By Claire L. Evans It was the dead of winter in Boston. The surface of the Charles River was frozen solid. But Zachary Kelso (opens a new tab) braved the biting cold to finally put to rest a mystery that has haunted neuroscience labs for over half a century. To do that, Kelso, a research assistant in the Harvard lab of the neuroscientist Sam Gershman (opens a new tab), needed some worms. Specifically, planarians: arrow-headed flatworms, which are among the simplest creatures to possess a brain and a nervous system with bilateral symmetry like ours. Normally, labs order these widely used model organisms from biological supply companies. But the mail-order worms weren’t up to snuff. So Gershman had dispatched Kelso to the Charles’ icy banks to catch some wild ones. “I thought, ‘I’m going to look crazy because I’m using a hammer to beat through the ice,’” Kelso recalled. “So I wore the more business end of business casual.” In philosophy, “qualia” refers to the subjective qualities of our experience: what it’s like for Alice to see blue or for Bob to feel delighted. Qualia are “the ways things seem to us,” as the late philosopher Daniel Dennett put it. In these essays, our columnists follow their curiosity, and explore important but not necessarily answerable scientific questions. It wouldn’t be the last time Kelso found himself in this situation. The Charles River planarians, it turned out, didn’t cut it either. Neither did the worms he sourced while stream-hopping around Eugene, Oregon, in March 2025. Nor did the ones he fished from Michigan lakes that June — this time in thigh-high waders — while picnicking families gawked from shore. Kelso diligently turned over rocks, angled with bits of meat tied to a string, and even followed maps from a vintage guidebook called The Fresh-Water Triclads of Michigan (opens a new tab). But his adventure was fruitless. Sure, he caught plenty of planarians. But back in Gershman’s lab, none of them would do what they were supposed to do. (C) Simons Foundation

Keyword: Learning & Memory; Evolution
Link ID: 30272 - Posted: 06.06.2026

By Erin Garcia de Jesús Buff-tailed bumblebees can figure out on their own how to use a ball as a ladder to nab sugar from an out-of-reach fake flower, researchers report in the June 4 Science. The insects worked out the trick without specific training for the solution, suggesting a remarkable capacity for solving problems. Bumblebees are brainy, with studies showing they may have emotions and can teach one another to score goals in a six-legged version of soccer. The new finding adds yet another skill to their repertoire. “Spontaneous problem-solving is something that has never been shown in any invertebrate before,” says Olli Loukola, a behavioral ecologist at the University of Oulu in Finland. Vertebrates including chimpanzees and parrots can problem solve on their own, although researchers typically focus on captive animals with plenty of experience working out puzzles. “Our study is the first one where we can be 100 percent sure that these individuals don’t have any prior experience about any problem-solving tasks,” Loukola says. Loukola and colleagues first taught bees two necessary associations: Balls are moveable objects and a blue ring — representing a flower — means food. The team then let the bees loose in plexiglass arenas too small for them to fly to reach a blue ring printed on the ceiling. © Society for Science & the Public 2000–2026.

Keyword: Learning & Memory; Intelligence
Link ID: 30271 - Posted: 06.06.2026

By Sara Novak Whether tucked away in a colony of coral, hidden in the darkness of an aquatic cave or floating catatonic just above the ocean floor, fish take opportunities for rest and recovery, just as we do. Like humans, most fish are diurnal, meaning they sleep mostly at night; while they don’t have eyelids, and therefore can’t shut out the darkness, light does disrupt their sleep. And just like us, when they snooze they’re motionless and slow to respond to environmental stimuli. If you deprive them of sleep, they will make up for the loss by sleeping longer the next night. Now, a new study, released this month in Nature Communications, shows just how much fish sleep really does resemble our own. By tracking eye movements of zebrafish, the researchers were able to identify four different substates of sleep, akin to the “stages” of sleep that scientists have described in humans. “There’s complexity to their sleep structure,” said Jennifer Mengbo Li, a co-author of the study and a neuroscientist at the Max Planck Institute for Biological Cybernetics in Germany. Three of the four substates happen at night, lasting a total of 10 hours. The first — and deepest — is characterized by a stone-cold stare. As the waking hours near, a second, lighter substate sets in: The zebrafish’s eyes twitch, sideways in the same direction, before moving slowly back to center. In the third substate, entered as morning approaches, both eyes turn to the same side and stay there. During the fourth and final substate, which takes place in brief bursts during the day, the zebrafish’s eyes move back and forth, as if sweeping the surroundings for potential risks. But the eyes can be deceiving: These five-to-10-minute naps are deep enough that much of the brain activity is suppressed, and the zebrafish are hard to wake up. © 2026 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 30263 - Posted: 05.30.2026

By Yasemin Saplakoglu When an optometrist shines a bright light into your eyes, a vast, branching tree sprouts in your field of vision. This is the shadow of blood vessels. Though we normally can’t perceive them, these vessels always occlude a portion of what we see, and for an important reason. They power the retina, a thin layer of nerve tissue in the back of the eye that communicates light signals to the brain. The retina is one of the body’s most energetically expensive tissues. Built from complex networks of sometimes more than 100 different types of neurons, retinal tissue consumes two to three times more energy than the same mass of typical brain tissue. That’s why most vertebrate retinas, including our own, are furrowed with dense, branching networks of blood vessels: to deliver oxygen and other ingredients for producing energy. But there’s a significant exception to this rule. Birds have retinas that mostly lack blood vessels. This may seem especially strange given birds’ exceptional vision. The bird retina is “one of the most metabolically active tissues in the animal kingdom, yet it worked with no apparent blood perfusion,” said Christian Damsgaard (opens a new tab), an evolutionary physiologist at Aarhus University. “It was a complete paradox.” For centuries this has puzzled scientists, who figured that the bird retina must obtain oxygen through a unique, undiscovered process. Damsgaard is the lead author of a study, published in the journal Nature (opens a new tab) in January 2026, that showed for the first time that bird retinas don’t have some unusual adaptation for acquiring oxygen — they survive without it entirely. Instead, to bring energy to the tissue, they use a process called anaerobic glycolysis that is significantly less efficient than oxygen-powered metabolism but gets the job done. © 2026.Simons Foundation

Keyword: Vision; Evolution
Link ID: 30247 - Posted: 05.16.2026

By Hannah Thomasy For nearly a decade, Vincent Bombail has been tickling rats. It’s been a standard technique used in the study of animal happiness. But not all rats particularly enjoy the experience, data show. Female rats prefer gentler, more playful tickling than males, Bombail and his colleagues report April 15 in Biology Letters. The findings suggest that the same physical experience evokes a different emotional response in different individuals, potentially influencing the results of studies on animal happiness. “This research helps us understand these animals as playful but also rich and complex and having opinions,” says Daniel Weary, an animal welfare scientist at the University of British Columbia who was not involved in the study. “Understanding the affective lives of animals is actually one of the coolest and most difficult questions there is in science,” he says. As early as the 1930s, researchers deliberately exposed rats to standardized negative experiences to study the physical effects of stress. Figuring out how to study positive experiences took longer. It wasn’t until the 1990s that researchers developed the standard tickling protocol, where a researcher flips a rat over, pins it on its back and tickles its belly. The protocol is intended to mimic the rough-and-tumble play of young male rats. © Society for Science & the Public 2000–2026.

Keyword: Emotions; Evolution
Link ID: 30242 - Posted: 05.16.2026

Liam Drew Three hearts; blue blood; no skeleton; arms like tongues. These are just some of the alien features of octopuses, squid and cuttlefish — members of the cephalopod family. The outlandish list continues. Cephalopod skin can taste chemicals, sense light and change colour and texture rapidly. In many species, the sucker-covered arms can even regenerate. These invertebrates have evolved independently from the vertebrate lineage for more than 600 million years. Their last common ancestor was probably a worm-like creature with a rudimentary nervous system and eye-like patches of light-sensitive cells. Despite this evolutionary gulf, vertebrates and these highly specialized molluscs share strange similarities. Their eyes, for example. “It’s eerie how similar they ended up,” says Cristopher Niell, a neuroscientist at the University of Oregon in Eugene. “The convergent evolution of the eye still blows my mind.” Now, one similarity is spurring a boom in cephalopod neuroscience. Around 400 million years ago, cuttlefish, squid and octopuses diverged from the only other living cephalopods — the nautiluses. They then lost their protective shells and evolved brains that are uniquely large among invertebrates. These brains bestow the soft-bodied cephalopods with high intelligence. Cuttlefish, squid and octopuses have excellent memories, use tools and are adept problem-solvers; they have a concept of time and are capable of delayed gratification. Cephalopods are the only non-vertebrate animals that have big, smart brains, says Cliff Ragsdale, a comparative neuroscientist at the University of Chicago in Illinois. And that presents a unique opportunity. Neuroscientists have gained a wealth of knowledge about how vertebrate brains work, but are increasingly looking to cephalopods for insights into ways to build large, high-functioning nervous systems. © 2026 Springer Nature Limited

Keyword: Evolution; Intelligence
Link ID: 30231 - Posted: 05.02.2026

Nicola Davis Science correspondent It has long been known that dogs have less between their ears than wolves, but now research has suggested their brains started to get smaller at least 5,000 years ago. Experts say the results offer fresh insights into the domestication of our canine companions. However, the findings are unlikely to explain why your spaniel will only drink from a muddy puddle: the researchers say a reduction in brain size does not mean dogs are dafter than their wolf-like ancestors. “The way our dogs live nowadays doesn’t give them the opportunity to always express most of their intelligence,” said Dr Thomas Cucchi, first author of the study from the French National Centre for Scientific Research. “But they are extremely clever and domestication didn’t make them stupid, but made them really capable of reading us and communicating with us.” The relationship between humans and canines is ancient, with research revealing the oldest direct genetic evidence for domestic dogs dates back more than 15,000 years. But while a reduction in brain size is typically considered a hallmark of domestication, there has long been debate over exactly when dogs ended up with smaller brains than wolves, with some experts suggesting this may have occurred early in the dog-human relationship. However, others argue smaller brain size is not a hallmark of domestication but instead reflects the emergence of pedigree breeds in the last 200 years. Writing in the journal Royal Society Open Science, Cucchi and colleagues studied CT scans of the skulls of 22 prehistoric wolves and dogs, dating from 35,000 to 5,000 years ago, as well as CT scans from the skulls of 59 modern wolves and 104 modern dogs. The latter included different modern breeds as well as stray or “village” dogs, and dingoes. © 2026 Guardian News & Media Limited

Keyword: Evolution
Link ID: 30220 - Posted: 04.29.2026

By Jake Currie Chimpanzees and humans share 98 percent of their genomes, so what’s in that 2 percent that makes us uniquely human? According to a new study published in Science Advances, a tiny portion of these genes play an outsized role in our language skills—and Neanderthals had the same sequences. Subscribe to skip ads Featured Video These segments of the human genome, known as Human Ancestor Quickly Evolved Regions (HAQERs) are non-coding sequences that showed accelerated evolution after humans split from the ancestor they shared with apes. Even though they represent only 0.1 percent of our genes, they’re responsible for the neural “hardware” for language. “What we’re seeing is how a very small part of the genome can have an outsized influence, not just on who we were as a species, but on who we are as individuals,” study author Jacob Michaelson of the University of Iowa said in a statement. “These aren’t genes we’re talking about. They’re regulatory regions that act like the volume knob on genes.” The HAQERs also interact with another vital speech gene: FOXP2. Identified in 1998, FOXP2 is a transcription factor active in the development of the neural circuitry of language use, and mutations in the gene can cause speech problems. “So, if the HAQERs are like volume knobs that can be turned, FOXP2 is one of the hands that is turning these volume knobs,” Michaelson said. © Nautilus 2026

Keyword: Language; Evolution
Link ID: 30215 - Posted: 04.26.2026

Hannah Critchlow About 2 billion years ago, evolution performed an improbable experiment. A larger ancestral cell engulfed a smaller bacterium. It should have been a meal. Instead, it became a merger. The bacterium survived inside its host, and together they forged one of the most consequential partnerships in the history of life. The host offered shelter and access to oxygen. The bacterium supplied something revolutionary: a vastly more efficient way to generate energy. From this intimate alliance emerged the eukaryotic cell – and with it, the possibility of complex life. Every plant, animal and thinking being traces its lineage back to that ancient symbiosis. Our capacity for reflection, imagination and doubt rests upon what was once a free-living microbe. We call these descendants mitochondria. They persist in nearly every cell of our bodies, hundreds to thousands at a time. In total, we carry an estimated 10 million billion of them – collectively accounting for roughly a 10th of our body mass. Red blood cells are the exception: they lack mitochondria, which maximises oxygen transport. Almost every other cell depends on them absolutely. Neurons are especially demanding hosts. Each contains thousands of mitochondria, occupying up to 40 per cent of its volume. These rod-shaped structures are often described as the cell’s powerhouses. Through aerobic metabolism, they generate most of the chemical energy that keeps cells alive and functioning – the molecular fuel that sustains every biological process. Although the brain represents just 2 per cent of body weight, it consumes about 20 per cent of our energy at rest. Every perception, memory, emotion and idea is metabolically expensive. Thought itself is an energy-hungry act. Weight for weight, our brains are more mitochondrial than neural. This is more than a biological curiosity. It suggests that cognition is inseparable from metabolism – that the mind is not only shaped by networks of neurons but by networks of energy. © Aeon Media Group Ltd. 2012-2026.

Keyword: Biomechanics; Evolution
Link ID: 30213 - Posted: 04.22.2026

By Bethany Brookshire It’s easy to think of the human body as a single, fully integrated unit. After all, stub your toe all the way at one end of your body, and your brain registers it at the other. A suite of muscles works together to hop up-and-down and the lungs fill with air to expel curses from your mouth. In this moment, your body is one organism, one set of cells all pulling together against the world — and whatever it was that hurt your toe. But while our cells all work together to help us walk, eat and argue with each other on the internet, they are not all pulling together toward the same goal all the time. Each one of the body’s 30 trillion to 40 trillion human cells is its own world, with its own set of DNA that accumulates its own changes over time. These mutations can mean nothing, but they can also mean everything. While many mutations are inert, others cause harm. Still others bring hope, and could correct some of the body’s problems, science writer Roxanne Khamsi explains in Beyond Inheritance. The book draws on the latest research across multiple fields of science to show that mutations are with us throughout our lives, shaping our health and our lifespans. Many people might think of mutations as things that arise and take over only in times of trouble such as cancer. Otherwise, mutation is something that matters only if it’s passed down to the next generation — whether it produces a new eye color or a serious genetic disorder. But mutations do far more than determine what we look like when we’re born and the manner in which we die, Khamsi argues. “Our genetic destinies are not necessarily defined by what we inherit from our biological parents,” she writes. © Society for Science & the Public 2000–2026.

Keyword: Development of the Brain; Genes & Behavior
Link ID: 30208 - Posted: 04.22.2026

Oliver Milman We may appear to have little in common with sperm whales – enormous, ocean-dwelling animals that last shared a common ancestor with humans more than 90 million years ago. But the whales’ vocalized communications are remarkably similar to our own, researchers have discovered. Not only do sperm whale have a form of “alphabet” and form vowels within their vocalizations but the structure of these vowels behaves in the same way as human speech, the new study has found. Sperm whales communicate in a series of short clicks called codas. Analysis of these clicks shows that the whales can differentiate vowels through the short or elongated clicks or through rising or falling tones, using patterns similar to languages such as Mandarin, Latin and Slovenian. The structure of the whales’ communication has “close parallels in the phonetics and phonology of human languages, suggesting independent evolution”, the paper, published in the Proceedings B journal, states. Sperm whale coda vocalizations are “highly complex and represent one of the closest parallels to human phonology of any analyzed animal communication system”, it added. The findings are the latest discovery about the lives of sperm whales by Project Ceti (standing for Cetacean Translation Initiative), an organization that has studied whales off the coast of Dominica in an attempt to find out what they are saying. Last month, the project released video of a sperm whale giving birth while other whales supported it. © 2026 Guardian News & Media Limited

Keyword: Animal Communication; Language
Link ID: 30201 - Posted: 04.15.2026

By Siddhant Pusdekar Deer mice, common across North America, come in two varieties: One lives in prairies, whereas the other inhabits forests. The life of the forest mouse requires greater dexterity—a skill it possesses thanks to its higher number of corticospinal tract axons, according to a January preprint. The existence of “genetically tractable subspecies of deer mice with different behavioral niches” made the discovery possible, says Eiman Azim, associate professor of molecular neurobiology at the Salk Institute for Biological Studies, who wasn’t involved in the study. It enabled the researchers to link genetically driven changes in corticospinal abundance and morphology to dexterity. The new work reveals one way dexterous skill may emerge, while also suggesting neuroscience should investigate “behaviors that evolved for the natural niches” to discover fresh insights, says Ariel Levine, a senior investigator at the U.S. National Institute of Neurological Disorders and Stroke, who wasn’t involved in the study. Dexterity in primates coevolved with direct connections between layer 5 cortical neurons and motor neurons in the spinal cord, Levine says. In rodents, cats and less dexterous monkeys, however, corticospinal neurons connect to motor neurons via interneurons. Direct cortical-motor neuron connections exist in juvenile mice, but they are pruned during development, a 2017 paper showed. Artificially stopping the pruning process created adult lab mice with greater skill at gathering food pellets.

Keyword: Evolution; Development of the Brain
Link ID: 30196 - Posted: 04.11.2026

By Erin Garcia de Jesús My early days of nursing a newborn felt like I’d transformed into a 24-hour diner. A demanding yet adorable customer flagged me down with piercing cries to demand milk around the clock. Unfortunately, I was also on clean-up duty, wiping spit-ups and poopy butts. Breastfeeding is hard work. But after reading science journalist Elizabeth Preston’s book The Creatures’ Guide to Caring, I’m glad I’m not a burying beetle. The critters use mouth and anal secretions to knead small dead animals into slick balls of meat. Parent beetles then bury the smothered carcasses and lay their eggs nearby. Some species even feed their brood regurgitated bits of carcass, helping the young beetles grow to 200 times their original size in just six days. “A newborn human growing at that rate would be the size of a beluga whale in less than a week,” Preston writes. Suddenly my own kid doesn’t seem so heavy. The Creatures’ Guide to Caring was born out of Preston’s growing fascination with the biology of parenting after having her first child. “If so many people have done it before you, and are doing it right now — if so many animals are doing it without books or apps or advice to heed — why is it the hardest thing you’ve ever done?” she writes. Perhaps by finding kinship in the animal world, Preston could learn something about her new role as a parent. Each chapter dissects the benefits and drawbacks of parenting, piecing together how it evolved in humans and other creatures. © Society for Science & the Public 2000–2026

Keyword: Sexual Behavior; Evolution
Link ID: 30191 - Posted: 04.08.2026

By Michael S. Rosenwald Robert Trivers, a visionary, eccentric and volatile evolutionary biologist who explored the genetic reasons humans cooperate, compete and deceive each other, drawing comparisons to Charles Darwin in a career filled with intellectual highs and behavioral lows, died on March 12, in Mount Vernon, N.Y. He was 83. His death, at his daughter Natasha Trivers Howard’s home, was confirmed by his family. No cause was given. Professor Trivers was a rebellious figure in academia who joined the Black Panthers, clashed with colleagues and spoke in support of the convicted sex offender Jeffrey Epstein, from whom he accepted research money. He was often stoned and nearly always armed with a knife for self-defense. “Robert Trivers was unlike any other academic I have known,” David A. Haig, an evolutionary biologist at Harvard, wrote in a remembrance of Professor Trivers for the journal Evolution and Human Behavior. “In another life, he might have been a hoodlum.” Raised by a diplomat and a poet, and educated at Phillips Academy in Andover, Mass., and Harvard University, Professor Trivers thrived on challenging scientific orthodoxies, calling the field of psychology a “set of competing guesses.” (He also scorned physics, noting that its utility was “connected primarily to warfare.”) In the early 1970s, as a graduate student at Harvard and later as an untenured professor there, he published a series of papers applying Darwin’s theory of natural selection to social behavior, arguing that science had failed to connect evolution to an understanding of everyday life. © 2026 The New York Times Company

Keyword: Evolution
Link ID: 30179 - Posted: 03.28.2026

By Marlowe Starling The passage of the sun across the sky — dawn, day, dusk, night — drives the clock of life. Some species wake with the sun and sleep with the moon. Others do the opposite, and a few keep odd hours. These naturally driven, 24-hour biological cycles are known as circadian rhythms, and they do more than cue bedtime: They regulate hormones, metabolism, DNA repair, and more. When life falls out of sync, there can be dire consequences for health, reproduction, and survival. Lacking watches, many species keep time using an internal system — a set of interacting genes and their protein products that effectively keeps track of a 24-hour period — that is calibrated by sunlight. This kind of circadian clock is widespread, found even in single-celled algae, which suggests that biological timekeeping evolved billions of years ago. Across animals, most species have the same genetic system, using genes known as CLOCK, BMAL1, and CRY, or recognizable homologues. This form of biological clock mechanism appears even in ancient lineages, including sponges and some jellyfish. But is this the only way to do it? In a pea-size jelly off the coast of Japan, biologists are examining a different kind of timekeeping. Somewhere over the course of their evolution, the class of hydrozoans — which includes certain kinds of jellyfish, hydras, and colonial siphonophores such as the Portuguese man-of-war — lost the genes that operate circadian clocks in the rest of the animal kingdom. Yet a newly discovered hydrozoan jellyfish species has a mysterious circadian clock that regularly tracks 20-hour periods, suggesting that its mechanism evolved independently. The findings, published (opens a new tab) in PLOS Biology in January 2026, push the limits of what chronobiologists consider “circadian.” © 2026 Simons Foundation

Keyword: Biological Rhythms; Evolution
Link ID: 30169 - Posted: 03.21.2026

By Phie Jacobs Talk about an odd couple. At least 100,000 years ago, a female Atlantic molly (Poecilia mexicana) living in the fresh waters near what is now Tampico, Mexico, mated with a male sailfin molly (Poecilia latipinna). The offspring of this cross-species coupling ought to have been sterile, like a mule. But this particular hybrid went on to birth a brood of daughters—all of which were genetic clones of their mother. Scientists have long assumed this reproductive strategy of birthing clones to be an evolutionary dead end among vertebrate animals, with offspring inevitably succumbing to genomic degradation over time. But the Amazon molly (Poecilia formosa), named for the fierce female warriors of Greek mythology, has kept on defying the odds. According to research published today in Nature, it all comes down to a quirk of genetics that helps reverse harmful mutations. “This is a very cool story,” says University of Oklahoma biologist Ingo Schlupp, who provided the study authors with samples but otherwise wasn’t involved in the new work. Researchers who study asexual animals, he explains, have been “scratching our heads” trying to figure out how some species manage to avoid what evolutionary theory predicts to be certain doom. Although asexual reproduction is common in bacteria and plants, it only rarely occurs in vertebrate animals. Often, these “virgin births” involve a process called parthenogenesis, in which an embryo develops from an unfertilized egg cell—no contribution from the other sex required. The Amazon molly, however, is far from celibate. These fish still mate with males from closely related species because they need sperm to kick-start the development of their embryos. But none of the male’s genetic material gets passed on to the next generation. © 2026 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Evolution
Link ID: 30158 - Posted: 03.14.2026

By Carl Zimmer Look at just about any vertebrate and you’ll see two eyes looking back at you. Falcons circling overhead have two eyes, just like hammerhead sharks roving through the ocean. Scientists have long puzzled over how the vertebrate eye first evolved. A pair of new studies suggest a strange beginning: Our invertebrate ancestors 560 million years ago were cyclopes, with a single eye at the top of their head, scientists now propose, that only later split in two. Charles Darwin fretted a lot about the exquisite complexity and sophistication of the vertebrate eye as he developed his theory of evolution. “The eye to this day gives me a cold shudder,” he confided to his friend, the American botanist Asa Gray, in 1860. Somehow evolution had produced the eye from many parts, such as the lens and retina, through tiny changes through the generations. Darwin couldn’t say for sure what that sequence of changes was. But he was encouraged by the diversity of simpler eyes among invertebrates. Some are mere lumps of pigment that detect light; others are simple cups lacking lenses. “When I think of the fine known gradations,” Darwin wrote to Gray, “my reason tells me I ought to conquer the cold shudder.” Yet opponents of evolution continued to cast doubt on the idea that eyes could evolve. Even in the 1990s, creationists claimed that natural selection would need many billions of years to produce an eye — far more time than life has existed on Earth. Dan-E. Nilsson, a neurobiologist at Lund University in Sweden, grew so annoyed by these claims that he estimated how long it would actually take for a patch of light-sensitive cells to evolve into an image-forming eye. “I thought, Heck, that’s an easy calculation, let’s do that,” Dr. Nilsson recalled. In 1994 he and Susanne Pelger, a colleague at Lund, concluded that an image-forming eye could evolve in just a few hundred thousand years. “It’s not precise in any way at all, but it goes to show that there is plenty of time for eyes to evolve,” Dr. Nilsson said. © 2026 The New York Times Company

Keyword: Evolution
Link ID: 30138 - Posted: 02.25.2026

By Hannah Thomasy In 1774, British physician-scientist Charles Blagden received an unusual invitation from a fellow physician: to spend time in a small room that was hotter, he wrote, “than it was formerly thought any living creature could bear.” Many people may have been appalled by this offer, but Blagden was delighted by the opportunity for self-experimentation. He marveled as his own temperature remained at 98 degrees Fahrenheit (approximately 37 degrees Celsius), even as the temperature of the room approached 200°F (about 93°C). Today, this ability to maintain a stable body temperature — called homeothermy — is known to exist among myriad species of mammals and birds. But there are also some notable exceptions. The body temperature of the fat-tailed dwarf lemur, for example, can fluctuate by nearly 45°F (25°C) over a single day. In fact, a growing body of research suggests that many more animals than scientists once appreciated employ this flexible approach — heterothermy — varying their body temperature for minutes, hours or weeks at a time. This may help the animals to persist through all sorts of dangers. “Because we’re homeotherms, we assume all mammals work the way we do,” says Danielle Levesque, a mammalian ecophysiologist at the University of Maine. But in recent years, as improvements in technology allowed researchers to more easily track small animals and their metabolisms in the wild, “we’re starting to find a lot more weirdness,” she says. The most extreme — and well-known — form of heterothermy is classic hibernation, which has been most extensively studied in critters who use it to save energy and so survive the long, cold winters of the Northern Hemisphere. These animals enter long periods of what scientists call deep torpor, when metabolism slows to a crawl and body temperature can drop to just above freezing.

Keyword: Evolution
Link ID: 30137 - Posted: 02.25.2026

By Meghan Bartels On March 7, 1949, researchers at the Woods Hole Oceanographic Institution (WHOI) were stationed on a boat called the R/V Atlantis that was sailing off the coast of Bermuda. They lowered a primitive underwater recording setup into the ocean, and a boxy machine more regularly found in offices began etching the sounds of the sea—a chorus of eerie howls and rustling waves—into a thin plastic disk. That disk made its way to WHOI’s archives in Massachusetts, where it sat, an overlooked relic of the earliest days of underwater acoustic recording. Fast-forward nearly eight decades, and experts at WHOI have rediscovered the recording and determined it’s probably the oldest whale recording still in existence. The likely vocalist? A humpback whale (Megaptera novaeangliae). The scientists who stumbled on the rare recording are eager to use it for science. “Data from this time period simply don’t exist in most cases,” said Laela Sayigh, a marine bioacoustician at WHOI, in a statement. “This recording can provide insight into how humpback whale sounds have changed over time, as well as serving as a baseline for measuring how human activity shapes the ocean soundscape.” The recording dates to a time when the North Atlantic Ocean’s humpback whales were struggling because of decades of commercial whaling. By 1955, the population had likely fallen below 1,000 animals, experts have since estimated. And although humpback whales are due for a thorough census, even outdated estimates suggest there are at least 20 to 25 times the number of these animals in the region today. © 2025 SCIENTIFIC AMERICAN,

Keyword: Animal Communication; Language
Link ID: 30131 - Posted: 02.21.2026

By Elizabeth Preston On the island of Golem Grad in North Macedonia, visitors may see a chain of tortoises mounting each other like a slow-moving, libidinous locomotive. It used to strike Dragan Arsovski, an ecologist at the Macedonian Ecological Society, as funny. Now that he knows what’s really going on, he isn’t laughing. This uninhabited island in a country that once was part of Yugoslavia is crawling with around 1,000 Hermann’s tortoises — especially males. They pursue mates aggressively, making life unhealthy and short for the island’s scarce females. Some of those females even die by walking off the island’s cliffs. In a paper published last month in the journal Ecology Letters, researchers have found that the relentless males are driving their population to extinction. The island, in Lake Prespa, has a forested plateau encircled by sheer cliffs. When Dr. Arsovski started studying the salad-plate-size tortoises in 2008, “it was quite a dense and seemingly prosperous population,” he said. But for some reason, there were far more adult males than females — 19 males for every female on the plateau, at the latest count. He and his colleagues documented how the males seemed to manage their carnal instincts by mounting each other. Then, after many years of study, Dr. Arsovski realized that the females were undersized and dying young. He also realized those once-comical copulatory trains were made up of many males pursuing just one female. When the female tired, the train would become a frenzied heap of reptiles. “She’s literally buried by males,” Dr. Arsovski said. He and his co-authors wrote that as part of the tortoises’ courtship, they “bump, bite (sometimes to the point of blood loss), mount and finally vigorously poke fleeing females” with a sharp tail tip. Three-quarters of the island’s females had genital injuries. © 2026 The New York Times Company

Keyword: Aggression; Sexual Behavior
Link ID: 30125 - Posted: 02.18.2026