cod—feeling my way around it, rustling open its wing feathers, pushing through the soft plumage on its nape and back, was like exploring a derelict house. Rafters, furnishings, upholstery, timbers, abandonment. It had been shot and its bill was bloodied in gouts toward the point, yet the midnight blue of its back and wing shimmered in my hands, each sheathing layer overlapping the next in soft-edged scales.

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The bird felt like a miracle of construction: the splitting-axe of its bill, more paleo than any piece of bird-body I had ever seen, capable of crushing the skull of a rabbit in one slow, final closure; the nape that it ruffles and raises in both anger and desire; the spread of the primary feathers in the wing, no matter wasted, each rib as structural as a medieval vault, as fine as necessary, graded in width and strength from outer to inner and from tip to root.

And then the claw, dirty from life, knobbled like a Malacca cane, the darkness giving way, as an undertaker’s shoe might when muddied beside the grave, to a leathered practicality, armored against the world and padded against rock.

The dead bird was not the bird. The body seemed only to have been the means by which the bird could have become itself. But that moment of closeness to such an animal was the beginning of something for me.

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I had never paid much attention to birds. For whatever reason—perhaps because everyday birds were too small, too evasive, too difficult to know, requiring too much patience and too much submission to their ticky little habits—I had not cared about them. Or not bothered to care.

The dead bird was not the bird. But that moment of closeness was the beginning.

My family had never been troubled by them. My father—no naturalist—was always more interested in looking across a bit of country than in what it might be made of. The view was the thing, not the plants or animals in it. As a boy I never chose to understand the birds or tried to learn the songs or calls. I did love seabirds—big, obvious, loud, heraldic, unmistakable—and came to know them on our annual holidays in Scotland, but the birds in the wood or the garden at home remained a blank, a flicker of nothing much, like motes in sunlight.

Why this indifference? Perhaps because attending to the birds seemed marginal to the bigger stories. Perhaps because my father looked down on anything like that. He built himself a gazebo—an 18th-century joke: “I will gaze,” as a fusion of Latin and English—on the corner of the garden from which he could survey a stretch of country “unchanged since Jane Austen saw it,” as he would often say.

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A view, or a landscape as it was always more grandly described, precludes a love of anything else and as the naturalist Mark Cocker described in Our Place, his excoriating 2018 account of the failure of modern nature organizations to attend to the well-being of nature, this view-addiction has presided over a destruction of everything else. Perhaps because of an inherited taste for parkland, carpet has seemed better than vitality, smoothness than mess. The Britain Cocker portrayed has fetishized a “landscape beauty almost devoid of biodiversity … Nature is slipping away from these islands … Not since the last ice age has Britain been so stripped bare of its natural inhabitants.” In common with that presiding culture, I had walked thousands of miles across a diminished Britain without ever truly recognizing what was or wasn’t there.

Later, when I encountered bird people who had spent their years of apprenticeship learning and attending to the birds, I slid past them. I remember in Turkey, making a radio program on Homer with my friend and lifelong birder Tim Dee. As we stood together on the Trojan plain, perched on the slopes of a Bronze Age tumulus known as the Tomb of Achilles, he said he could hear a woodlark singing above us. I began to talk into his woolly microphone about the beauties of that place, its oak woods, its leaning, creaky olive groves, the lionskin of late-summer grasses, the endless, homeless north wind blowing across from the steppes, and said something about “the song of a lark high above us.” Tim stopped me: “Not a lark, a woodlark.” He can never watch a film without agonizing over the presence of the wrong birds at the wrong time of year on the soundtrack.

We started again and I said “lark” again and I remember his frustrated, raised eyebrows and the pursed lips of the radio producer who remains silent, his eyes on the horizon, as his contributors mouth idiocies.

It is a reproachful memory, symptomatic of a certain frame of mind. And so a couple of years ago I decided to embark on an attempt to encounter birds, to engage with a whole and marvelous layer of life that I had lived with in a kind of blindness and deafness for decades.

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I have come to think that the inaccessibility of birds is the heart of their marvelousness.

I wanted to look and listen, to return to Bird School and see what it might teach me. I knew it would be long, slow and bitty. Birds don’t easily offer themselves up and in that way differ from our modern experiences in which the wanted or desired is almost constantly available. Birds move too fast or are too far away. We summon their alarm. Their concealment is occasionally interrupted only by a flickering, transient, uncertain presence. “Nature likes to be hid,” Heraclitus wrote in Ephesus 2,600 years ago and as such birds are the opposite of a landscape view that lays itself out in a kind of horizontal, placid seductiveness. Birds refuse that subjugation. They are often on the run, intent on a life in which the human observer is merely a threat or annoyance. They know how to fly away, neatly like owls or buzzards, with a kind of disdainful calm, or like pigeons with a grand fluster of feathers and noise, or blackbirds with a car-alarm-disturbed-terror- shriek; or to hide and creep, to stay still and silent, like the snipe or woodcock in the most anxious stillnesses in nature, to warn each other of some alien mammal in the neighborhood and to observe us far more than we ever observe them.

Experiments have shown how much they dislike the threat that a human eye represents. They don’t like being looked at, and birds, if you look at them too hard, will fly away. The eyespots on butterfly wings are designed to alarm bird predators and the reaction of most birds, especially in the young, is to take flight. The response is more powerful when it is a watching face; a pair of eyes is more frightening to them than a single eye-shaped form and one can experiment with this: watch with your hand over one eye and the birds might be untroubled. Remove it and they will flee. Deep in their adaptive minds is the knowledge that predators have their eyes in the front of their heads, giving them the necessary, wide, binocular gaze, and it is that double, watching, hungry vision that birds fear and avoid.

We bring terror in our wake. Charles Foster, the English writer on the wildness of animals, has said that whenever he wanders into the section of a bookshop called “Birdwatching,” he looks for those books that might describe or try to describe the experience of birds watching us.

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What do they make of us? What is that large mammal that likes to stop on its walk through the wood and somehow transform its little eyes into a pair of bug-eyed predatory lenses with which it tracks us as we pass?

Could we ever trust it? What is its world, its intention? What does it want?

I have come to think that the inaccessibility of birds is the heart of their marvelousness. Both concealment and their capacity for distance and height is their form of pride. We do not own them. They possess themselves, even as their indifference makes us long for them. “You don’t hear birds, you hear worlds,” Olivier Messiaen, the great French composer, once wrote. That unknowable otherness, the way in which they represent the complex, involved presence of entire life systems that are not-us but are somehow interleaved with our own, is the source of the birds’ beauty. They are unknowability itself alive in front of us, colored, feathered, voluble, quick, inaccessible, with something fractal about them, so that the more you look, the less you know. Or perhaps the more you look, the more you know how little you know. You can only be led toward them, as if into a mystery.

Excerpted from Bird School: A Beginner in the Wood by Adam Nicolson. Published by Farrar, Straus and Giroux, September 2025. Copyright © 2025 by Adam Nicolson. All rights reserved.

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Lead image: A raven. Credit: Piotr Krzeslak / Shutterstock

Adam Nicolson

Posted on September 10, 2025

Adam Nicolson is the author of many books on history, landscape, and great literature. He is the winner of the Somerset Maugham Award, the W. H. Heinemann Award, and the Ondaatje Prize. His books include The Life Between the Tides and Why Homer Matters. He lives on a farm in Sussex.

Physics

- The Two-Body Problem for Women in Science

- How to Measure the Universe

PHYSICS | VIEW ON WEBSITE

The Two-Body Problem for Women in Science

Can bends in spacetime accommodate a career in physics and a family?

By Shohini Ghose    September 4, 2025

It’s quite distracting to fall in love while studying physics. I speak from experience. I’m not talking about an esoteric passion for equations or a metaphorical obsession with nature’s laws (although I’ve experienced those, too). I’m talking about real, dizzying, wonderful, human romance. The kind that makes you want to throw your physics books away (almost) and sing songs about birds chirping and flowers blooming while walking hand in hand.

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Luckily for my career, he was a fellow graduate student in physics, and ours was a romance filled with debates about quantum physics, as we skipped classes and ignored research projects in favor of bike rides and nature hikes, concerts and movies. Spacetime had obviously warped to bring us together. On the eve of the new millennium, we resolved to greet the 21st century as partners for life.

Our wedding was a joyous and nerdy affair, celebrated by our two families as well as our common physics family of fellow students, staff, and faculty. The wedding invitations included quotes from physicists, and many bad physics jokes were shared and hooted down at the reception. In our very own “Gift of the Physics Magi” moment, our thesis supervisors asked us what gift we would like to mark the occasion. I requested a beautiful bound copy of Feynman’s Lectures in Physics for my fiancé, not knowing that he had done the same for me.

As we settled into married life, my Ph.D. research in the nascent field of quantum information science progressed rapidly. I was very lucky to be working in a new area where every question I explored yielded exciting results (something that is rather unusual in most other physics research fields). I particularly enjoyed studying quantum entanglement—nature’s peculiar version of bonding between microscopic particles. Somehow, I could relate to the connection between the entangled pairs I was studying.

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Before I knew it, three years zoomed by, and I successfully completed and defended my dissertation. I was offered a dream postdoctoral research position, but it would require moving over 9,000 miles away from my partner. Spacetime was warping the other way and pulling us apart.

I was far from the first woman to have to choose between career and family. But in our case, there was the added wrinkle that both of us were seeking academic careers in physics, which severely limited our options. This challenge is common enough in the academic world that it has its own nickname borrowed from a well-known problem in physics—the “two-body problem.”

History is filled with women who faced similar dilemmas, and more often than not, physics lost.

Take the case of Harriet Brooks—Canada’s first woman nuclear physicist. Within a span of six years between 1898 and 1904, Brooks discovered the element radon, measured its half-life, kickstarted the understanding of radioactive transmutation of elements, discovered the radioactive recoil effect, and pointed out the multiple stages of radioactive decay. Along the way, she had become the first woman to obtain a graduate degree at McGill University, and the first woman to work with two future Nobel Prize winners. She had proved her skills at three renowned academic institutions, and she had published a paper on her own in Nature.

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I was far from the first woman to have to choose between career and family.

Yet she had to abandon her faculty position at Barnard College after announcing her engagement. Barnard, founded in 1889 in response to Columbia University’s policy of not admitting women students, insisted that she resign. Her advisor, the Nobel Laureate Ernest Rutherford, recognized her brilliance, describing her as another Marie Curie, but it wasn’t enough to save her career.

Harriet Brooks is not the only woman that physics has lost to the gender variable.

Lucy Mensing, who performed groundbreaking research in the emerging field of quantum mechanics, ended her physics career in 1930 after the birth of her first son. In Australia, Ruby Payne Scott blazed a trail in radio astronomy and later chose to start a family, but without any option for maternity leave, she gave up her career.

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In England, Muriel Barker graduated from Cambridge in 1915 (although as a woman she did not officially receive a Cambridge degree). She then continued her graduate studies in aeronautics at Cambridge. In 1922, she published new insights about the velocity of wind flowing through a narrow bar, but the same year, she hit the “marriage bar”—a common policy in the United Kingdom that prevented married women from continuing to work.

Who knows how many more women disappeared from the physics universe? All over the world, the marriage bar swept through the ranks of women scientists, removing every trace of them from the scientific record.

I often hear the claim that physics is an objective science in which there is no room for discussions about gender and identity. After all, the equations used in physics are gender neutral. In Newton’s famous equation F = ma, the variable F stands for force, not female. And yet this objective field is full of very subjective human bias. Harriet Brooks’ gender certainly mattered in the choices she was faced with. There was no middle ground for her. It was physics or family. Physics was the worse for it.

Over the years, her decision led to her name fading from the historical record. Friedrich Dorn got the credit for the discovery of radon (in reality, his paper said little about its nature, while it was Brooks and Rutherford who first identified it as a new gas). Of Marie Curie and Harriet Brooks, history remembers only Curie.

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As for my own choice of physics versus family, I was no Curie-like exception. Choosing to follow my research dreams to Australia meant putting physics ahead of family, and I could not do that. On the other hand, I refused to yield to the marriage bar. Crucially, I did have one thing in common with Curie—a supportive partner. The two of us made a pact, our personal solution to the two-body problem. We would face the marriage bar equally. We would never put our individual academic careers ahead of our joint personal lives. So, Australia was out.

A few years later, an equally attractive research opportunity arose for my partner in Europe. That too was nixed. We knew, of course, that our solution to the two-body problem could not work forever. The real solution would be for academic institutions to accommodate couples with new “marriage support” policies rather than “marriage bar” policies. But almost no such policies exist, even today.

Eventually, our meandering career paths and valiant efforts to balance family and academics came to a head. We never did find a dual solution to the two-body problem. We were forced to face the marriage bar. I embarked on an academic career as a freshly minted physics professor. My partner chose to leave physics.

I often wonder what I would say to Harriet Brooks if I had the privilege of meeting her. I would have a thousand questions for her, of course, but what would I tell her about me? I would want to describe my physics research, I’m sure. But I would also very much want her to meet the man who curved spacetime for me. He carved himself a new niche in the continuum in a sparkling new career, and he found a way to fit us both in. And he never looked back. He and Harriet would have a lot to talk about.

This excerpt is reprinted with permission from MIT Press Reader. It is adapted from Her Space, Her Time.

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Lead image: mnaufal design / Shutterstock

Shohini Ghose

Posted on September 4, 2025

Shohini Ghose is a professor of physics and computer science at Wilfrid Laurier University, Canada. She is the director of the Laurier Centre for Women in Science (WinS) and the NSERC Chair for Women in Science and Engineering. She is the author of Her Space, Her Time.

PHYSICS | VIEW ON WEBSITE

How to Measure the Universe

What units can unexpectedly reveal about fundamental puzzles in physics

By Sabine Hossenfelder    September 4, 2025

Units span the gap between math and reality, between platonic ideals and physical quantities. But what are units? I think it’s one of the most underrated questions in the foundations of physics.

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We use them to measure and study everything from distance to numbers of particles to luminous intensity. In the International System of Units—the established standards for scientific measurements—there are seven types of units: second, meter, kilogram, ampere, kelvin, mole, and candela. Any other units are products of those, such as meters per second squared makes a unit of acceleration. Or kilogram times meter over second square, that’s a unit of energy.

All of that said, we don’t actually need all those seven units. In fact, I hope to convince you that we don’t need units at all.

Take the latter four units: ampere, kelvin, mole, and candela. They are actually related to the first three by constants of nature.

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For example, ampere is the flow of charge per second, and if you know the elementary charge, you can define ampere from a velocity times that elementary charge times the number of electrons which has no unit. Kelvin is a temperature, but it’s proportional to energy with the factor being a constant, so it’s really just a convention we even use it. The mole is fixed by Avogadro’s number, and so on.

I hope to convince you that we don’t need units at all.

So this leaves us with seconds, meters, and kilograms—measures for time, length, and mass. We can now express the units of any quantity as a product of those, relying on some exponents and some constants.

This is where things start to get interesting. Because, as the theoretical physicist Max Planck figured out at the end of the 19th century, all those units that we normally use are really just human baggage. Meters, seconds, teaspoons, gallons per mile, minutes per pint, that’s all politics.

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Planck said, there’s one, and only one, way to make units of length, time, and mass from fundamental constants. And those are the “natural” units that describe our universe. In his 1899 paper presenting the idea, he called them “Natural Measurement Units.” The idea was that measurement systems ought to be guided by the universe itself, rather than, say, the weight of an arbitrary volume of water in France. (I’m looking at you, kilogram—originally defined in the 18th century as the weight of a liter of water.)

The fundamental constants, then that you construct are the speed of light (that’s c), Planck’s constant (that’s called hbar), and Newton’s constant (that is the strength of gravity, usually denoted capital G).

Planck said, look, you can combine those three constants to give a mass, a length, and a time, now called the Planck-mass, -length, and -time respectively. And there you have it, units of measurement that align with the workings of the universe itself. No French Revolutionary-era scales required.

You wouldn’t use Planck units in everyday life, though, because they’re rather impractical. We would have to drag around ridiculous exponents of numbers to the -40 or so just to give the weather forecast.

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Or I should say, you wouldn’t use them in everyday life unless you’re a physicist. But if you were, these are the units you want to work with if you talk about, say, the Big Bang. Or what goes on inside of black holes. Or quantum gravity, and those sorts of things. Because out there, beyond the reaches of country borders and our outer atmosphere, things like kilograms and seconds stop making quite so much sense. For example, the spacetime curvature at which the quantum effects of gravity become strong is 1 in units of the inverse Planck length square. That might sound complicated, but if you try to do that calculation in the International System of Units, I promise you, it will be a lot messier.

Here’s another reason I think this existential units question (which you may otherwise brush off as overly esoteric) is so important: Looking more closely, Planck units reveal something very interesting about quantum gravity.

You can ask for example, what’s the mass that a particle must have so that the quantum uncertainty on the size is below the Schwarzschild radius, the radius at which an object of a given mass will collapse to a black hole, if compressed below it. If that could happen, then the combination of quantum physics and conventional non-quantum physics stops making sense. So this gives you an estimate for when quantum gravity becomes relevant. (This is easy to estimate. Let’s call the mass m. The quantum uncertainty on the size is then Δx = hbar divided by (m times c) Now we want to know when is Δx equal to the Schwarzschild radius related to the mass, which is G times m divided by c square. Insert m, and we can solve for Δx, which is the square root of G hbar divided by c cube. And that is exactly Planck’s length!)

Measurement systems ought to be guided by the universe itself.

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What this means is that a particle with such a mass would also be … a black hole. It sits at the intersection of gravity and quantum physics. We have never measured a particle with such a mass, but they’ve been hypothesized. They’re called Planckions. Some people think that if black holes evaporate, they stop at this size and they leave behind these particles—and those could make up dark matter. I digress, but you see that the question of units is intimately tied into the very foundations of contemporary physics.

So, practical or not, Planck units have a fundamental relevance because they’re unambiguous. Anyone everywhere who can make measurements can infer them. (Again, you can leave your H_2O, measuring cups, and scales at home.) This is why Planck said if there is intelligent life out there, these are the units they’d use—and that we should use them in our communication, too.

What can we learn from this seemingly very academic exercise? There are a couple things I find fascinating about this.

The first is that the Planck units are no longer unique. Planck couldn’t have known this, but we now also have the cosmological constant. And you can construct natural units by using the cosmological constant, c, and hbar instead. I think this is an indication that we are actually missing a relation between the cosmological constant and Newton’s constant.

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Another thing I find interesting is the structure that is behind the three units and the fundamental constants they are built up from.

You see, the speed of light converts time to length. A year is a time, a light-year is a length. The speed of light also converts energy to momentum. You can then take the inverse of time and length and use Planck’s constant to convert that to energy and momentum respectively. What this means is that the speed of light is a map from time to space and back. And Planck’s constant is a map from spacetime to momentum-space and back.

But then when we introduce Newton’s constant into the equation, we get even wilder things. For example, a time that would give us cubic meters per kilogram per second. This isn’t a unit that we use. Why not? The reason is that Newton’s constant is related to gravity, and for gravity we don’t deal with energy and momentum. We deal with energy density and momentum flux and curvature. Those are defined not as a total, but per volume. They’re densities. And Newton’s constant, divided by the fourth power of c converts spacetime curvature to these densities. This is what appears in Einstein’s equations.

This tells us that we have a disconnect between this spacetime-momentum space picture that we use in quantum physics and the curvature-density picture that we use in general relativity. I think it’s one of the reasons why we’re having trouble squaring quantum physics with gravity. You see, it’s all well and fine to say that a particle with some energy doesn’t have a definite position, as quantum mechanics proposes. But it makes no sense to say that an energy density doesn’t have a position, because the density is a function of the position.

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It might seem like a minor point, but I hope I have convinced you that units are not just here to help us count and measure the things around us—but that by looking within them we may be able to solve some of the biggest questions in physics today.

For more from the author, check out her YouTube channel.

Lead image: Evannovostro / Shutterstock

Sabine Hossenfelder

Posted on September 4, 2025

Sabine Hossenfelder is a theoretical physicist at the Munich Center for Mathematical Philosophy, in Germany, focusing on modifications of general relativity, phenomenological quantum gravity, and the foundations of quantum mechanics. She is the creative director of the YouTube channel “Science without the gobbledygook” where she talks about recent scientific developments and debunks hype. Her latest book is Existential Physics: A Scientist’s Guide to Life’s Biggest Questions. Follow her on X (formerly known as Twitter) @skdh.

Psychology

- Does Musical Taste Narrow with Age?

- Can I Give You Some Advice?

- When Your Father Is a Magician, What Do You Believe?

- Here’s Why Binge-Watching Is Good for You

- Why This 17-Year-Old Girl Can’t Forget

PSYCHOLOGY | VIEW ON WEBSITE

Does Musical Taste Narrow with Age?

What 450 million song plays tell us about how our listening habits evolve

By Bob Grant    September 12, 2025

As our own personal timelines shorten, so too does our list of favorite tunes. At least, that’s what a group of researchers in Europe suggest. The scientists propose that as we transition into adulthood, the world of music opens up, and we seek out new genres, artists, and styles. But as we continue to age, our listening habits narrow, our explorations tending to be more informed by our personal histories.

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“When you’re young, you want to experience everything,” co-author Alan Said, computer scientist at the University of Gothenburg in Sweden, noted in a statement. “You don’t go to a music festival just to listen to one particular band, but when you become an adult, you’ve usually found a style of music that you identify with.”

Said and his colleagues arrived at this conclusion after analyzing data from more than 40,000 users of last.fm, a platform that allows listeners to share their musical tastes as curated by streaming services like Spotify. Crucially, when someone registers on last.fm, they can enter their age, giving the researchers a way to connect listening habits to age. For the study, the team considered 15 years worth of data that captured more than 540 million plays of more than 1 million distinct songs.

The researchers found that younger listeners tended to seek out diverse musical inputs, but as people grew into middle age and beyond, they became more beholden to a narrower band of music, often with nostalgia as a central refrain in their listening. While older folks continued to seek out new musical experiences to some degree, they frequently returned to the musical styles that defined their youth. “Most 65-year-olds don’t embark on a musical exploration journey,” Said added. The scientists presented their findings at an international computer science conference in June and recently posted a version of the paper, which is not yet peer reviewed, on the pre-publication site ArXiv.

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The trends that Said and his co-authors reported may help fine tune and customize recommendation algorithms that suggest music to listeners on popular streaming platforms, such as Spotify or YouTube Music.

The study is also a welcome reminder that there is a virtually boundless universe of music out there, more accessible to contemporary humans than at any point in history. That makes for unprecedented opportunities to challenge these proclivities and discover a new and exciting song, no matter your age.

Lead image: KurArt / Shutterstock

Bob Grant

Posted on September 12, 2025

Bob Grant is the deputy editor at Nautilus.

PSYCHOLOGY | VIEW ON WEBSITE

Can I Give You Some Advice?

Probably not

By Charles Digges    September 12, 2025

I’d tell you not to read this article, but you’d probably ignore me and simply decide for yourself.  Even if I listed some well-founded reasons to dissuade you—shouldn’t you really be doing something else? Aren’t you driving right now?—you’re likely to disregard it and press ahead.

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You wouldn’t be alone. As it turns out, most of us tend to blow off even good advice and decide most questions for ourselves.

These findings come from a sweeping new study led by University of Waterloo psychologist Igor Grossmann, that suggests our instinct to politely nod along to the advice we hear and then carry on with our own judgment isn’t just a personal quirk. It’s something we all do.

Involving more than 3,500 adults across a dozen countries, the research Grossmann and his collaborators conducted shows that when people—from big, technologically advanced cities to humble Amazonian villages—face tough decisions, they are far more likely to rely on their own intuition or reasoning than to take guidance from friends, family, or experts. Even in interdependent cultures that prize group harmony, self-reliance proved more durable than the advice of others. For better or worse, it’s our own counsel that we trust most.

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The majority preferred to shoulder the burden themselves.

“Realizing that most of us instinctively ‘go it alone’ helps explain why we often ignore good counsel, be it for health tips or financial planning, despite mounting evidence that such counsel may help us make wiser decisions,” Grossman told me over email.

To examine this, Grossmann and an international team of collaborators set up a simple experimental questionnaire asking participants to envision tricky dilemmas. A team of anthropologists, linguists, and psychologists helped adjust the questions so they were relevant to the society where they were being asked. For instance, where the participants led agricultural lifestyles, they were asked how they would invest a windfall, buying an orchard or a herd of cattle. Other more urban socio-economic groups were asked how they would decide which university to attend or where they would choose as a travel destination.

The researchers also probed decisions that would involve making choices that might disadvantage the one doing the choosing—whether to help a neighbor with their farm before the rainy season sets in, which might put tending to your own harvest in jeopardy, or whether to help an academically struggling friend during your own study time. The respondents were equally male and female and ranged in age from 20 to 40 with educational levels ranging from primary school through graduate degrees.

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Participants were then asked which of four strategies they would use to make their decisions. Would they deliberate privately? Follow intuition? Seek advice from friends or family? Turn to the wisdom of their larger group by, say, throwing the question to social media? By giving subjects a menu of possible strategies, the researchers could see which approaches felt most natural. Participants were also asked to evaluate how good they felt about their own selections.

What emerged was a striking consistency. Across cultures, ages, and social backgrounds, self-reliant strategies—deliberating alone or trusting intuition—topped the list. Seeking advice came in a distant second. In fact, only about one in 10 participants reported that consulting others would be their primary approach to handling a tough decision. The majority preferred to shoulder the burden themselves—and they felt good about it to boot.

We expect others to make their choices differently than we do.

There were some slight divergences when it came to what sort of dilemma was being considered, Grossmann told me.

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“People were more likely to discount others’ perspectives when it came to decisions involving social dilemmas—helping a friend or protecting one’s own interests—as compared to a choice between equally attractive options, for instance, which university to go to,” he wrote me. “But even in the latter case, people still favored self-reliant decision strategies.”

And while the preference for self-reliance remained general across all cultures, Grossmann told me that the strength of that preference depends on where one comes from. Culture “controls the volume knob, dialing up that inner voice in highly independent societies and softening it somewhat in more interdependent ones,” he wrote.

Advice For Thee, But Not For Me

What’s ironic is that we expect others to make their choices differently than we do. When respondents were asked to guess what other people in their society would do when presented with the various test dilemmas, they expected other folks to take a friend’s advice just as often as they expected them to deliberate in solitude. In other words, our own thinking is important to us, but other people perhaps need a little more guidance—advice for thee, but not for me.

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According to neurobiologist Robert Sapolsky, who was not involved with the study, this sort of egocentrism regarding our own thinking is central to why self-reliance makes more sense to us in our decision-making.

“When comparing the conclusions you reach on your own compared to those offered by experts, you know what your internal process was in getting to that decision and can never know theirs,” he told me. As Sapolsky pointed out to me, the heat of the moment is when we’re most likely to default to self-reliance. “This is another manifestation of the tendency to make a bad decision during stress,” he said.

This points to an interesting problem: The moments when advice might help us most—whether it’s about our money, or our careers, or perhaps the emergence of a once-in-a-generation public health emergency—seem to be the ones where we’re least likely to take it.

“What we see is that in the context of difficult decisions, people prefer to deliberate on how to decide about the choices by themselves even if it goes against what others may recommend them,” Grossmann told me. “And that is indeed problematic, because psychological distance, as stimulated by considering views of others, can be a really great way to see the big picture of the issues at hand, especially in the heat of the moment.”

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So, is there really any point in offering advice? Grossmann says yes. But his study proposes that we need to think hard about how advice is framed and delivered. “Now, here are some other things you may consider based on what others thought about it, too … Something like this, perhaps?”

But, hey. If, against my early advice, you’ve read this far, well done. Sometimes keeping your own counsel really is best.

Lead image: Anton Vierietin / Shutterstock

Charles Digges

Posted on September 12, 2025

Charles Digges is an environmental journalist who edits the website of the Norwegian environmental group Bellona.

PSYCHOLOGY | VIEW ON WEBSITE

When Your Father Is a Magician, What Do You Believe?

A childhood spent under the spell of sleight-of-hand taught me skepticism, curiosity, and the habit of looking beneath appearances

By Richard E. Cytowic    September 9, 2025

My earliest lessons in observation came not from a laboratory but in the living room, with my father in his tuxedo and top hat. To everyone else, he was “Big Ed,” a larger-than-life physician who was a magician, an archer, a raconteur, and much else. By day, he mesmerized patients with his easy confidence; by night, he dazzled guests with sleight-of-hand, conjuring coins from behind ears or producing endless scarves from his sleeve. To me, he was both healer and illusionist, a scientist and showman.

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When your father is a magician, what do you believe? As a child, the boundary between real and unreal was porous. I wanted to believe in the rabbit pulled from a hat, the floating light bulb, the miraculous escapes. But even as a boy, I began to notice the seams: the telltale flash of a hidden card, the tiny bulge in his sleeve where the coin waited. What others applauded as mystery became for me a problem waiting to be solved.

Magic had taught me that the improbable might still have an explanation.

It was not cynicism so much as curiosity that drove me. I learned that every illusion, no matter how beguiling, had a mechanism beneath it. Magic was an invitation to look closer, to ask: How does this really work?

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That question—posed again and again in my childhood—propelled my apprenticeship in science. I became my father’s assistant, carrying props, rehearsing patter, acting as the straight man. But I was also his skeptic. If a trick fooled me, I made it my job to discover how. When he succeeded, I applauded; when I found the secret, I felt the satisfaction of uncovering a law of nature.

From illusion I learned skepticism, and from skepticism, a demand for evidence. It was not enough for something to merely look true. I wanted to know the actuality that lay underneath.

That questioning attitude extended beyond the stage. Growing up in the 1950s, the world outside our house was already steeped in performance: Cold War drills at school, cocktail parties where adults wore masks of cheer while anxieties ran deep, a culture addicted to appearances. My father, a physician in the golden age of tranquilizers, was the embodiment of contradictions—capable of genuine healing but also of grandiose self-invention.

BIG ED: The author’s father was affectionately known as Big Ed. By day he was a physician, beloved among his patients. By night, he was a magician who dazzled guests with sleight-of-hand. Photo courtesy of Richard E. Cytowic.

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It was in this crucible of illusion and reality that I began to form my own identity, not only as a son but as a budding scientist. If magic depended on deception, then science seemed the greater magic still, because it depended on asking the right questions and letting evidence answer.

By the time I reached adolescence, I had begun my own crude “experiments.” I timed how long a match would burn in different conditions, weighed the contents of my chemistry set before and after reactions, charted the night sky from our New Jersey backyard. None of this was formal science, but it carried the same spirit as pulling apart my father’s tricks: looking beneath appearances, testing hunches, insisting that truth is not what dazzles but what endures.

The deeper I went, the more I saw parallels between magic and the mind. A magician misdirects attention; so too does the brain. A conjurer exploits expectation; so does perception. Illusion, whether on stage or in the cortex, depends on our willingness to fill in the gaps, to accept appearances at face value.

Later, as a neurologist, I would return to these early lessons when studying synesthesia and the quirks of perception. Patients told me that numbers and letters had colors, or that tastes evoked shapes. For decades, science dismissed reports like these as fantasy. But I had been raised to treat appearances with suspicion and testimony with care. The boy who once peered into his father’s sleeves to see what was hidden became the man who listened attentively and openly when patients described hidden worlds of perception.

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Magic had taught me that the improbable might still have an explanation—if only one was willing to look hard enough.

And so I came to believe that the real wonder is not in the disappearing coin or the vanishing dove. The real wonder is in the human mind that constructs reality from fragments, that can be fooled by a flourish, but that can also be illuminated by experiment. My father taught me to vanish before I learned to appear. Science taught me to appear without vanishing—to stand by evidence, to let truth emerge even when it contradicted the spectacle.

To this day, when I step into a lecture hall or clinic, I carry both inheritances: the magician’s sense of wonder and the scientist’s demand for proof. If illusion taught me skepticism, science gave me faith—not in appearances, but in inquiry itself.

What is broken can be made whole, and what seems impossible can be understood. That is the greatest trick I ever learned, and it has nothing to do with rabbits or hats.

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This excerpt is reprinted with permission from MIT Press Reader. It is adapted from The Magician’s Accomplice: My Father and I in the Age of Anxiety.”

Lead image: fran_kie / Shutterstock

Richard E. Cytowic

Posted on September 9, 2025

Richard E. Cytowic is a professor of neurology at George Washington University. He is the author of several books published by the MIT Press, including Synesthesia: A Union of the Senses, The Man Who Tasted Shapes, The Neurological Side of Neuropsychology, Your Stone Age Brain in the Screen Age. He recently published a memoir The Magician’s Accomplice: My Father and I in the Age of Anxiety.

PSYCHOLOGY | VIEW ON WEBSITE

Here’s Why Binge-Watching Is Good for You

Rabidly consuming TV shows, movies, or books could make us more imaginative and able to cope with stress

By Bob Grant    September 5, 2025

We’ve all been there. We think to ourselves, Let’s just watch one more episode, or I’ll read one more chapter before turning off the light. The next thing you know, the clock reads 3:30 a.m., and you’ve traded valuable REM sleep for an overabundance of entertainment. Then the guilt sets in.

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But a study from researchers at the University of Georgia suggests that binge-watching and -reading could actually be good for us. Engaging in bouts of marathon media consumption, they suggest in a paper published in Acta Psychologica, can make a person better able to remember what they consumed and “might help people recover from daily stressors through retrospective imagination.”

Their thinking goes like this: The longer someone imbibes stories in a single setting, the more deeply and longer their minds are engaged with them, even after the viewing or reading session ends. Even more so than for folks partaking of shorter, scheduled bursts of entertainment, the binger’s imagination is fired to the point that they fantasize about the characters, plot, and other story elements long after the screen is turned off or the book is closed.

Researchers had previously coined the phrase retrospective imaginative involvement to describe the act of intensely engaging with a narrative after the experience is over, using one’s imagination to mentally reconstruct the events and interact with the characters and plot. It turns out we already knew that this kind of imaginative exercise can have a couple of benefits, such as restoring depleted mental resources and coping with stressors. Earlier, researchers had also detailed the benefits of binge watching—including greater autonomy, relatedness, and psychological well-being. But it was unclear how the two phenomena were connected: whether the positive outcomes of bingeing on TV shows, movies, or books, were specifically due to the benefits of imaginatively engaging with the narrative after the fact, and whether bingeing or scheduled narrative consumption were greater drivers of that imaginative afterglow.

So the researchers surveyed about 300 undergraduate students at two midwestern universities, asking them about their media consumption habits and how they remained more or less involved with specific stories when they were not watching or reading about them.

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They found a strong relationship between consecutive media consumption and the tendency for those binged stories to linger longer in the consciousness. Not only were binged stories more memorable among survey respondents, they were more likely to trigger extended imaginative involvement than stories consumed in a scheduled, periodic way.

“People who have that habit of binge-watching shows often aren’t doing it passively but are actually actively thinking about it afterward,” Joshua Baldwin, lead author of the study and postdoctoral researcher at the University of Georgia, said in a statement. “They’re very much wanting to engage with stories, even when they’re not around to watch shows.”

This, they suggest, could mean that bingeing TV shows or books could trigger even more of the restorative functions of extended imaginative involvement than waiting a week for the next episode to air or reading one chapter each night before succumbing to slumber.

Baldwin and his coauthors admit that the study had several limitations. For one, the survey was retrospective, asking participants to remember shows they’d watched or books they’d read. This means that the scientists couldn’t capture how stories affected thinking while they were in the midst of watching or reading them, reducing the accuracy of the data they culled from the recalled memories. Also, the study population was small and, being from midwestern universities, not necessarily representative of broad swaths of humanity. Finally, the study was conducted during the COVID-19 pandemic, when binge-watching became a way of life among the quarantined masses. “Our participants were likely to have the option to consume narratives more often and for longer amounts of time than they would normally,” they wrote in the paper. Tell me about it.

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Even with these caveats, this study provides a ray of hope to the bingers among us. Perhaps these results can defray some of the crippling guilt and stigma associated with basking in the glow of that screen a little too long or laying awake and reading well past one’s bedtime.

Lead image: HilaryDesign / Shutterstock

Bob Grant

Posted on September 5, 2025

Bob Grant is the deputy editor at Nautilus.

PSYCHOLOGY | VIEW ON WEBSITE

Why This 17-Year-Old Girl Can’t Forget

Some people have extraordinary powers of mental time travel

By Kristen French    September 3, 2025

My memory has ruled my life,” a singular 34-year-old woman told some researchers a couple of decades ago as they sat chatting in their University of California, Irvine, lab. Known as the human calendar to her friends but nicknamed AJ in later research reports, the woman had written to them in distress. She was looking for help. “I want to know why I remember everything,” she said. AJ told the scientists that she couldn’t turn her memory off, even when she was engaged in other activities that demanded her attention, like talking to a friend. “It’s like a running movie that never stops.”

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Previous cases of superior memory had generally involved an individual’s ability to remember and rattle off long lists of meaningless information, such as words or digits, as opposed to personal recollections. So the team of scientists ran AJ through a battery of tests. They found that she was indeed able to effortlessly reel off the details of clear and verifiable memories for numerous dates and that her scores were off the charts on standardized and informal autobiographical memory tasks.

The scientists reported on AJ’s condition, and coined the term “hyperthymesia” to describe it, in Neurocase in 2006. Since that time, researchers have documented at least 100 cases of hyperthymesia in the literature. Almost uniformly, those who have the condition find the memories—which tend to be carefully indexed by date—intrusive, uncontrollable, and distressing.

Which is why the recently published case study of a 17-year-old girl dubbed TL is commanding attention. Like others with hyperthymesia, TL has an exceptionally intense and vivid memory for the events that have occurred over her short life. She can provide an especially rich amount of perceptual, spatial, and temporal information, and even recall events from multiple points of view. But unlike the others, she is able to organize these memories into a kind of “memory palace,” and can access them whenever she likes. Most of the memories, she says, are filed in “binders,” according to theme and date and stored in a place she calls “the white room.”

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Other rooms in her palace include a “pack ice” room, which she uses to cope with anger; a “problems” room, where she can reflect on challenging situations; and a “military” room, which appeared when her father joined the army. For the most part, she does not find recalling her personal past in this way upsetting. Scientists from the Paris Brain Institute and Paris Cité University recently published an account of TL’s unique condition in the journal Neurocase.

The French scientists tested not only TL’s ability to remember the past but her ability to imagine the future and found she excelled at both. They hypothesized that her ability to control her memories about the past, and to cope with how readily available those memories are, may be at least partially related to her ability to so vividly imagine the future—to time travel. Even for average folks, autobiographical memory is generally associated with a type of consciousness known as “autonoetic,” which not only allows us to relive past events but project ourselves into imaginary situations.

Some studies suggest that hyperthymesia may involve an overactivation of brain networks involved in autobiographical memory and in certain visual tasks. But so far, scientists have not identified any neuroanatomical differences between hyperthymesics and individuals with normal memory. Hyperthymesia may also be linked to synesthesia, said Laurent Cohen, neurologist and co-head of the PICNIC Lab at the Paris Brain Institute who co-authored the case study, in a statement. TL does not have synesthesia, a neurological condition in which sensory processing often involves at least two senses at once—people hear colors or taste sounds—but many of her family members do.

Cohen and her colleague Valentina La Corte, a research professor at the Memory, Brain, and Cognition Laboratory at Paris Cité University, who assessed TL together, have many remaining questions: Does aging affect the memories of hyperthymesics? Can people like AJ or TL learn to control their accumulations of memories? “Everything remains to be discovered,” said La Corte.

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Lead image: Jorm Sangsorn / Shutterstock

Kristen French

Posted on September 3, 2025

Kristen French is an associate editor at Nautilus.

Zoology

- We Owe It All to Figs

- Shark Teeth Are Crumbling

- Where Will the Sloths Go?

- These Carnivorous Bats Are Softies

- Wild Jaguars Caught in the Act

- Putting Humans First Is Not Natural

ZOOLOGY | VIEW ON WEBSITE

We Owe It All to Figs

Our primate ancestors’ love of the complex fruit changed the world

By Rob Dunn    September 15, 2025

Ripe apples drop about my head . . . The nectarine and curious peach Into my hands themselves do reach.

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—Andrew Marvell, “The Garden”

When you bite into an apple, a pear, or a peach, you bite into the result of thousands of years of interactions between these fruits and primates. When you let a fig squish in your mouth, you are savoring an even more ancient story. These moments of pleasure are reenactments of a kind of jungle theater that has played out again and again for tens of millions of years. But it didn’t start this way.

Before the fruit, in a beginning, all of the seeds that dangled from trees fell from those trees. These were gravity’s seeds. They might be pushed this way or that by the wind or fall into the river and drift along shores, but that was all for their travels. Most fell below their mother tree. In her shade, they died. Mother plants sometimes smother. This was long the fate of plant progeny. Some trees evolved seeds with wings, that they might be carried a little farther, but only when the winds willed.

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Then, some plants evolved fruits. Fruits were a radical evolutionary innovation; they surrounded seeds and attracted animals in order that those animals might consume them and ingest their seeds. They called out, “Eat me.” This was their proclamation made in the form of bold colors, scents, and even flavors. Some of the seeds were ground up by the teeth of those animals. Others died in their guts. A few survived. Each bit of feces deposited by a fruit‑eating bird or mammal was pregnant with the potential of a forest.

A forest can walk across a landscape in the gut of a primate, traveling one defecation at a time.

Then came our kind, not the first humans, not yet, but instead the first of our extended family, the first primates. They evolved in the tropics, around 60 million years ago, in the shadow of the extinction of the dinosaurs. Those first primates have been hypothesized to have consumed the fruits of trees as well as flowers, and then, also, insects attracted to fruits and flowers. Over the succeeding tens of millions of years, some of the descendants of those first primates became more dependent on fruits. Meanwhile, many trees grew increasingly dependent on those fruit‑eating primates for dispersal of their seeds; this was a relationship of mutual benefit and dependency. The primates lived in the trees the way that the protist Mixotricha paradoxa lives inside a termite, or the way that cilia-like spirochetes live on the protist. Conversely, like the spirochetes living on the protist, the primates helped the trees to move. Metaphorically, a forest can walk across a landscape inside the gut of a primate, traveling one defecation at a time.

It is likely that our shared ancestor with all other apes, a kind of ur-ape, ate leaves, bark, and insects, but especially fruit. So, too, for our much more recent ancestor, the most recent common ancestor of chimpanzees and humans. Paleoanthropologists refer to this species, which lived 5.5 to 7.5 million years ago, as the Chimpanzee‑Human Last Common Ancestor, or CHLCA; for ease, let’s call them chilcas.

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In broad strokes, the diets of chilcas were likely similar to those of chimpanzees. The primatologist Christophe Boesch began studying chimpanzees in the Taï National Park in Côte d’Ivoire in the 1970s. He studied those Taï chimpanzees in detail, but then also went on, with a large team, to study chimpanzees across Africa. Through this larger project, called “The Cultured Chimpanzee,” Boesch and his colleagues, collaborators, and mentees have demonstrated that chimpanzee cultures, and hence diets, vary from one community to the next.

Many but not all chimpanzee communities use sticks to eat ants. Others use sticks to eat termites. Many use sticks to access honey. Some use sticks to kill and eat bush babies. Bush babies are small, big-eyed, nocturnal primates with adorable little hands that look, yes, like furry babies living up and among the trees. Some chimpanzees love to eat them. Other chimpanzee populations use sticks to gather and eat algae.

Others hunt colobus monkeys. Chimpanzee diets are varied. Yet The Cultured Chimpanzee collective found that, despite this variation, chimpanzee populations share a dependence on fruit. More than anything theirs is a diet of fruit, and especially figs. Red figs. Green figs. Plump purple figs. Small figs and enormous figs. Chimpanzees include figs in 80 percent of their daily meals during the long fig season. An average daily chimpanzee diet often includes hundreds of individual figs.

Chilcas and other ancient fruit‑eating primates gardened their own worlds.

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Figs were also a key fruit of the ancient garden planted by chilcas. And it was a garden. Ancient chilcas ate figs and deposited their seeds. Those seeds grew, eventually, into trees. The more figs the chilcas ate, the more fig trees they planted, until the forests they lived in abounded (as they still do today) with figs. The fig trees also supported the insects and colobus monkeys that, if they were like chimpanzees, the chilcas might have also eaten.

By gardening fig trees and other tree species with delicious fruits, chilcas and other ancient fruit‑eating primates gardened their own worlds. Scholars, depending on their field, sometimes call this “world-making,” “niche construction,” or “ecosystem engineering,” analogies drawn from literature, art, and engineering, respectively. This “making” is passive on behalf of the primates. They don’t actively choose to make forests. But as I’ll discuss, many of the other steps humans took in partnering with other species weren’t necessarily active either.

In general, where primates are more abundant, so, too, are the fruit trees whose fruits they like to eat. Primates grow their own forests by “planting” the seeds of their preferred fruits; they can even create new forests when they move into the open habitats at the edge of the tree line. When primates become rare, so, often, do the fruit trees that depend upon them. When giant lemurs went extinct in Madagascar, the large‑fruited species that depended upon them became rarer. You can’t have arboreal primates without their trees, and, in some cases, you can’t have the trees without the primates.

Both primates and trees also have other mutualistic partners. Primates depend not only on fruits, but also, just like termites, on their gut microbes. It is these gut microbes that convert the fiber in figs into energy. Chilcas, we can infer, depended upon their gut microbes to help them digest their food. They depended on their microbes to help defend them against pathogens. Such microbes helped to keep them alive, and so one might say that they also help to keep the figs around. When one species (one of the chilcas’ gut microbes) affects another species (say, a fig species) via its effect on an intermediate species (the chilcas), ecologists describe these effects as “indirect.” The living world is full of Rube Goldberg-like indirect effects that, though sublime, are hard to study, and harder to describe.

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As for the figs, they often depend on other seed dispersers such as bats and birds. They depend on fungi that connect to their roots and give them access to the nutrients in deeper, smaller interstices in soil and rock (in exchange for sugar or fat). And they depend on wasps that pollinate their flowers. It is these wasps, called agaonids, or fig wasps, that know the subtlest arts of fig making. Nearly all species of figs are pollinated by these tiny wasps. Fig wasps and fig trees appeared to have evolved simultaneously some 85 million years ago. They evolved in relation to each other. As fig trees have diverged, so too their wasps.

They also evolved to be dependent on one another. This dependence is very particular and relates to the details of fig flowers. Fig flowers dwell inside a spherical structure called a syconium (plural, syconia), from the Greek, sykē (συκῆ), for “fig.” The word is thought to derive from a connection to Sykeus, one of the few Titans to survive the war against the Olympian gods. After the war, Zeus continued to pursue Sykeus. Sykeus fled to the bosom of his mother, the Earth goddess, Gaia. For his own protection, Gaia turned Sykeus into a fig tree draped with Earth-shaped syconia, now named in his honor.

Nature can be, at once, red in tooth and claw and collaborative.

The details of fig pollination vary depending upon the fig and wasp species. Some fig species have separate male and female syconia; in others, the syconia are all hermaphrodites. Some fig wasps accidentally disperse pollen; others do so with an active care. In all cases, each syconium contains tens to hundreds of flowers that have the potential to collectively bear seed.

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The syconium and its flower-world are entered by way of a small hole, termed the ostiole, exactly the width of a tiny pregnant female wasp—or, rather, a wasp minus its wings, which the wasp may shed upon entering, never to fly again. Once in the syconium, the female wasp pollinates some flowers. She lays her eggs in others of the flowers. She then dies, inside the fig. Her eggs become larvae, then adults, all while still inside their flowers, which by then have become a kind of botanical crèche that the plant makes in response to the wasps’ presence. The wingless adult males emerge first and mate with the winged females while they are still in their swaddling. As the now‑pregnant female wasps emerge, they become coated in pollen from new male flowers within the syconium. They then crawl out of the syconium through holes that the males dig, holes wide enough to accommodate the female wasps and their wings; this is the males’ last useful act. The exiting females then carry the fig pollen with them as they go on to look for their own forever homes.

When a chimpanzee bites into a fig, it bites into this complex biology. The same is true when you bite into a wild fig. Parenthetically, I have had the chance to work with Hjalmar Kühl and Mimi Arandjelovic, now leading The Cultured Chimpanzee project, to use samples of chimpanzee feces to decode new mysteries of chimpanzee lives. We have found that we can see the biology of figs, fig wasps, and chimpanzees excrementally. Chimpanzee feces contain the DNA of figs, fig wasps, and the parasites that attack fig wasps. This DNA is evidence that the chimpanzees eat not only the remains of baby wasps but also the bodies of the male wasps and the mother wasps, both of which die in the fig. The bodies of the wasps are protein rich, though, and so fig fruits are quick to metabolize them and turn their nitrogen and phosphorus into added resources in the fig. The figs, as a result, are more nutritious than they would be without their wasps.

As for fig wasps that don’t pollinate enough flowers, they suffer. Fig trees retaliate against such freeloaders. They drop their unpollinated syconia with the mother and baby wasps inside; the fallen fruits rot. The wasps die. Charles Darwin and Lynn Margulis were both right: Nature can be, at once, red in tooth and claw and collaborative.

At some point, maybe in the time of chilcas, or maybe a little later, our ancestors left the trees to live more on the ground. Some 4.5 million years ago, in what is now Ethiopia, fossils indicate the presence of a human relative named Ardipithecus ramidus, shortened to “Ardi.” Ardi had hands that were not as adapted to climbing as those of chimpanzees. Ardi’s legs and feet, meanwhile, were slightly better adapted to walking than those of chimpanzees. Ardi might have been one of our ancestors, or simply a relative alive alongside our ancestors. Regardless, once our ancestors did begin to spend more time on the ground, they would have faced the same tradeoffs Ardi faced. They almost certainly still ate fruits, but, like Tantalus, they would have struggled more to reach them. The figs on the highest branches would have become a sweetness just beyond reach.

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Excerpted from the book The Call of the Honeyguide by Rob Dunn. Copyright © 2025 Available from Basic Books, a division of Hachette Book Group Inc., New York, NY, USA. All rights reserved.

Lead image: Erich Karnberger / Shutterstock

Rob Dunn

Posted on September 15, 2025

Rob Dunn is an evolutionary biologist at the North Carolina State University where he studies species we interact with every day but tend to overlook—including those that live in our belly buttons. He is the author of several books, including Every Living Thing, The Man Who Touched His Own Heart, and The Call of the Honeyguide.

ZOOLOGY | VIEW ON WEBSITE

Shark Teeth Are Crumbling

As ocean acidity grows, it’s eating into their gnashers

By Sara Kiley Watson    September 11, 2025

Shark teeth are a marvel of evolution. They are so sharp that many island cultures once used them as weapons and tools to hunt and cut up meat. Unlike human teeth, shark teeth line the mouths of these ocean predators by the dozen, up to 50 rows deep. Baby sharks are born with complete sets so that they can begin hunting from a young age. But these gnashers may be no match for ocean acidity: As climate change gives marine pH a kick, some shark teeth are crumbling.

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That’s according to new research published this week in Frontiers in Marine Science. The ocean absorbs around 30 percent of the globe’s carbon emissions, which sets off a chemical reaction—when carbon dioxide dissolves in seawater, it becomes carbonic acid which leaves more hydrogen ions in the sea, lowering the pH.

“Sharks already face overfishing, pollution, and warming seas,” says Maximilian Baum, a biologist at Heinrich Heine University Düsseldorf and the lead author of the study. “If acidification also compromises their teeth, it could reduce their feeding success and overall resilience.”

Since the beginning of the Industrial Revolution in the mid 18th century, the average acidity of seawater has jumped an estimated 30 percent, with an especially dramatic change between the 1980s and now. Some experts predict that ocean acidity will double or triple by 2100 unless we drastically cut carbon emissions.

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The crumbling teeth are just one more way that climate change is messing with sharks.

This spells a nightmare for sea life, including sharks. Baum first started wondering if increasing ocean acidity could hurt shark teeth after reading a 2019 study demonstrating how their skin denticles are impacted. “That led me to wonder whether oral teeth, especially in species with constant seawater exposure, might show similar vulnerability, because shark teeth are a homologous structure to skin denticles,” he says.

For the study, Baum collected naturally shed teeth from aquarium-housed blacktip reef sharks and incubated these samples in seawater with different pH levels. He and the research team then analyzed structural changes using imaging and morphological measurements. The teeth exposed to water that was more acidic were clearly more damaged, demonstrating cracks and holes, increased root corrosion, and structural degradation. These findings could apply to other species as well—especially impacting sharks like hammerheads, tigersharks, and bullsharks that swim around with their mouths wide open, a form of passive breathing, Baum adds.

The crumbling teeth are just one more way that climate change is messing with sharks, making their home less hospitable. Warming oceans make it harder for shark eggs and juveniles to survive, increase shark metabolism—making it more energy intensive to just swim around—and disrupt their migratory patterns and the ecosystems they rely on. More extreme seasonal variations in weather and storms also complicate shark migration patterns and ability to raise their young. Nevermind that fishing pressure has already led to a 71 percent decrease in populations of oceanic sharks and rays since the 1970s.

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The main limitation of the team’s study is that they didn’t look directly at living sharks—which may be able to remineralize and replace damaged teeth to avoid the worst of the impacts, but there’s the risk that the energy cost of doing so would be high, said Sebastian Fraune, another study author and professor of zoology at Heinrich Heine University Düsseldorf, in a press release.

Having fewer sharks around is a huge problem for the ocean—as apex predators, they help to regulate the populations of other creatures in their ecosystems. In one example, a decrease in sharks in the Caribbean led to overpopulation of grouper, which then triggered a decline of the parrotfish populations that are responsible for grazing algae from coral reefs—leaving behind too much algae that now blanket some reefs. Another study demonstrated how the loss of sharks off the coast of North Carolina cascaded into a complete scallop fishery collapse. Not to mention, like whales, sharks act as massive carbon sinks when they die and fall to the ocean floor.

“Even highly evolved top predators are not immune to human caused ocean changes,” says Baum. “If their teeth are at risk, it shows how deep environmental stress can reach within marine ecosystems. It influences almost everything from the smallest shell to the biggest predator.”

Lead image: GIOVANNI NITTI / Shutterstock

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Sara Kiley Watson

Posted on September 11, 2025

Sara Kiley Watson is a climate and science journalist currently based in the Netherlands.

ZOOLOGY | VIEW ON WEBSITE

Where Will the Sloths Go?

Their habitat is disappearing as humans encroach

By Liz Lindqwister    September 10, 2025    Photo by Emmanuel Tardy

A brown-throated three-toed sloth strikes a familiar pose, clinging onto a fencepost as it slowly, very slowly, traverses the grasslands and forests of Costa Rica. Photographer Emmanuel Tardy said he watched the mammal cross the road and waited for a crowd of people to disperse before capturing this shot. The image starkly depicts the challenges sloths face as humans increasingly encroach on their habitat.

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All five species of  three-toed sloths are well known for their lethargy, moving an average of 125 feet on a given day. In spite of their perceived slowness and awkwardness, scientists note that sloths are remarkably adapted to survive in arboreal habitats. Their protruding, inches-long claws help them tightly grasp onto branches and trunks, and sloths expend very little energy daily, meaning they’re content to survive on a simple, low-calorie diet of leaves scavenged from the canopy.

Three-toed sloths move an average of 125 feet on a given day.

Yet the sloth’s reliance upon arboreal habitats is likely the underlying cause for their population decline across Costa Rica and South America, according to ongoing studies. As development creeps into natural spaces and humans introduce infrastructure like the fences shown above, sloths suffer. Ill-adapted to living on land, sloths are especially vulnerable to predators if removed from their arboreal niche and are unable to traverse across landscapes without the aid of continuous forest canopy.

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The latter factor is particularly important to sloth reproduction—and by extension, their species’ genetic diversity and survival. Highly specialized, sedentary creatures like three-toed sloths struggle to navigate landscapes without adequate trees, isolating them from possible mates and limiting their access to breeding areas. Already, rescue nonprofits in Costa Rica report higher levels of birth defects among orphaned baby sloths, and subsequent research indicates that the cause may be inbreeding in urban areas where sloths can’t move beyond narrow pockets of forest cover.

As trees continue to vanish, the sloths are left with nowhere to go.

This photograph won a commendation from the 2025 Wildlife Photographer of the Year competition.

Liz Lindqwister

Posted on September 10, 2025

Liz Lindqwister is a writer originally from Peoria, Illinois. Her reporting on tech, culture, and history has appeared in the San Francisco Standard, STANFORD Magazine, the Library of Congress, and Vox’s Today Explained. A historian by training, Lindqwister holds degrees in early American studies from Stanford University and Cambridge University.

ZOOLOGY | VIEW ON WEBSITE

These Carnivorous Bats Are Softies

They are fond of cuddle balls and rear their children for years

By Sara Kiley Watson    September 10, 2025

One of the largest and most formidable hunters in the world of bats also appears to be one of the cuddliest. Spectral bats—whose scientific name is worthy of a horror movie: Vampyrum spectrum—have wingspans of up to three feet, and for dinner they tend to gobble down birds, rodents, and even some other mammal species, including other bats. But at home with the family, they are fond of cuddling, wrapping wings and limbs around each other, as well as sharing food, and they invest heavily in child rearing.

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When Marisa Tietge, a research assistant and doctoral student at the Leibniz Institute for Evolution and Biodiversity Science in Germany, stumbled upon a cozy roost of four spectral bats in Costa Rica, she knew she had to take a closer look. The species is quite shy and difficult to find, making these bats tough to research.

“I didn’t really have any expectations,” she says. “This is a blank sheet of paper—everything that we now record is new.”

Spectral bats are special for many reasons—their inclination to hunt for their food, their monogamous mating style, and the way that they live in small families that include both the male and female parents and their offspring. This is pretty different from social behavior in most other bats, which often involves one male defending a territory with several female companions. (Only 16 out of the 84 species of bats whose mating patterns have been studied form monogamous pairs.)

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“These apex predators have such soft and gentle behaviors, and they’re so social.”

“I think one typical picture that people have about bats is like these big clusters of bats hanging together in a cave or in a group—like 50 bats or maybe hundreds or thousands of bats,” Tietge says. “This is often the case, but then in this species, it’s not the case.”

Tietge repeated visits to the roost to accustom the bats to her smell and presence. Eventually, the bats didn’t even disperse or fluster at all when she approached with her headlight. The next step was to set up motion-sensed wildlife cameras in the hollowed-out tree that the bat family called home. Her analyses of the video footage were recently published in PlosOne.

What she discovered was a picture of domestic bliss—videos demonstrated that the bats would often groom each other and often even greeted their family members with vocalizations and a hug-like action, wrapping their wings around the other’s body, when they returned to the roost after hunting or exploring. At night while they slept, the creatures formed what Tietge dubbed a “cuddle ball”: a four-way hug that included wing wrapping and touching snouts. The two baby bats were of different ages and stayed with their parents for up to two years—a long childhood compared to other bat species.

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Another fascinating behavior Tietge captured is the sharing of food. A parent would often come in, bearing a small rat or bird to eat, and essentially transfer that food to their offspring, helping ease the transition from milk to meat. Spectral bats may be big in terms of bats, but the prey they hunt is still quite large in comparison, so it’s a learning process to latch onto food while also keeping their wings open so they can eat, says Tietge. These meals can take 30 to 40 minutes.

This wasn’t the only moment of food-related cooperation. When the female parent was still weaning a pup, her partner would come back to the roost bearing gifts of prey to keep the mom’s nutrition up while she was taking care of the baby. In fact, on some occasions, when the bats brought back food to eat, the other bats already knew the intended consumer for that tasty tidbit, says Tietge. Instead of swarming the incoming bat for a bite of delicious prey, the creatures understood the context of that snack and whether or not it was intended for them, kind of like a label on yogurt in the office fridge or the name on an UberEats order.

There are several reasons why spectral bats may have such strong and cooperative relationships with their families, which Tietge credits to their role in the ecosystem. While many bats are foragers, the spectral bats are hunters which requires an entirely different set of skills and often a longer learning process. The cozy, cooperative relationship within the family gives pups time and support to learn the complex set of skills that they need to survive and succeed in their unique circumstances.

“I think it’s so cool and fascinating that these apex predators have such soft and gentle behaviors, and they’re so social,” Tietge adds. “I hope this kind of shows to people that bats aren’t mysterious, dangerous creatures. There’s a lot that we can relate to, and there’s even parallels to our own behavior.”

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Lead image: Marisa Tietge, CC-BY 4.0

Sara Kiley Watson

Posted on September 10, 2025

Sara Kiley Watson is a climate and science journalist currently based in the Netherlands.

ZOOLOGY | VIEW ON WEBSITE

Wild Jaguars Caught in the Act

The first clip of a black jaguar mating in the wild could inform conservation efforts

By Molly Glick    September 4, 2025

In a feisty first, a black jaguar was recorded mating in the wild. This NSFW clip was captured at Serra do Pardo National Park in the Brazilian Amazon.

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It’s tricky to document jaguars outside of captivity because they’re highly elusive and solitary predators. But during an expedition to track biodiversity in understudied areas of the Brazilian Amazon, researchers captured this six-minute video clip of the two cryptic cats. Their findings were recently reported in the journal Ecology and Evolution.

“We hit the proverbial jackpot,” said study author Carlos Peres, a conservation biologist at the University of East Anglia, in a statement. “If they’d moved a few meters we would have missed everything!”

CAT COURTSHIP: This still is from a clip of a never-before-seen sexual encounter that offers helpful hints into elusive jaguar behavior. Credit: UEA / YouTube.

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When studying the clip, the researchers investigated how two key aspects might influence jaguar mating: coat color and wild versus captive settings. The female’s dark coat, which results from a genetic mutation, may also influence mating behaviors or fertility. (Dark coats like this one tend to be more prevalent in humid environments like the Amazon and affect some 10 percent of jaguars worldwide.) The video also helps answer questions of whether jaguars living in the wild mate differently than their counterparts in captivity, where jaguars typically have low reproductive success.

Overall, the recorded encounter suggests that jaguar courtship seen in captivity is similar to the rituals that occur deep in the jungle, and that the female’s black coat didn’t appear to influence the interaction. The specifics of this clip, along with future research, could help guide matchmaking and the timing of artificial insemination in captive breeding programs.

The team might have also spotted the female jaguar playing a reproductive trick previously documented in jaguars and other big cats—she seemed to exhibit certain signs of lactation, including swollen nipples, suggesting she wasn’t actually fertile at the time.

This clever cat may have harnessed the “hide-and-flirt” strategy: Male jaguars sometimes kill non-related cubs in order to mate with their mothers, so the females with recent litters may hide their offspring and mate with courting males to confuse them regarding their own paternity status. Mating outside of ovulation could also serve to “deplete the sperm reserves of males, thereby reducing fertilization success in rival females,” according to the paper.

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This romantic revelation is just the tip of the iceberg. Researchers still don’t have a firm grasp of the behavior of most Amazonian species in the wild. But filming these jaguars at just the right moment provides a non-invasive peek into their mysterious private lives.

Watch the video here.

Lead image: Adrian Dockerty / Shutterstock

Molly Glick

Posted on September 4, 2025

Molly Glick is the newsletter editor of Nautilus.

ZOOLOGY | VIEW ON WEBSITE

Putting Humans First Is Not Natural

Christine Webb on her 3 greatest revelations while writing The Arrogant Ape

By Christine Webb    September 3, 2025

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The most dangerous myths are the ones we don’t see. Human exceptionalism—the belief that humans are fundamentally separate from and superior to the rest of nature—is one of those myths. It’s embedded in religious doctrine, textbooks, political campaigns, advertising, and everyday language. This worldview is not hidden because it’s obscure—it’s hidden because it’s everywhere, taken for granted, and rarely named or questioned. That’s precisely where its power lies. I think human exceptionalism is the most powerful unspoken belief of our time.

But what struck me most in writing The Arrogant Ape was just how thoroughly this belief has infiltrated science—an institution meant to challenge our biases, not reinforce them.

In my field of primatology, for instance, we routinely compare the intelligence of captive chimpanzees—raised in highly restricted, human-made environments—with that of fully autonomous Western humans. And then we conclude that humans are cognitively superior. But that’s not a fair comparison. Imagine testing a child raised in isolation and concluding they have no empathy or desire to cooperate. When we observe our closest living relatives in richer socioecological contexts, we witness striking prosocial behavior.

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When we measure the world with a ruler made for humans, other species inevitably come up short.

Or take research on self-awareness. For decades, we believed only humans and a few other primate species could recognize themselves in mirrors, a supposed benchmark of self-awareness. But the mirror test is biased toward vision. Dogs experience the world primarily via scent. They pass an olfactory mirror test with ease—demonstrating self-awareness in their dominant sensory modality.

When we measure the world with a ruler made for humans, other species inevitably come up short.

Yet we persist in treating the human brain as the blueprint for intelligence and consciousness. We assume that minds are special only insofar as they resemble our minds; that there is a hierarchy of mindedness, with us standing comfortably at the apex. Evolutionary diagrams tend to reinforce this view, depicting a neat, linear trajectory: bacteria, plants, worms, fishes, rats, dogs, monkeys … all the way up to us. Even our taxonomic name—Primates, from Primata, meaning “of the first rank”—betrays the same assumption.

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This isn’t just bad evolutionary thinking—it’s a profound failure of imagination. And its consequences are far-reaching. Human exceptionalism supports the belief that the Earth exists solely for human benefit, reducing other species to mere resources. This mindset rationalizes exploitation not just of other animals and ecosystems, but also of other human beings who are deemed “sub-human.” But when we expose and challenge this myth, we don’t just unsettle our assumptions—we open the door to better science and deeper relationships with the rest of the living world.

Many people treat human exceptionalism as a natural conclusion. But recent studies in developmental and cross-cultural psychology suggest otherwise. Beliefs in human exceptionalism aren’t an inevitable outcome of our biology—they instead reflect a cultural worldview, one largely shaped and codified by dominant Western traditions.

When researchers presented American children and adults with moral dilemmas—such as saving one human or multiple animals—adults overwhelmingly favored humans, even when the trade-off involved 100 dogs or pigs. Children didn’t. They often chose to save multiple animals over one human, valuing human and nonhuman lives far more similarly. This pattern has now been replicated in multiple European countries. In such Western contexts, children are also far more likely than adults to judge it wrong to harm animals for food, and less likely to ignore information about the minds of animals typically considered food.

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These findings suggest that the anthropocentric moral frameworks commonly held by adults are not the biological default. They emerge over time through cultural learning—particularly as children become increasingly exposed to the ways other forms of life are used and valued in our society.

Children often chose to save multiple animals over one human.

Research across human cultures also reveals that human exceptionalism is far from a universal view. Many Indigenous and non-Western knowledge systems reject such natural hierarchies. They recognize other animals, plants, rivers, forests, and mountains as kin: sentient, agentive beings embedded in a shared moral and ecological world. Far from immature or naïve, these are sophisticated cosmologies grounded in millennia of observation, relationship, and reciprocity with the living world. Within these frameworks, the notion that humans are separate or superior simply doesn’t hold.

Writing The Arrogant Ape introduced me to various alternative cosmologies and traditions that reject the ideology of human exceptionalism. These worldviews don’t simply critique the ideology—they model ways of living in greater balance with the rest of the natural world (as just one example, studies reveal that Indigenous-managed lands often have equal or higher biodiversity than formally protected areas). Encountering these alternative relationships exposed the narrowness of my own upbringing and education. And it made me aware of the cultural and historical forces—especially colonialism and capitalism—that helped globalize the myth of human exceptionalism under the guise of progress and science.

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If we see ourselves as separate from nature, we treat the Earth not as a community we belong to, but as a set of resources to extract, manage, or “fix.” Recognizing this changed how I think about the ecological crisis. It’s easy to blame global warming on fossil fuels, industrial excess, or political inaction. But we don’t just need to reform these institutions—we need a new relationship with the living world, and a different story about who we are within it.

Some today maintain that humans are the most evolutionarily “successful” species. Success, in this view, is measured by ecological dominance—our capacity to spread across the globe while manipulating and controlling our environments. But in reality, the most resilient ecosystems—and the most sustainable ways of living—are not built on domination, but on interdependence. What if cooperation were the faculty by which evolutionary “success” was measured and achieved? In ecology, cooperation and mutualism are just as prevalent and essential to life as competition and predation. Yet recent research shows that more than two-thirds of the publications in the journal Ecology study “competition,” while less than 2 percent investigate “cooperation.” We’ve constructed our scientific models around struggle and individualism, even though life on earth is held together by relationships and co-evolution.

The COVID-19 pandemic laid bare the dangers of this worldview. It likely emerged, in part, because of human encroachment into wild habitats. And yet, media narratives celebrated human ingenuity in vaccine development while ignoring the systemic exploitation that made the outbreak possible. Militarized language—the “war” or “battle” against the virus—cast nature as the enemy to be conquered and destroyed once again. Similar thinking surfaces in climate discussions, where technofixes like solar geoengineering or colonizing Mars promise salvation through further domination.

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These fixes rely on the same logic of control: that we can outmaneuver the planet’s limits instead of learning to live within them. They assure us that humanity will prevail after all, but they echo the very mindset that brought us to the brink in the first place! We are not above nature—we are expressions of it. Our bodies, minds, and cultures evolved in deep entanglement with the earth over millions of years. To imagine ourselves as exempt from ecological constraints is not foresight; it’s delusion. This is not to say that technical innovations have no role in addressing climate change. But I think some of them are best understood as new—and arguably more powerful—forms of human exceptionalism.

We often conflate dominance with success, mastery with genuine understanding. But real insight comes from humility—acknowledging what we don’t know, listening to others (including other species), and recognizing the limits of our conventional frameworks. Writing The Arrogant Ape was humbling in the best sense. It taught me that seeing ourselves clearly—not as rulers, but as participants in a larger web—is one of the most urgent scientific and moral challenges of our time.

Lead image: captures_by_ap / Shutterstock

Christine Webb

Posted on September 3, 2025

Christine Webb is an assistant professor in the Department of Environmental Studies at New York University, where she is part of the animal studies program. She is a broadly trained primatologist with expertise in social behavior, cognition, and emotion. She works with nonhuman primates in diverse settings and collaborates with scholars from the social sciences and humanities to reimagine the role of science in the growing charge to grant moral status to other animals. Her work has been covered by popular outlets including The New York Times, The Washington Post, National Geographic, and the BBC.

Table of Contents

Nautilus: 2025 Sep 15

Astronomy

Meet the Asteroids Next Door

Communication

Scientists Are People, Too

Environment

Rogue Wave Mystery Solved

You Can Help NASA Track Hurricane Damage

This Forest Survived a Megafire

Cities Obey the Laws of Living Things

Evolution

When Nature Burst Into Vivid Color

Health

Our Dark, Unvaccinated Future

History

DNA’s Death Notice

These Early Humans Walked 8 Miles for the Perfect Rock

Philosophy

Why I Became a Birdwatcher

Physics

The Two-Body Problem for Women in Science

How to Measure the Universe

Psychology

Does Musical Taste Narrow with Age?

Can I Give You Some Advice?

When Your Father Is a Magician, What Do You Believe?

Here’s Why Binge-Watching Is Good for You

Why This 17-Year-Old Girl Can’t Forget

Zoology

We Owe It All to Figs

Shark Teeth Are Crumbling

Where Will the Sloths Go?

These Carnivorous Bats Are Softies

Wild Jaguars Caught in the Act

Putting Humans First Is Not Natural