Chapter 6. Evolution of the Brain and Behavior

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Links 1 - 20 of 2022

Nicole Creanza and Kate Snyder How do individuals choose their mates? Why are some more successful at attracting mates than others? These age-old questions are broadly relevant to all animals, including human beings. Darwin’s theory of natural selection offers one way to answer them. Sometimes phrased as “survival of the fittest,” the theory can also apply to mate choice, predicting that it’s beneficial to choose the mate who’s best adapted to surviving in its environment — the fastest runner, the best hunter, the farmer with the highest yields. That’s a bit simplistic as a summary of human sexuality, of course, since people pair up in the context of complex social norms and gender roles that are uniquely human. Researchers like us do think, though, that mate choice in other animals is influenced by these kinds of perceived adaptations. It fits with scientists’ understanding of evolution: If females choose to mate with well-adapted males, their offspring might have a better chance of surviving as well. Advantageous traits wind up passed down and preserved in future generations. But in many species, males try to attract mates by displaying characteristics that seem to be decidedly non-adaptive. These signals – such as a dazzling tail on a peacock or a beautiful tune from a songbird – were originally a big wrench thrown into Darwin’s theory of natural selection. Traits like these seem to do the opposite of making an animal more likely to survive in its environment. A flashy tail display or a showy melody is cumbersome, and it announces you to predators as well as love interests. Darwin got so upset by this inconsistency that he said “The sight of a feather in a peacock’s tail, whenever I gaze at it, makes me sick.” © 2010–2019, The Conversation US, Inc.

Keyword: Sexual Behavior; Evolution
Link ID: 25979 - Posted: 02.22.2019

By Veronique Greenwood Sleep — that absurd, amazing habit of losing consciousness for hours on end — is so universal across the animal kingdom that we usually assume it is essential to survival. Now, however, scientists who repeatedly disturbed the sleep of more than a thousand fruit flies are reporting that less slumber may be necessary for sustaining life than previously thought, at least in one species. A handful of studies involving dogs and cockroaches going back to the late 19th century suggest that being deprived of sleep can result in a shortened life span. But the methods behind some of these studies can make it difficult to say whether the test subjects were harmed by sleep deprivation itself, or by the stress of the treatment they were given — such as being shaken constantly. The new study took a milder approach, in hope of seeing the true effects of sleep deprivation. The automated system the researchers developed for monitoring the flies kept track of their movements with cameras, scoring any extended period without movement as sleep. When they were not being awakened repeatedly, the males slept about 10 hours a day, females about five on average. To keep the flies awake, the researchers equipped the system with tiny motors that would gently tip the flies any time they went still for at least 20 seconds. With this method, researchers deprived flies of rest over the course of their entire lifetimes, tipping them hundreds of times a day such that if they were snoozing during those periods of stillness, they might have been able to sleep around 2.5 hours a day on average. “When the results came from that experiment, it was very surprising,” said Giorgio Gilestro, a professor at Imperial College London who is a co-author of the study, which was published Wednesday in Science Advances. © 2019 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 25978 - Posted: 02.21.2019

Nicola Davis The mystery of how the zebra got its stripes might have been solved: researchers say the pattern appears to confuse flies, discouraging them from touching down for a quick bite. The study, published in the journal Plos One, involved horses, zebras, and horses dressed as zebras. The team said the research not only supported previous work suggesting stripes might act as an insect deterrent, but helped unpick why, revealing the patterns only produced an effect when the flies got close. Dr Martin How, co-author of the research from the University of Bristol, said: “The flies seemed to be behaving relatively naturally around both [zebras and horses], until it comes to landing. “We saw that these horseflies were coming in quite fast and almost turning away or sometimes even colliding with the zebra, rather than doing a nice, controlled flight.” Researchers made their discovery by spending more than 16 hours standing in fields and noting how horseflies interacted with nine horses and three zebras – including one somewhat bemusingly called Spot. While horseflies circled or touched the animals at similar rates, landing was a different matter, with a lower rate seen for zebras than horses. To check the effect was not caused by a different smell of zebras and horses, for example, the researchers put black, white and zebra-striped coats on seven horses in turn. While there was no difference in the rate at which the flies landed on the horses’ exposed heads, they touched and landed on the zebra coat far less often than either the black or white garment. © 2019 Guardian News & Media Limited

Keyword: Vision; Evolution
Link ID: 25977 - Posted: 02.21.2019

Jules Howard It’s a bit garbled but you can definitely hear it in the mobile phone footage. As the chimpanzees arrange their branches into a makeshift ladder and one of them makes its daring escape from its Belfast zoo enclosure, some words ring out loud and clear: “Don’t escape, you bad little gorilla!” a child onlooker shouts from the crowd. And … POP … with that a tiny explosion goes off inside my head. Something knocks me back about this sentence. It’s a “kids-say-the-funniest things” kind of sentence, and in any other situation I’d offer a warm smile and a chuckle of approval. But not this time. This statement has brought out the pedant in me. At this point, you may wonder if I’m capable of fleshing out a 700-word article chastising a toddler for mistakenly referring to a chimpanzee as a gorilla. The good news is that, though I am more than capable of such a callous feat, I don’t intend to write about this child’s naive zoological error. In fact, this piece isn’t really about the (gorgeous, I’m sure) child. It’s about us. You and me, and the words we use. So let’s repeat it. That sentence, I mean. “Don’t escape, you bad little gorilla!” the child shouted. The words I’d like to focus on in this sentence are the words “you” and “bad”. The words “you” and “bad” are nice examples of a simple law of nearly all human languages. They are examples of Zipf’s law of abbreviation, where more commonly used words in a language tend to be shorter. It’s thought that this form of information-shortening allows the transmission of more complex information in a shorter amount of time, and it’s why one in four words you and I write or say is likely to be something of the “you, me, us, the, to” variety. © 2019 Guardian News & Media Limited

Keyword: Language; Evolution
Link ID: 25971 - Posted: 02.18.2019

By Lee Dugatkin Like many breakthroughs in science, Dmitri Belyaev’s silver fox domestication experiment began with a thunderbolt: one simple, powerful, new idea. Born of a parish priest in early 20th century Russia, the geneticist proposed that all domestic animals were tamed through a generations-long process in which our distant ancestors repeatedly chose the calmest animals — those that were friendliest to people — for breeding. Whether horses for transport, dogs for protection, pigs for food, or oxen for labor, the essential trait was that the animals not try to bite the hand that fed them. Belyaev went on to speculate that all of the other characteristics we tend to see in domesticated species — their curly tails, floppy ears, juvenile facial, and body features — were somehow byproducts of this selection for the friendliest of the friendly. As a test, Belyaev decided that he would build a dog out of a fox, in real time, to understand how man’s best friend came to be. No one had ever attempted anything like it. No matter, he would try. At the time, in Stalinist Russia, the idea was considered radical and out of line with State orthodoxy. There were men who might very well have thrown the scientist in prison for what he was dreaming. But he would perform his magic in a far off, frozen land: The Siberian town of Novosibirsk, where winter temperatures can plummet to a bone-chilling -50 degrees Fahrenheit. Some 60 years later, his experiment is still going. It is one of the longest running science experiments ever, having outlived even its creator. And after all this time, it is still shaping the way we think about fundamental questions in biology — and even influencing the way we understand our own evolutionary trajectory. Copyright 2019 Undark

Keyword: Evolution
Link ID: 25940 - Posted: 02.08.2019

By Alex Fox If math is the language of the universe, bees may have just uttered their first words. New research suggests these busybodies of the insect world are capable of addition and subtraction—using colors in the place of plus and minus symbols. In the animal kingdom, the ability to count—or at least distinguish between differing quantities—isn’t unusual: It has been seen in frogs, spiders, and even fish. But solving equations using symbols is rare air, so far only achieved by famously brainy animals such as chimpanzees and African grey parrots. Enter the honey bee (Apis mellifera). Building on prior research that says the social insects can count to four and understand the concept of zero, researchers wanted to test the limits of what their tiny brains can do. Scientists trained 14 bees to link the colors blue and yellow to addition and subtraction, respectively. They placed the bees at the entrance of a Y-shaped maze, where they were shown several shapes in either yellow or blue. If the shapes were blue, bees got a reward if they went to the end of the maze with one more blue shape (the other end had one less blue shape); if the shapes were yellow, they got a reward if they went to the end of the maze with one less yellow shape. © 2018 American Association for the Advancement of Science

Keyword: Attention; Evolution
Link ID: 25938 - Posted: 02.08.2019

By Jordana Cepelewicz Genitals are among the fastest-evolving features in the animal kingdom. They’re also among the most diverse, arrayed in all shapes and sizes, adorned with spines, hooks and even teeth. Ducks have corkscrew-shaped genitalia. The male sea horse has a brood pouch that receives his mate’s eggs for fertilization and in which he nurtures the resulting offspring until birth. Female cabbage white butterflies have a hinged jaw inside their genital tract. Nature is full of strange reproductive organs with unusual uses. For the most part, though, certain genital morphologies are associated with males, others with females. But in 2014, a tiny insect called the barklouse broke even that rule when researchers reported that the females of all four species of a genus found in the caves of Brazil had a penis. It didn’t just look like a penis but acted like one, too: a penetrative organ the female insects used to anchor themselves to their mates during copulation. Moreover, complementary changes in the genitalia of the males had left them with a small pumping mechanism inside a membranous “vagina-like” cavity. Content from The Coca-Cola Company Sustainability and closed-loop recycling systems must now become a global priority, from emerging nations to the world's largest economies. Read More The finding not only piqued widespread interest (and amusement — the team was awarded a comedic Ig Nobel Prize in 2017), but also led to a debate about whether the scientists involved were correct to refer to the structure, called a gynosome, as a “female penis.” (Some experts, for instance, disagree with that characterization because the gynosome collects sperm rather than delivering it.) © 1996-2019 The Washington Post

Keyword: Sexual Behavior; Evolution
Link ID: 25928 - Posted: 02.04.2019

Jon Hamilton For comedian Lewis Black, anger is a job. Black is famous for his rants about stuff he finds annoying or unfair or just plain infuriating. Onstage, he often looks ready for a fight. He leans forward. He shouts. He stabs the air with an index finger, or a middle finger. To a scientist, Black looks a lot like a belligerent dog, or an irritated gerbil. "Practically every sexually reproducing, multicellular animal shows aggressive behavior," says David Anderson, a professor of biology at Caltech and co-author of the book The Neuroscience of Emotion. "Fruit flies show aggression." When I relay that last bit to Black, he's skeptical. "Really?" he says. "Come on." But Anderson, whose lab studies fruit flies, says the evidence is compelling. "They fight over females, they fight over food, they threaten each other, they put their wings up in the air, they charge at each other," he says. But does aggressive behavior mean a fruit fly gets angry the way Black does? Anderson says that depends on how you define the term. "We use anger subjectively to refer to our experience, our conscious experience, of rage, the feeling that you are about to explode, the feeling of irritation," he says. Black feels that way a lot. And he has spent decades thinking about how anger works in his own brain. "My anger comes from a collection of things that occur during the course of a day that build up," he says. "So by the end of a day, six or seven things have happened to me that have gone into my anger bank." © 2019 npr

Keyword: Emotions; Evolution
Link ID: 25917 - Posted: 01.31.2019

Ewen Callaway Neanderthals and Denisovans might have lived side by side for tens of thousands of years, scientists report in two papers in Nature1,2. The long-awaited studies are based on the analysis of bones, artefacts and sediments from Denisova Cave in southern Siberia, which is dotted with ancient-human remains. They provide the first detailed history of the site’s 300,000-year occupation by different groups of ancient humans. “We can now tell the whole story of the entire cave, not just bits and pieces,” says Zenobia Jacobs, a geochronologist at the University of Wollongong, Australia, who co-led one of the studies. Soviet archaeologists began unravelling the story of Denisova Cave, at the foot of the Altai Mountains, in the early 1980s. Since then, scientists have found the fragmentary remains of nearly a dozen ancient humans at the site. The cave became world famous in 2010, after an analysis of the DNA from a tiny hominin finger bone found that the creature was distinct from both modern humans and Neanderthals3. It belonged to a previously unknown hominin group, later named Denisovans. Additional sequencing of the DNA in bone remains from the cave found that Denisovans were a sister group to Neanderthals, and might once have lived across Asia — where they interbred with the ancestors of some humans now living there4. © 2019 Springer Nature Publishing AG

Keyword: Evolution
Link ID: 25916 - Posted: 01.31.2019

By Elizabeth Pennisi TAMPA, FLORIDA—Swimming through the oceans, voraciously consuming plankton and other small creatures—and occasionally startling a swimmer—the beautiful gelatinous masses known as comb jellies won’t be joining Mensa anytime soon. But these fragile creatures have nerve cells—and they offer insights about the evolutionary origins of all nervous systems, including our own. Inspired by studies of a glue-secreting cell unique to these plankton predators, researchers have now proposed that neurons emerged in the last common ancestor of today’s animals—and that their progenitors were secretory cells, whose primary function was to release chemicals into the environment. Joseph Ryan, a computational evolutionary biologist the University of Florida Whitney Laboratory for Marine Bioscience in St. Augustine, suggested that scenario last year after tracing the development of nerve cells in embryos of comb jellies, among the most ancient animals. Earlier this week at the annual meeting of the Society for Integrative and Comparative Biology (SICB) here, he marshaled evidence from developmental studies of other animals, all pointing to common origins for some neuron and secretory cells. “What Ryan is proposing is novel and important,” says David Plachetzki, an evolutionary biologist at the University of New Hampshire in Durham. Among other mysteries, it could resolve a long debate about whether the nervous system evolved twice early in animal life. © 2018 American Association for the Advancement of Science

Keyword: Evolution
Link ID: 25857 - Posted: 01.11.2019

Bruce Bower An ancient hominid skeleton dubbed Little Foot possessed a brain largely similar to that of modern chimpanzees and an inner ear with a mix of apelike and humanlike features, two studies suggest. These findings, along with other analyses of the adult female’s 3.67-million-year-old skeleton, point to the piecemeal evolution of humanlike traits in close relatives of our species, scientists say. The research is part of the first formal analyses of Little Foot’s skeleton, which was discovered more than 20 years ago in a South African cave but was recently removed from its rocky encasing. Other analyses of trunk and limb bones indicate that Little Foot, who lived perhaps a million years before the emergence of the human genus, Homo, already walked upright about as well as people today do (SN: 1/19/19, p.13). Although Little Foot consists of a nearly complete skeleton, her evolutionary identity is controversial. Paleoanthropologist Ronald Clarke of the University of the Witwatersrand in Johannesburg — Little Foot’s discoverer and a coauthor of the two new studies — assigns the find to Australopithecus prometheus, an early extinct hominid species that many scientists don’t regard as valid. Other researchers regard Little Foot as an early member of Australopithecus africanus, a species previously known from fossils discovered at several South African sites (SN: 1/19/19, p. 13). |© Society for Science & the Public 2000 - 2018

Keyword: Evolution
Link ID: 25855 - Posted: 01.10.2019

By Elizabeth Pennisi American Kennel Club descriptions of dog breeds can read like online dating profiles: The border collie is a workaholic; the German shepherd will put its life on the line for loved ones. Now, in the most comprehensive study of its kind to date, scientists have shown that such distinct breed traits are actually rooted in a dog’s genes. The findings may shed light on human behaviors as well. “It’s a huge advance,” says Elaine Ostrander, a mammalian geneticist at the National Human Genome Research Institute in Bethesda, Maryland, who was not involved with the work. “It’s a finite number of genes, and a lot of them do make sense.” When the dog genome was sequenced in 2005, scientists thought they would quickly be able to pin down the genes that give every breed its hallmark personality. But they found so much variation even within a breed that they could never study enough dogs to get meaningful results. So in the new study, Evan MacLean, a comparative psychologist at the University of Arizona in Tucson, and colleagues began by looking at behavioral data for about 14,000 dogs from 101 breeds. The analyses come from the Canine Behavioral Assessment & Research Questionnaire (C-BARQ), a sort of pet personality quiz developed by James Serpell, an ethologist at the University of Pennsylvania. C-BARQ asks questions like, “What does your dog do when a stranger comes to the door?” to allow owners to objectively characterize 14 aspects of their pet’s personalities, including trainability, attachment, and aggression. Since the survey was developed in 2003, more than 50,000 owners have participated. © 2018 American Association for the Advancement of Science

Keyword: Genes & Behavior; Emotions
Link ID: 25852 - Posted: 01.09.2019

Elizabeth Preston A little blue-and-black fish swims up to a mirror. It maneuvers its body vertically to reflect its belly, along with a brown mark that researchers have placed on its throat. The fish then pivots and dives to strike its throat against the sandy bottom of its tank with a glancing blow. Then it returns to the mirror. Depending on which scientists you ask, this moment represents either a revolution or a red herring. Alex Jordan, an evolutionary biologist at the Max Planck Institute for Ornithology in Germany, thinks this fish — a cleaner wrasse — has just passed a classic test of self-recognition. Scientists have long thought that being able to recognize oneself in a mirror reveals some sort of self-awareness, and perhaps an awareness of others’ perspectives, too. For almost 50 years, they have been using mirrors to test animals for that capacity. After letting an animal get familiar with a mirror, they put a mark someplace on the animal’s body that it can see only in its reflection. If the animal looks in the mirror and then touches or examines the mark on its body, it passes the test. Humans don’t usually reach this milestone until we’re toddlers. Very few other species ever pass the test; those that do are mostly or entirely big-brained mammals such as chimpanzees. And yet as reported in a study that appeared on earlier this year and that is due for imminent publication in PLOS Biology, Jordan and his co-authors observed this seemingly self-aware behavior in a tiny fish. Jordan’s findings have consequently inspired strong feelings in the field. “There are researchers who, it seems, do not want fish to be included in this secret club,” he said. “Because then that means that the [primates] are not so special anymore.” All Rights Reserved © 2019

Keyword: Consciousness; Evolution
Link ID: 25851 - Posted: 01.09.2019

By Kelly Servick In the animal world, monogamy has some clear perks. Living in pairs can give animals some stability and certainty in the constant struggle to reproduce and protect their young—which may be why it has evolved independently in various species. Now, an analysis of gene activity within the brains of frogs, rodents, fish, and birds suggests there may be a pattern common to monogamous creatures. Despite very different brain structures and evolutionary histories, these animals all seem to have developed monogamy by turning on and off some of the same sets of genes. “It is quite surprising,” says Harvard University evolutionary biologist Hopi Hoekstra, who was not involved in the new work. “It suggests that there’s a sort of genomic strategy to becoming monogamous that evolution has repeatedly tapped into.” Evolutionary biologists have proposed various benefits to so-called social monogamy, where mates pair up for at least a breeding season to care for their young and defend their territory. When potential mates are scarce or widely dispersed, for example, forming a single-pair bond can ensure they get to keep reproducing. Neuroscientist Hans Hofmann and evolutionary biologist Rebecca Young at the University of Texas in Austin wanted to explore how the regulation of genes in the brain might have changed when a nonmonogamous species evolved to become monogamous. For example, the complex set of genes that underlie the ability to tolerate the presence of another member of one’s species presumably exists in nonmonogamous animals, but might be activated in different patterns to allow prolonged partnerships in monogamous ones. © 2018 American Association for the Advancement of Science

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 25847 - Posted: 01.08.2019

Katie Brown When polite people talk, they take turns speaking and adjust the timing of their responses on the fly. So do wild macaques, a team of Japanese ethologists reports. Analysis of 20-minute vocal exchanges involving 15 adult female Japanese macaques (Macaca fuscata) revealed that the monkeys altered their conversational pauses depending on how quickly others answered, the researchers report in a study in an upcoming issue of Current Zoology. It’s unclear whether the monkeys were actually talking in any way analogous to how humans converse. While macaques have the vocal equipment to form humanlike words, their brains are unable to transform that vocal potential into human talk (SN Online: 12/19/16). The primates instead communicate in grunts, coos and other similar sounds. But the length of pauses between those grunts and coos closely match the length of pauses in human chats, says coauthor Noriko Katsu of the University of Tokyo. The researchers analyzed 64 vocal exchanges, called bouts, between at least two monkeys that were recorded between April and October 2012 at the Iwatayama Monkey Park in Kyoto, Japan. The team found that the median length of time between the end of one monkey’s calls and the beginning of another’s was 250 milliseconds — similar to the average 200 milliseconds in conversational pause time between humans. That makes the macaques’ gaps between turns in chattering one of the shortest call-and-response pauses yet measured in nonhuman primates. |© Society for Science & the Public 2000 - 2018.

Keyword: Animal Communication; Language
Link ID: 25829 - Posted: 01.01.2019

Ewen Callaway No human has the brain of a Neanderthal — but some have hints of its shape. The brain shape of some people with European ancestry is influenced by Neanderthal DNA acquired through interbreeding tens of thousands of years ago, researchers report on 13 December in Current Biology1. These DNA variants seem to affect the expression of two genes in such a way as to make the brains of some humans slightly less round, and more like the Neanderthals’ elongated brains. “It’s a really subtle shift in the overall roundedness,” says team member Philipp Gunz, a palaeoanthropologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “I don’t think you would see it with your naked eye. These are not people that would look Neanderthal-like.” The Neanderthal DNA variants alter gene expression in brain regions involved in planning, coordination and learning of movements. These faculties are used in speech and language, but there is no indication that the Neanderthal DNA affects cognition in modern humans. Instead, the researchers say, their discovery points to biological changes that might have endowed the human brain with its distinct shape. Earlier this year, Gunz and two colleagues determined that the rounded brain shape of modern humans evolved gradually, reaching its current appearance between 35,000 and 100,000 years ago2. The earliest human fossils from across Africa, dating to around 200,000–300,000 years ago, have large yet elongated brains. “There really is something going on in the brain that changes over time in the Homo sapiens lineage,” says Gunz. © 2018 Springer Nature Publishing AG

Keyword: Evolution; Development of the Brain
Link ID: 25787 - Posted: 12.15.2018

By Ryan Dalton You might be forgiven for having never heard of the NotPetya cyberattack. It didn’t clear out your bank account, or share your social media passwords, or influence an election. But it was one of the most costly and damaging cyberattacks in history, for what it did target: shipping through ports. By the time the engineers at Maersk realized that their computers were infected with a virus, it was too late: worldwide shipping would grind to a halt for days. Imagine a similar situation, in which the target was another port: the synapse, the specialized port of communication between neurons. Much of our ability to learn and remember comes down to the behavior of synapses. What would happen then, if one neuron infected another with malware? Ports and synapses both run on rules, meant to ensure that their cargo can be exchanged not only quickly and reliably, but also adaptably, so that they can quickly adjust to current conditions and demands. This ‘synaptic plasticity’, is fundamental to the ability of animals to learn, and without it we would no more be able to tie our shoes than to remember our own names. Just as shipping rules are determined by treaties and laws, the rules of synaptic plasticity are written into a multitude of genes in our DNA. For example, one gene might be involved in turning up the volume on one side of the synapse, while another gene might ask the other side of the synapse to turn up the gain. Studying the function of these genes has been one of the core approaches to understanding what it is, at the microscopic level, to learn and to remember. © 2018 Scientific American

Keyword: Learning & Memory; Intelligence
Link ID: 25782 - Posted: 12.12.2018

Bruce Bower A nearly complete hominid skeleton known as Little Foot has finally been largely freed from the stony shell in which it was discovered in a South African cave more than 20 years ago. And in the first formal analyses of the fossils, researchers say the 3.67-million-year-old Little Foot belonged to its own species. In four papers posted online at between November 29 and December 5, paleoanthropologist Ronald Clarke of the University of the Witwatersrand in Johannesburg and colleagues assign Little Foot to a previously proposed species, Australopithecus prometheus, that has failed to gain traction among many researchers. Clarke has held that controversial view for more than a decade (SN: 5/2/15, p. 8). He found the first of Little Foot’s remains in a storage box of fossils from a site called Sterkfontein in 1994. Excavations of the rest of the skeleton began in 1997. Many other researchers, however, regard Little Foot as an early member of a hominid species called Australopithecus africanus. Anthropologist Raymond Dart first identified A. africanus in 1924 from an ancient youngster’s skull called the Taung Child. Hundreds of A. africanus fossils have since been found in South African caves, including Sterkfontein. One of those caves, Makapansgat, produced a partial braincase that Dart assigned to A. prometheus in 1948. But Dart dropped that label after 1955, assigning the braincase and another Makapansgat fossil to A. africanus. |© Society for Science & the Public 2000 - 2018.

Keyword: Evolution
Link ID: 25778 - Posted: 12.12.2018

By JoAnna Klein A macaw named Poncho starred in movies like “102 Dalmatians,” “Dr. Doolittle” and “Ace Ventura: Pet Detective” before retiring in England. She recently celebrated her 90th birthday. Alex, an African grey parrot who lived to 31, knew colors, shapes and numbers, and communicated using basic expressions. He could do what toddlers only do after a certain stage of development — know when something is hidden from view. And they’re just two of the many parrots in the world who have surprised us with their intelligence, skills and longevity. “Nature does these experiments for us, and then we have to go and ask, how did this happen?” said Dr. Claudio Mello, a neuroscientist at Oregon Health and Science University. So he and a team of nearly two dozen scientists looked for clues in the genome of the blue-fronted Amazon parrot in Brazil, his home country. After comparing its genome with those of dozens of other birds, the researchers’ findings suggest that evolution may have made parrots something like the humans of the avian world. In some ways, the long-lived feathered friends are as genetically different from other birds as humans are from other primates. Their analysis, published Thursday in Current Biology, also highlights how two very different animals — parrots and humans — can wind up finding similar solutions to problems through evolution. A general rule of life span in birds and other animals is the bigger or heavier you are, the longer you live. A small bird like a finch may live five to eight years, while bigger ones like eagles or cranes can live decades. The blue-fronted Amazon and some other parrots are even more exceptional, in that they can live up to 66 years — in some cases outliving their human companions. © 2018 The New York Times Company

Keyword: Intelligence; Evolution
Link ID: 25764 - Posted: 12.08.2018

One of the animals that's thought to give creatures like apes, dolphins and crows a run for their money when it comes to intelligence is the octopus. For those other animals, there's a pattern to how they evolved to be so smart — they live long, socially complex lives. But that's not the case for octopuses that live solitary lives for the year or two they usually survive. Now scientists think they've figured out how the octopus became so so smart, and it has to do with the loss of their shell through evolution. "Octopuses, unlike many other molluscs, they do not have a protective shell," said Piero Amodio, the lead author on the new study published in the journal Trends in Ecology & Evolution about how cephalopods (octopuses and their relatives) gained their intelligence. "So [octopuses] are very, very vulnerable to many kinds of predators — from fishes to marine mammals to birds — and the idea is that by becoming quite smart, this is a kind of weapon they can use to avoid being eaten." Amodio, a PhD student at the University of Cambridge, told Quirks & Quarks host Bob McDonald that this evolutionary process differs from those that led to intelligence in other groups of vertebrates. Intelligence in other vertebrates is thought to have arisen because they live long and socially complex lives. Building a brain is a metabolically labour intensive process, so it's a big investment for an animal to develop a big brain like in apes, dolphins, and crows — an investment they get a return on when they live a long time. ©2018 CBC/Radio-Canada.

Keyword: Evolution; Intelligence
Link ID: 25763 - Posted: 12.08.2018