Chapter 6. Evolution of the Brain and Behavior

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By Virginia Morell Leaping over waves or body surfing side by side, dolphins are a fun-loving bunch. But their frolicking—and that of species from hyenas to humans—has long baffled evolutionary biologists. Why expend so much energy on play? A new study offers an intriguing explanation: Juvenile male dolphins use play to acquire the skills required for fathering calves, researchers report today in the Proceedings of the National Academy of Sciences. Most significantly, the scientists found the most playful males go on to have more calves as adults. The study is likely to spur further research into play behavior in additional species, other scientists say. “It’s exciting research, and it solves an evolutionary puzzle,” says Jennifer Smith, a behavioral ecologist at the University of Wisconsin–Eau Claire. “This is the first study to link play behavior in the wild to reproductive success.” Since 1982, scientists have observed some 200 male Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the exceptionally clear waters of Shark Bay in Australia. About 20 years ago, the researchers noticed that young males, 4 to 12 years old, often played together as if they were herding a fertile female, flanking her on either side, while swimming in sync with each other and making popping vocalizations. This kind of “synchronicity is crucial for male reproduction,” says Kathryn Holmes, a behavioral biologist with the Shark Bay Dolphin Research project and lead author of the new study. The young dolphins’ behaviors were strikingly similar to those of the adults. “We wondered if this was ‘play practice’ for the adult behaviors,” Holmes says. So she and her colleagues closely tracked 28 juvenile males for 4 to 5 months over several years, recording their interactions and play behaviors. When socializing, the males “played almost continuously,” Holmes says. “They seemed to never tire of their games.” © 2024 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Evolution
Link ID: 29353 - Posted: 06.11.2024

Elephants call out to each other using individual names that they invent for their fellow pachyderms, according to a new study. While dolphins and parrots have been observed addressing each other by mimicking the sound of others from their species, elephants are the first non-human animals known to use names that do not involve imitation, the researchers suggested. For the new study published on Monday, a team of international researchers used an artificial intelligence algorithm to analyse the calls of two wild herds of African savanna elephants in Kenya. The research “not only shows that elephants use specific vocalisations for each individual, but that they recognise and react to a call addressed to them while ignoring those addressed to others”, the lead study author, Michael Pardo, said. The video player is currently playing an ad. “This indicates that elephants can determine whether a call was intended for them just by hearing the call, even when out of its original context,” the behavioural ecologist at Colorado State University said in a statement. The researchers sifted through elephant “rumbles” recorded at Kenya’s Samburu national reserve and Amboseli national park between 1986 and 2022. Using a machine-learning algorithm, they identified 469 distinct calls, which included 101 elephants issuing a call and 117 receiving one. Elephants make a wide range of sounds, from loud trumpeting to rumbles so low they cannot be heard by the human ear. Names were not always used in the elephant calls. But when names were called out, it was often over a long distance, and when adults were addressing young elephants. Adults were also more likely to use names than calves, suggesting it could take years to learn this particular talent. The most common call was “a harmonically rich, low-frequency sound”, according to the study in the journal Nature Ecology & Evolution. © 2024 Guardian News & Media Limited

Keyword: Animal Communication; Language
Link ID: 29352 - Posted: 06.11.2024

By Betsy Mason To help pay for his undergraduate education, Elias Garcia-Pelegrin had an unusual summer job: cruise ship magician. “I was that guy who comes out at dinnertime and does random magic for you,” he says. But his latest magic gig is even more unusual: performing for Eurasian jays at Cambridge University’s Comparative Cognition Lab. Birds can be harder to fool than tourists. And to do magic for the jays, he had to learn to do sleight-of-hand tricks with a live, wriggling waxworm instead of the customary coin or ball. But performing in an aviary does have at least one advantage over performing on a cruise ship: The birds aren’t expecting to be entertained. “You don’t have to worry about impressing anybody, or tell a joke,” Garcia-Pelegrin says. “So you just do the magic.” In just the last few years, researchers have become interested in what they can learn about animal minds by studying what does and doesn’t fool them. “Magic effects can reveal blind spots in seeing and roadblocks in thinking,” says Nicky Clayton, who heads the Cambridge lab and, with Garcia-Pelegrin and others, cowrote an overview of the science of magic in the Annual Review of Psychology. What we visually perceive about the world is a product of how our brains interpret what our eyes see. Humans and other animals have evolved to handle the immense amount of visual information we’re exposed to by prioritizing some types of information, filtering out things that are usually less relevant and filling in gaps with assumptions. Many magic effects exploit these cognitive shortcuts in humans, and comparing how well these same tricks work on other species may reveal something about how their minds operate. Clayton and her colleagues have used magic tricks with both jays and monkeys to reveal differences in how these animals experience the world. Now they are hoping to expand to more species and inspire other researchers to try magic to explore big questions about complex mental abilities and how they evolved.

Keyword: Attention; Evolution
Link ID: 29345 - Posted: 06.06.2024

By Mariana Lenharo Crows know their numbers. An experiment has revealed that these birds can count their own calls, showcasing a numerical skill previously only seen in people. Investigating how animals understand numbers can help scientists to explore the biological origins of humanity’s numerical abilities, says Giorgio Vallortigara, a neuroscientist at the University of Trento in Rovereto, Italy. Being able to produce a deliberate number of vocalizations on cue, as the birds in the experiment did, “is actually a very impressive achievement”, he notes. Andreas Nieder, an animal physiologist at the University of Tübingen in Germany and a co-author of the study published 23 May in Science1, says it was amazing to see how cognitively flexible these corvids are. “They have a reputation of being very smart and intelligent, and they proved this once again.” The researchers worked with three carrion crows (Corvus corone) that had already been trained to caw on command. Over the next several months, the birds were taught to associate visual cues — a screen showing the digits 1, 2, 3 or 4 — with the number of calls they were supposed to produce. They were later also introduced to four auditory cues that were each associated with a distinct number. During the experiment, the birds stood in front of the screen and were presented with a visual or auditory cue. They were expected to produce the number of vocalizations associated with the cue and to peck at an ‘enter key’ on the touchscreen monitor when they were done. If they got it right, an automated feeder delivered bird-seed pellets and mealworms as a reward. They were correct most of the time. “Their performance was way beyond chance and highly significant,” says Nieder. © 2024 Springer Nature Limited

Keyword: Attention; Evolution
Link ID: 29326 - Posted: 05.25.2024

By Kermit Pattison Since the Stone Age, hunters have brought down big game with spears, atlatls, and bows and arrows. Now, a new study reveals traditional societies around the globe also relied on another deadly but often-overlooked weapon: our legs. According to a report published today in Nature Human Behaviour, running down big game such as antelope, moose, and even kangaroos was far more widespread than previously recognized. Researchers documented nearly 400 cases of endurance pursuits—a technique in which prey are chased to exhaustion—by Indigenous peoples around the globe between the 16th and 21st centuries. And in some cases, they suggest, it can be more efficient than stealthy stalking. The findings bolster the idea that humans evolved to be hunting harriers, says Daniel Lieberman, an evolutionary biologist at Harvard University. “Nobody else has come up with any other explanation for why humans evolved to run long distances,” says Lieberman, who adds that he’s impressed with the paper’s “depth of scholarship.” For decades, some anthropologists have argued that endurance running was among the first hunting techniques employed by early hominins in Africa. Advocates suggest subsequent millennia spent chasing down prey shaped many unique human features, including our springy arched feet, slow-twitch muscle fibers optimized for efficiency, heat-shedding bare skin, and prodigious ability to sweat. The “born to run” idea has become something of an origin story among many endurance athletes. But a pack of skeptics has dogged the theory. Critics cited the higher energetic costs of running over walking and noted that accounts of persistence hunting among modern foragers are rare. Yet hints of such pursuits kept popping up as Eugène Morin, an archaeologist at Trent University and co-author of the new paper, scoured the literature for a book he was writing on hunting among traditional societies. As he pored over early accounts by missionaries, travelers, and explorers, he repeatedly found descriptions of long-distance running and tracking. © 2024 American Association for the Advancement of Science.

Keyword: Evolution
Link ID: 29309 - Posted: 05.16.2024

By Jake Buehler Sounding like a toxic moth might keep some beetles safe from hungry bats. When certain tiger beetles hear an echolocating bat draw near, they respond with extremely high-pitched clicks. This acoustic countermeasure is a dead ringer for the noises toxic moths make to signal their nasty taste to bats, researchers report May 15 in Biology Letters. Such sound-based mimicry may be widespread among groups of night-flying insects, the scientists say. At night, bats and bugs are locked in sonic warfare. At least seven major insect groups have ears sensitive to bat echolocation pitches, and many often flee in response. Some moths have sound-absorbent wings and fuzz that impart stealth against bat sonar (SN: 11/14/18). Others use their genitals to make ultrasonic trills — above the range of human hearing — that may startle bats or jam their sonar (SN: 7/3/13). Previous research suggested some tiger beetles — a family of fast-running, often strikingly colored predatory beetles with strong jaws — also make high-pitched clicks as a response to human-made imitations of bat ultrasound. So Harlan Gough, a conservation entomologist now at the U.S. Fish and Wildlife Service in Burbank, Wash., and his colleagues set out to answer why. The researchers collected 19 tiger beetle species from southern Arizona and brought them into the lab. They tethered the insects to a metal rod and prompted them to fly. The team then filmed and recorded audio to see how the beetles responded to playback of a bat clicking sequence that immediately precedes an attack. Right away, seven of these species — all nocturnal fliers — pulled their hard, case-like forewings into the path of their beating hindwings. The resulting collisions made high-pitched clicking noises. © Society for Science & the Public 2000–2024.

Keyword: Hearing; Evolution
Link ID: 29308 - Posted: 05.16.2024

By Emily Anthes Half a century ago, one of the hottest questions in science was whether humans could teach animals to talk. Scientists tried using sign language to converse with apes and trained parrots to deploy growing English vocabularies. The work quickly attracted media attention — and controversy. The research lacked rigor, critics argued, and what seemed like animal communication could simply have been wishful thinking, with researchers unconsciously cuing their animals to respond in certain ways. In the late 1970s and early 1980s, the research fell out of favor. “The whole field completely disintegrated,” said Irene Pepperberg, a comparative cognition researcher at Boston University, who became known for her work with an African gray parrot named Alex. Today, advances in technology and a growing appreciation for the sophistication of animal minds have renewed interest in finding ways to bridge the species divide. Pet owners are teaching their dogs to press “talking buttons” and zoos are training their apes to use touch screens. In a cautious new paper, a team of scientists outlines a framework for evaluating whether such tools might give animals new ways to express themselves. The research is designed “to rise above some of the things that have been controversial in the past,” said Jennifer Cunha, a visiting research associate at Indiana University. The paper, which is being presented at a science conference on Tuesday, focuses on Ms. Cunha’s parrot, an 11-year-old Goffin’s cockatoo named Ellie. Since 2019, Ms. Cunha has been teaching Ellie to use an interactive “speech board,” a tablet-based app that contains more than 200 illustrated icons, corresponding to words and phrases including “sunflower seeds,” “happy” and “I feel hot.” When Ellie presses on an icon with her tongue, a computerized voice speaks the word or phrase aloud. In the new study, Ms. Cunha and her colleagues did not set out to determine whether Ellie’s use of the speech board amounted to communication. Instead, they used quantitative, computational methods to analyze Ellie’s icon presses to learn more about whether the speech board had what they called “expressive and enrichment potential.” © 2024 The New York Times Company

Keyword: Language; Epilepsy
Link ID: 29306 - Posted: 05.14.2024

By Lee Alan Dugatkin 1 The complexity of animal social behavior is astonishing I have studied animal behavior for more than 35 years, so I’m rarely surprised at just how nuanced, subtle, and complex the social behavior of nonhuman animals can be. But, every once in a while, that “my goodness, how astonishing!” feeling—which I felt so often in graduate school—returns. That’s how I felt when I read Kevin Oh and Alexander Badyaev’s work on sexual selection and social networks in house finches (Haemorhous mexicanus). The house finches in question, I learned while researching my book, live on the campus of the University of Arizona, where, in 2003, Oh was doing his graduate work and Badyaev was a young assistant professor. Using data on thousands of finches they banded over six years, these two researchers were able to map the social network the birds relied on during breeding season. This network was composed of 25 “neighborhoods” with an average of 30 finches per group. Females rarely left their neighborhoods to interact with birds in other neighborhoods. But how much males moved around from one neighborhood to the next depended on their coloring. Those with plenty of red coloration—which females tend to prefer as mating partners—generally remained put, just like females. But drabber colored males were more likely to socialize across many neighborhoods. The question was why? The answer was what rekindled my own sense of awe in the power of natural selection to shape animal social behavior. When Oh and Bedyaev mapped reproductive success in their house finches, they found that the most colorful males did well no matter what neighborhood they were in. Drab males, however, had greater reproductive success if they tried their luck all around town—essentially, this allowed them to find just the spot where their relative coloration was greatest and therefore most likely to score them a mate. In other words, they learned to play the field, restructuring social networks in a way that served their purposes best. 2 Technology is radically changing how scientists study the behavior of animals © 2024 NautilusNext Inc.,

Keyword: Learning & Memory; Evolution
Link ID: 29305 - Posted: 05.14.2024

By Gillian Dohrn “Puppy-dog eyes didn’t just evolve for us, in domestic dogs,” says comparative anatomist Heather Smith. Her team’s work has thrown a 2019 finding1 that the muscles in dogs’ eyebrows evolved to communicate with humans in the doghouse by showing that African wild dogs also have the muscles to make the infamous pleading expression. The study was published on 10 April in The Anatomical Record2. Now, one of the researchers who described the evolution of puppy-dog eyebrow muscles is considering what the African dog discovery means for canine evolution. “It opens a door to thinking about where dogs come from, and what they are,” says Anne Burrows, a biological anthropologist at the Duquesne University in Pittsburgh, Pennsylvania, and author of the earlier paper. The 2019 study garnered headlines around the world when it found that the two muscles responsible for creating the sad–sweet puppy-dog stare are pronounced in several domestic breeds (Canis familiaris), but almost absent in wolves (Canis lupus). If the social dynamic between humans and dogs drove eyebrow evolution, Smith wondered whether the highly social African wild dog might also have expressive brows. African wild dogs (Lycaon pictus) are native to sub-Saharan Africa. Between 1997 and 2012, their numbers dropped by half in some areas. With only 8,000 or so remaining in the wild, studying them is difficult but crucial for conservation efforts. Smith, who is based at Midwestern University in Glendale, Arizona, and her colleagues dissected a recently deceased African wild dog from Phoenix Zoo. They found that both the levator anguli oculi medalis (LAOM) and the retractor anguli oculi lateralis (RAOL) muscles, credited with creating the puppy-dog expression, were similar in size to those of domestic dog breeds.

Keyword: Emotions; Sexual Behavior
Link ID: 29295 - Posted: 05.07.2024

By Gayathri Vaidyanathan An orangutan in Sumatra surprised scientists when he was seen treating an open wound on his cheek with a poultice made from a medicinal plant. It’s the first scientific record of a wild animal healing a wound using a plant with known medicinal properties. The findings were published this week in Scientific Reports1. “It shows that orangutans and humans share knowledge. Since they live in the same habitat, I would say that’s quite obvious, but still intriguing to realize,” says Caroline Schuppli, a primatologist at the Max Planck Institute of Animal Behavior in Konstanz, Germany, and a co-author of the study. In 2009, Schuppli’s team was observing Sumatran orangutans (Pongo abelii) in the Gunung Leuser National Park in South Aceh, Indonesia, when a young male moved into the forest. He did not have a mature male’s big cheek pads, called flanges, and was probably around 20 years old, Schuppli says. He was named Rakus, or ‘greedy’ in Indonesian, after he ate all the flowers off a gardenia bush in one sitting. In 2021, Rakus underwent a growth spurt and became a mature flanged male. The researchers observed Rakus fighting with other flanged males to establish dominance and, in June 2022, a field assistant noted an open wound on his face, possibly made by the canines of another male, Schuppli says. Days later, Rakus was observed eating the stems and leaves of the creeper akar kuning (Fibraurea tinctoria), which local people use to treat diabetes, dysentery and malaria, among other conditions. Orangutans in the area rarely eat this plant. In addition to eating the leaves, Rakus chewed them without swallowing and used his fingers to smear the juice on his facial wound over seven minutes. Some flies settled on the wound, whereupon Rakus spread a poultice of leaf-mash on the wound. He ate the plant again the next day. Eight days after his injury, his wound was fully closed. © 2024 Springer Nature Limited

Keyword: Learning & Memory; Evolution
Link ID: 29290 - Posted: 05.03.2024

By Tim Vernimmen Most amphibians aren’t exactly doting parents — they just find a partner and release as many eggs or sperm as possible, in hopes that viable larvae will hatch from at least some fertilized eggs, and at least some of those larvae will survive to adulthood. Yet in as many as one in five amphibian species, one or both parents stick around to care for their offspring, using a staggering variety of strategies. The most well-known amphibian parents are the brightly colored poison frogs, a group of around 200 species that will repeatedly be leaping into view in this article. Yet their parenting skills may not be as exceptional as once thought, says biologist Jennifer Stynoski of the University of Costa Rica, who decided to study this group when she spotted them on a field trip as a student years ago. “I think they’ve just received a lot of attention because they’re so beautiful. They’re very cute to study.” So — what makes an exemplary amphibian parent? Much remains to be discovered, but some common principles have emerged. Stay away from the water Unlike reptiles and the birds that evolved from them, the ancestors of today’s amphibians never developed eggs with tough, watertight shells. This means their eggs need water to survive, as do the gilled larvae that usually come wriggling out. Yet the ponds in which many amphibians deposit their eggs are full of other animals, many eager to supplement their diet by slurping up a mouthful of eggs. “This must be one reason why so many species have evolved ways to lay their eggs away from the water,” says behavioral ecologist Eva Ringler of the University of Bern in Switzerland. © 2024 Annual Reviews

Keyword: Sexual Behavior; Evolution
Link ID: 29279 - Posted: 04.30.2024

By Kristen French Combat in nature is often a matter of tooth and claw, fang and talon. But some creatures have devised devious and dramatic ways to weaponize their bodily fluids, expelling them in powerful streams for the purposes of attack or self-defense. Researcher Elio Challita became fascinated by fluid ejections in nature when he began studying an insect called the sharpshooter, which pees one droplet at a time using a method called superpropulsion. These insects consume 300 times their own body weight per day in xylem sap, a watery solution of minerals and other nutrients found in the roots, stems, and leaves of plants. To efficiently expel the resulting waste, they use a kind of internal catapult that helps overcome the surface tension in the droplets. Challita and a team of researchers from the Bhamla Lab at Georgia Tech decided to survey the biomechanics and fluid dynamics that govern fluid ejections across the animal kingdom to see what commonalities they could find. Among others, they identified a number of creatures that use bodily fluids as powerful weapons in the fight for survival. These fluid ejections defy gravity and rebel against traditional notions of predator-prey tactics. The team’s review, “Fluid Ejections in Nature,” is forthcoming in the Annual Review of Chemical and Biological Engineering. 1. Ringnecked Spitting Cobra Cobras of the Naja genus defend against threats by spitting venom with extreme precision toward the eyes of an enemy, up to 6.5 feet away. These snakes release the venom through hollow microscopic fangs and can adjust the distribution of their spit with rapid movements. Spitting cobras have a venom discharge orifice that is more circular in shape than non-spitting species, which gives the venom more forward force. Contraction in the venom gland also helps. A 90-degree bend near the lip of the orifice gives the snake more precise control over venom flow. Naja pallida cobras can spit venom at average speeds of 1.27 milliliters per second. © 2024 NautilusNext Inc.,

Keyword: Neurotoxins; Evolution
Link ID: 29278 - Posted: 04.30.2024

By Claire Cameron On Aug. 19, 2021, a humpback whale named Twain whupped back. Specifically, Twain made a series of humpback whale calls known as “whups” in response to playback recordings of whups from a boat of researchers off the coast of Alaska. The whale and the playback exchanged calls 36 times. On the boat was naturalist Fred Sharpe of the Alaska Whale Foundation, who has been studying humpbacks for over two decades, and animal behavior researcher Brenda McCowan, a professor at the University of California, Davis. The exchange was groundbreaking, Sharpe says, because it brought two linguistic beings—humans and humpback whales—together. “You start getting the sense that there’s this mutual sense of being heard.” In their 2023 published results, McGowan, Sharpe, and their coauthors are careful not to characterize their exchange with Twain as a conversation. They write, “Twain was actively engaged in a type of vocal coordination” with the playback recordings. To the paper’s authors, the interspecies exchange could be a model for perhaps something even more remarkable: an exchange with an extraterrestrial intelligence. Sharpe and McGowan are members of Whale SETI, a team of scientists at the SETI Institute, which has been scanning the skies for decades, listening for signals that may be indicative of extraterrestrial life. The Whale SETI team seeks to show that animal communication, and particularly, complex animal vocalizations like those of humpback whales, can provide scientists with a model to help detect and decipher a message from an extraterrestrial intelligence. And, while they’ve been trying to communicate with whales for years, this latest reported encounter was the first time the whales talked back. It all might sound far-fetched. But then again, Laurance Doyle, an astrophysicist who founded the Whale SETI team and has been part of the SETI Institute since 1987, is accustomed to being doubted by the mainstream science community. © 2024 NautilusNext Inc.,

Keyword: Animal Communication; Language
Link ID: 29276 - Posted: 04.30.2024

By Shaena Montanari The sympathetic nervous system may have originated in jawless fish—not tens of millions of years later as previously thought, according to a study published today in Nature. Anatomical work dating back to the 19th century suggested that the sympathetic nervous system was present only in jawed vertebrates. Yet the sea lamprey, the new findings reveal, sports clusters of sympathetic neurons along its trunk and expresses several genes involved in the “fight-or-flight” system, the response that kicks into gear when an animal perceives a threat. “Whenever new research causes troves of textbooks to need corrections, that’s always surprising,” says Tyler Square, assistant professor of molecular genetics at the University of Florida, who was not involved in the study. The team behind the new work decided to re-examine conventional wisdom after a postdoctoral researcher in the lab produced microscopy images of lamprey embryos stained for neurons in the animals’ gut. The stain highlighted some “small sort of concentrations of cells” that looked a lot like sympathetic neurons, recalls lead investigator Marianne Bronner, professor of biology at the California Institute of Technology. “I said, ‘Oh, those shouldn’t be there.’ So then we decided to delve deeper into it.” The unexpected neurons express several key genes—specifically ASCL1, PHOX2 and HAND—involved in the sympathoadrenal system, the team discovered using a suite of techniques, including immunohistochemistry, in situ hybridization chain reaction and RNA sequencing. These are “all transcription factors that are known to be important in sympathetic neuron differentiation in mammals,” Bronner says. © 2024 Simons Foundation

Keyword: Stress; Evolution
Link ID: 29270 - Posted: 04.26.2024

By Bill Wasik and Monica Murphy What makes a desert tortoise happy? Before you answer, we should be more specific: We’re talking about a Sonoran desert tortoise, one of a few species of drab, stocky tortoises native to North America’s most arid landscapes. Adapted to the rocky crevices that striate the hills from western Arizona to northern Mexico, this long-lived reptile impassively plods its range, browsing wildflowers, scrub grasses and cactus paddles during the hours when it’s not sheltering from the brutal heat or bitter cold. Sonoran desert tortoises evolved to thrive in an environment so different from what humans find comfortable that we can rarely hope to encounter one during our necessarily short forays — under brimmed hats and layers of sunblock, carrying liters of water and guided by GPS — into their native habitat. This past November, in a large, carpeted banquet room on the University of Wisconsin’s River Falls campus, hundreds of undergraduate, graduate and veterinary students silently considered the lived experience of a Sonoran desert tortoise. Perhaps nine in 10 of the participants were women, reflecting the current demographics of students drawn to veterinary medicine and other animal-related fields. From 23 universities in the United States and Canada, and one in the Netherlands, they had traveled here to compete in an unusual test of empathy with a wide range of creatures: the Animal Welfare Assessment Contest. That morning in the banquet room, the academics and experts who organize the contest (under the sponsorship of the American Veterinary Medical Association, the nation’s primary professional society for vets) laid out three different fictional scenarios, each one involving a binary choice: Which animals are better off? One scenario involved groups of laying hens in two different facilities, a family farm versus a more corporate affair. Another involved bison being raised for meat, some in a smaller, more managed operation and others ranging more widely with less hands-on human contact. © 2024 The New York Times Company

Keyword: Animal Rights; Emotions
Link ID: 29268 - Posted: 04.24.2024

By Angie Voyles Askham The ability of amphibians to metamorphosize and, in some cases, regenerate limbs and even brain tissue raises puzzling yet fundamental questions about how a nervous system wires itself up. For example, if a frog’s legs don’t exist when its brain begins to develop—those limbs later replace its tadpole tail—how are the neural connections maintained such that, once the legs take shape, a frog can move them? “How many connections are there between the spinal cord and the brain? How do they change over metamorphosis?” asks Lora Sweeney, assistant professor at the Institute of Science and Technology Austria. To find out, Sweeney and her colleagues decided to screen a panel of adeno-associated viruses (AAVs) in two species of frog and a newt. These viruses are commonly used to genetically manipulate brain cells in rodents and monkeys, but they have not been proven useful in amphibian experiments. With the right techniques, most common AAVs can deliver genes to amphibian cells through a process called transduction, according to Sweeney’s unpublished results, though the most effective viruses vary by species. These amphibian-friendly AAVs can be used to trace neuronal connections and track groups of neurons born at the same time, the new work shows. And a subset of these same AAVs can also transduce cells in axolotls, newts’ fuzzy-gilled Mexican cousins, according to another preprint from an independent team. Both preprints were posted on bioRxiv in February. “It’s a big game-changer,” says Helen Willsey, assistant professor of psychiatry at the University of California, San Francisco, who was not involved in either study but works with amphibian models. “It opens up a lot of doors for new experiments.” Other researchers had previously tried to get AAVs to transduce cells in frogs and fish, with little success. © 2024 Simons Foundation

Keyword: Brain imaging; Evolution
Link ID: 29267 - Posted: 04.24.2024

By Dan Falk In 2022, researchers at the Bee Sensory and Behavioral Ecology Lab at Queen Mary University of London observed bumblebees doing something remarkable: The diminutive, fuzzy creatures were engaging in activity that could only be described as play. Given small wooden balls, the bees pushed them around and rotated them. The behavior had no obvious connection to mating or survival, nor was it rewarded by the scientists. It was, apparently, just for fun. The study on playful bees is part of a body of research that a group of prominent scholars of animal minds cited today, buttressing a new declaration that extends scientific support for consciousness to a wider suite of animals than has been formally acknowledged before. For decades, there’s been a broad agreement among scientists that animals similar to us — the great apes, for example — have conscious experience, even if their consciousness differs from our own. In recent years, however, researchers have begun to acknowledge that consciousness may also be widespread among animals that are very different from us, including invertebrates with completely different and far simpler nervous systems. The new declaration, signed by biologists and philosophers, formally embraces that view. It reads, in part: “The empirical evidence indicates at least a realistic possibility of conscious experience in all vertebrates (including all reptiles, amphibians and fishes) and many invertebrates (including, at minimum, cephalopod mollusks, decapod crustaceans and insects).” Inspired by recent research findings that describe complex cognitive behaviors in these and other animals, the document represents a new consensus and suggests that researchers may have overestimated the degree of neural complexity required for consciousness. © 2024the Simons Foundation.

Keyword: Consciousness; Evolution
Link ID: 29264 - Posted: 04.20.2024

By Carl Zimmer In the early 1900s, primatologists noticed a group of apes in central Africa with a distinctly slender build; they called them “pygmy chimpanzees.” But as the years passed, it became clear that those animals, now known as bonobos, were profoundly different from chimpanzees. Chimpanzee societies are dominated by males that kill other males, raid the territory of neighboring troops and defend their own ground with border patrols. Male chimpanzees also attack females to coerce them into mating, and sometimes even kill infants. Among bonobos, in contrast, females are dominant. Males do not go on patrols, form alliances or kill other bonobos. And bonobos usually resolve their disputes with sex — lots of it. Bonobos became famous for showing that nature didn’t always have to be red in tooth and claw. “Bonobos are an icon for peace and love, the world’s ‘hippie chimps,’” Sally Coxe, a conservationist, said in 2006. But these sweeping claims were not based on much data. Because bonobos live in remote, swampy rainforests, it has been much more difficult to observe them in the wild than chimpanzees. More recent research has shown that bonobos live a more aggressive life than their reputation would suggest. In a study based on thousands of hours of observations in the wild published on Friday, for example, researchers found that male bonobos commit acts of aggression nearly three times as often as male chimpanzees do. “There is no ‘hippie ape,’” said Maud Mouginot, a biological anthropologist at Boston University who led the analysis. As our closest living relatives, bonobos and chimpanzees can offer us clues about the roots of human behavior. We and the two species share a common ancestor that lived about 7 million years ago. About 5 million years later, bonobos split off from chimpanzees. © 2024 The New York Times Company

Keyword: Aggression; Evolution
Link ID: 29256 - Posted: 04.13.2024

By Maria Popova I once dreamed a kiss that hadn’t yet happened. I dreamed the angle at which our heads tilted, the fit of my fingers behind her ear, the exact pressure exerted on the lips by this transfer of trust and tenderness. Freud, who catalyzed the study of dreams with his foundational 1899 treatise, would have discounted this as a mere chimera of the wishful unconscious. But what we have since discovered about the mind — particularly about the dream-rich sleep state of rapid-eye movement, or REM, unknown in Freud’s day — suggests another possibility for the adaptive function of these parallel lives in the night. One cold morning not long after the kiss dream, I watched a young night heron sleep on a naked branch over the pond in Brooklyn Bridge Park, head folded into chest, and found myself wondering whether birds dream. The recognition that nonhuman animals dream dates at least as far back as the days of Aristotle, who watched a sleeping dog bark and deemed it unambiguous evidence of mental life. But by the time Descartes catalyzed the Enlightenment in the 17th century, he had reduced other animals to mere automatons, tainting centuries of science with the assumption that anything unlike us is inherently inferior. In the 19th century, when the German naturalist Ludwig Edinger performed the first anatomical studies of the bird brain and discovered the absence of a neocortex — the more evolutionarily nascent outer layer of the brain, responsible for complex cognition and creative problem-solving — he dismissed birds as little more than Cartesian puppets of reflex. This view was reinforced in the 20th century by the deviation, led by B.F. Skinner and his pigeons, into behaviorism — a school of thought that considered behavior a Rube Goldberg machine of stimulus and response governed by reflex, disregarding interior mental states and emotional response. © 2024 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 29216 - Posted: 03.26.2024

Ian Sample Science editor Dogs understand what certain words stand for, according to researchers who monitored the brain activity of willing pooches while they were shown balls, slippers, leashes and other highlights of the domestic canine world. The finding suggests that the dog brain can reach beyond commands such as “sit” and “fetch”, and the frenzy-inducing “walkies”, to grasp the essence of nouns, or at least those that refer to items the animals care about. “I think the capacity is there in all dogs,” said Marianna Boros, who helped arrange the experiments at Eötvös Loránd University in Hungary. “This changes our understanding of language evolution and our sense of what is uniquely human.” Scientists have long been fascinated by whether dogs can truly learn the meanings of words and have built up some evidence to back the suspicion. A survey in 2022 found that dog owners believed their furry companions responded to between 15 and 215 words. More direct evidence for canine cognitive prowess came in 2011 when psychologists in South Carolina reported that after three years of intensive training, a border collie called Chaser had learned the names of more than 1,000 objects, including 800 cloth toys, 116 balls and 26 Frisbees. However, studies have said little about what is happening in the canine brain when it processes words. To delve into the mystery, Boros and her colleagues invited 18 dog owners to bring their pets to the laboratory along with five objects the animals knew well. These included balls, slippers, Frisbees, rubber toys, leads and other items. At the lab, the owners were instructed to say words for objects before showing their dog either the correct item or a different one. For example, an owner might say “Look, here’s the ball”, but hold up a Frisbee instead. The experiments were repeated multiple times with matching and non-matching objects. © 2024 Guardian News & Media Limited

Keyword: Language; Learning & Memory
Link ID: 29214 - Posted: 03.26.2024