Chapter 6. Evolution of the Brain and Behavior

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Links 1 - 20 of 1928

An all-female freshwater fish species called the Amazon molly that inhabits rivers and creeks along the Texas-Mexico border is living proof that sexual reproduction may be vastly overrated. Scientists said on Monday they have deciphered the genome of the Amazon molly, one of the few vertebrate species to rely upon asexual reproduction, and discovered that it had none of the genetic flaws, such as an accumulation of harmful mutations or a lack of genetic diversity, they had expected. They found that the Amazon molly, named after the fierce female warriors of ancient Greek mythology, boasts a hardy genetic makeup that makes it equally fit, or even more so, than fish using sexual reproduction in which both maternal and paternal genes are passed along to offspring. "The Amazon molly is doing quite well," said biologist Manfred Schartl of the University of Wuerzburg in Germany. "Unexpectedly, we did not find the signs of genomic decay as predicted." The fish reproduces using a strategy in which a female's egg cell develops into a baby without being fertilized by a male's sperm cell. But that does not mean the fish does not need some hanky panky. "The Amazon molly female produces clones of itself by duping a male of a closely related species to mate with her. The asexual mode of reproduction termed gynogenesis requires the female to mate with a male but none of the male's genome is passed to the offspring," said geneticist Wesley Warren of the McDonnell Genome Institute at Washington University in St. Louis. ©2018 CBC/Radio-Canada.

Keyword: Sexual Behavior; Evolution
Link ID: 24659 - Posted: 02.14.2018

A mutant species of all-female crayfish taking over the world is not the latest science fiction film but a real-life environmental thriller. A new study has found that marbled crayfish are multiplying rapidly and invading ecosystems across the world. The ten-legged pests are descended from one single female with a mutation allowing it to reproduce without males. These self-cloning ladies are found for sale in North America, despite a warning against keeping them as pets. Sales of the six-inch creature are already banned by the European Union. Procambarus virginalis did not exist three decades ago. Born to a male and female slough crayfish, a species originally from Florida, the original marbled crayfish had an additional set of chromosomes - a mutation that made her distinct from her parents and allowed her to reproduce without having to mate. Now officially a separate species, the marbled crayfish can been found in the wild in Japan, Madagascar, multiple European countries and the US. The new study published in Nature, Ecology and Evolution describes the invasive species as a threat to wild ones, particularly seven native species in Madagascar. "If you have one animal, essentially, three months later, you will have 200 or 300," Dr Wolfgang Stein, one of the researchers, told Canadian public broadcaster CBC. Dr Stein, who is a neurophysiologist at Illinois State University, told the BBC that they compared 11 marbled crayfish, spread through the pet trade to four locations on three continents. He noted that while they all share the DNA of one mother crayfish, there were some differences in "colouring". "The animal sequenced here by us in the US was more blue-ish than the ones from Germany and Madagascar," Dr Stein said. © 2018 BBC.

Keyword: Sexual Behavior; Evolution
Link ID: 24650 - Posted: 02.13.2018

By Karl Gruber A. Fujiwara et al., “First report on the emergency dance of Apis cerana japonica, which induces odorous plant material collection in response to Vespa mandarinia japonica scouting,” Entomol Sci, doi:10.1111/ens.12285, 2017. The Waggle Dance Honeybees are famous for their waggle dances—figure-eight boogies that foragers use to inform nestmates about the locations of food or water. But entomologists were unclear about whether the dances could also be used to help ensure colony safety. Unwelcome Guests Ayumi Fujiwara, a graduate student at the University of Tokyo, and colleagues simulated wasp attacks on hives of the Japanese honeybee (Apis cerana japonica) to test the bees’ response to danger. “Giant wasps attack the nests of honeybees to feed their brood in autumn. As a result, wasps may sometimes annihilate a whole honeybee colony,” she says. Dance Off The researchers found that the bees did use a waggle dance as a warning signal, but only in response to sightings of one wasp species, Vespa mandarinia japonica. “The hive entrance dance informs bees’ nestmates of a specific emergency and of the urgent necessity to collect odorous plant materials as a counterattack strategy,” Fujiwara says. The bees collect stinky plant materials, such as leaves from Nepalese smartweed (Persicaria nepalensis), and smear them at the hive entrance to deter the wasps. Decoding the Moves The information coded in this new waggle dance is not yet completely clear, notes Margaret Couvillon, a biologist and honeybee specialist at Virginia Tech. “What would be interesting to see is if there are any differences in the conveying of directional information in this defensive context versus the regular foraging context,” she says. “Nature tends to be parsimonious in finding solutions, so we might expect that the bees use a similar mechanism in these different situations.” © 1986-2018 The Scientist

Keyword: Animal Communication; Aggression
Link ID: 24640 - Posted: 02.10.2018

By Catherine Offord River-dwelling populations of the Central American fish species Astyanax mexicanus sleep for more than 10 hours each day. But eyeless, cave-dwelling members of the same species barely sleep at all, and show no obvious health or developmental problems as a result. Now, researchers in the U.S. and in France have identified the signaling pathway behind this difference, offering a glimpse into the processes regulating sleep duration in vertebrates. The findings were published yesterday (February 6) in two papers in eLife. In one study, researchers at Florida Atlantic University compared the brains of cave-dwelling A. mexicanus with their surface-living cousins. They found that the number of neurons producing hypocretin—a neuropeptide linked to sleep-disorders such as narcolepsy when dysregulated—was significantly higher in the cave dwellers. What’s more, inhibiting hypocretin signaling genetically or pharmacologically increased cavefish’s sleep duration by several hours, while having minimal effect on surface-living fish. “These findings suggest that differences in hypocretin production may explain variation in sleep between animal species, or even between individual people,” study coauthor Alex Keene of Florida Atlantic University’s Brain Institute says in a statement. “It may also provide important insight into how we might build a brain that does not need to sleep.” © 1986-2018 The Scientist

Keyword: Sleep; Vision
Link ID: 24632 - Posted: 02.08.2018

By NATALIE ANGIER Every night during breeding season, the male túngara frog of Central America will stake out a performance patch in the local pond and spend unbroken hours broadcasting his splendor to the world. The mud-brown frog is barely the size of a shelled pecan, but his call is large and dynamic, a long downward sweep that sounds remarkably like a phaser weapon on “Star Trek,” followed by a brief, twangy, harmonically dense chuck. Unless, that is, a competing male starts calling nearby, in which case the first frog is likely to add two chucks to the tail of his sweep. And should his rival respond likewise, Male A will tack on three chucks. Back and forth they go, call and raise, until the frogs hit their respiratory limit at six to seven rapid-fire chucks. The acoustic one-upfrogship is energetically draining and risks attracting predators like bats. Yet the male frogs have no choice but to keep count of the competition, for the simple reason that female túngaras are doing the same: listening, counting and ultimately mating with the male of maximum chucks. Behind the frog’s surprisingly sophisticated number sense, scientists have found, are specialized cells located in the amphibian midbrain that tally up sound signals and the intervals between them. “The neurons are counting the number of appropriate pulses, and they’re highly selective,” said Gary Rose, a biologist at the University of Utah. If the timing between pulses is off by just a fraction of a second, the neurons don’t fire and the counting process breaks down. “It’s game over,” Dr. Rose said. “Just as in human communication, an inappropriate comment can end the whole conversation.” © 2018 The New York Times Company

Keyword: Attention; Evolution
Link ID: 24623 - Posted: 02.06.2018

By C. CLAIBORNE RAY Q. Does an octopus have a brain? Where is it? And just how smart is an octopus? A. In a sense, an octopus has several brains, collections of neurons that control each arm. A famous 2001 study in the journal Science described how the commands that control one arm’s movement continue even when connections to the walnut-sized central processing system in the head are severed. Since then, more has been found about why the octopus is so much smarter than the average seafood. Even the relatively small central brain of an octopus is the largest among all invertebrates — proportionally, that is. A review article in 2015 in the journal Current Opinion in Neurobiology summarized the complexity of learning processes in the octopus and its remarkable adaptability. Some studies have examined the cephalopod’s ability to discern objects of different sizes, shapes, colors, brightnesses and textures; and its problem-solving, including the ability to navigate mazes and open jars. The creature also displays both short-term and long-term memory and recall over periods of weeks and even months. A possible explanation of the advanced abilities of the octopus lies in its very large genome, decoded in 2015 in a study in the journal Nature. The researchers surmised that the vast expansion of certain gene families in the octopus, and the network of linkages among the genes, could account for the development of its neurological complexity. © 2018 The New York Times Company

Keyword: Evolution; Learning & Memory
Link ID: 24602 - Posted: 02.02.2018

Susan Milius Ready for sketch comedy she’s not. But a 14-year-old killer whale named Wikie has shown promise in mimicking strange sounds, such as a human “hello” — plus some rude noises. Scientists recorded Wikie at her home in Marineland Aquarium in Antibes, France, imitating another killer whale’s loud “raspberry” sounds, as well as a trumpeting elephant and humans saying such words as “one, two, three.” The orca’s efforts were overall “recognizable” as attempted copies, comparative psychologist José Zamorano Abramson of Complutense University of Madrid and colleagues report January 31 in Proceedings of the Royal Society B. Just how close Wikie’s imitations come to the originals depends on whether you’re emphasizing the rhythm or other aspects of sound, Abramson says. Six people judged Wikie’s mimicry ability, and a computer program also rated her skills. She did better at some sounds, like blowing raspberries and saying “hello-hello,” than others, including saying “bye-bye.” Imitating human speech is especially challenging for killer whales. Instead of vocalizing by passing air through their throats, they sound off by forcing air through passageways in the upper parts of their heads. It’s “like speaking with the nose,” Abramson says. The research supports the idea that imitation plays a role in how killer whales develop their elaborate dialects of bleating pulses. Cetaceans are rare among mammals in that, like humans, they learn how to make the sounds their species uses to communicate. © Society for Science & the Public 2000 - 2017

Keyword: Animal Communication; Language
Link ID: 24596 - Posted: 01.31.2018

Robert D. Martin This may be surprising to some: A woman's age is not alone in affecting pregnancy and birth, despite the impression often given. Reviewing Paul Raeburn's book Do Fathers Matter?, Tabitha Powledge wrote: "Everybody knows that older mothers run higher risks of a baby with birth defects — Down syndrome being the most common and best-known. By comparison, hardly anybody knows that the older Dad gets, the riskier it is for him to conceive a child." Partners age together, so a fetus or baby with an older mother will mostly have an older father, too. Logic demands exploration of age effects in both sexes. Though few and far between, such studies do indeed reveal that both men and women contribute. With Down syndrome, age effects for fathers and mothers are roughly balanced. But new data clearly show that, when it comes to inherited defects, fathers actually carry greater risks than mothers. Random changes in DNA — mutations — accumulate four times faster in sperms than in eggs. Charles Darwin and Alfred Russel Wallace realized that variety is not just the spice of life; it is the very essence. Inherited differences between individuals are the raw material for natural selection. And the prime source of natural variation in genes is new mutations. These have been studied intensively, notably regarding rates of change. Yet mutation also has a dark side because it can produce adverse effects along with variety. Hence, the mutation rate has fundamental implications for medical genetics as well as for evolutionary biology. © 2018 npr

Keyword: Sexual Behavior; Evolution
Link ID: 24592 - Posted: 01.31.2018

Ewen Callaway The oldest human fossils ever found outside Africa suggest that Homo sapiens might have spread to the Arabian Peninsula around 180,000 years ago — much earlier than previously thought. The upper jaw and teeth, found in an Israeli cave and reported in Science on 25 January1, pre-date other human fossils from the same region by at least 50,000 years. But scientists say that it is unclear whether the fossils represent a brief incursion or a more-lasting expansion of the species. Researchers originally thought that H. sapiens emerged in East Africa 200,000 years ago then moved out to populate the rest of the world. Until discoveries in the past decade countered that story, scientists thought that a small group left Africa some 60,000 years ago and that signs of earlier travels, including 80,000–120,000 year-old skulls and other remains from Israel discovered in the 1920s and 1930s, were from failed migrations. However, recent discoveries have muddied that simple narrative. Some H. sapiens-like fossils from Morocco that are older than 300,000 years, reported last year2, have raised the possibility that humans evolved earlier and perhaps elsewhere in Africa. Teeth from southern China, described in 20153, hint at long-distance migrations some 120,000 years ago. And genome studies have sown more confusion, with some comparisons of global populations pointing to just one human migration from Africa4,5, and others suggesting multiple waves6. © 2018 Macmillan Publishers Limited,

Keyword: Evolution
Link ID: 24570 - Posted: 01.26.2018

By Bret Stetka Fossil records can tell us a lot about our evolutionary past: what our ancestors looked like, how they walked, what they ate. But what bits of bone don’t typically reveal is why humans evolved the way we did—why, compared with all other known species, we wound up capable of such complex thought, emotion and behavior. A team of researchers has now used a novel technique to form a hypothesis on the origins of our rich cognitive abilities. They did so by profiling the chemicals buzzing around our brains. These compounds, known as neurotransmitters, are the signaling molecules responsible for key brain functions. Their research reveals that in comparison with other higher primates, our brains have unique neurotransmitter profiles that probably resulted in our enhanced cognition. The authors of the new study—a multicenter effort led by Kent State University anthropologists C. Owen Lovejoy and Mary Ann Raghanti and published January 22 in PNAS—began by measuring neurotransmitter levels in brain samples from humans, chimpanzees, gorillas, baboons and monkeys, all of whom had died of natural causes. Specifically, they tested levels in the striatum, a brain region involved in social behaviors and interactions. Compared with the other species tested, humans had markedly increased striatal dopamine activity. Among other functions, dopamine helps drive reward activity and social behaviors. In the striatum in particular it contributes to uniquely human abilities and behaviors like complicated social group formation and, in part, speech and language. © 2018 Scientific American,

Keyword: Evolution
Link ID: 24567 - Posted: 01.25.2018

Bruce Bower Big brains outpaced well-rounded brains in human evolution. Around the time of the origins of our species 300,000 years ago, the brains of Homo sapiens had about the same relatively large size as they do today, new research suggests. But rounder noggins rising well above the forehead — considered a hallmark of human anatomy — didn’t appear until between about 100,000 and 35,000 years ago, say physical anthropologist Simon Neubauer and his colleagues. Using CT scans of ancient and modern human skulls, the researchers created digital brain reconstructions, based on the shape of the inner surface of each skull’s braincase. Human brains gradually evolved from a relatively flatter and elongated shape — more like that of Neandertals’ — to a globe shape thanks to a series of genetic tweaks to brain development early in life, the researchers propose January 24 in Science Advances. A gradual transition to round brains may have stimulated considerable neural reorganization by around 50,000 years ago. That cognitive reworking could have enabled a blossoming of artwork and other forms of symbolic behavior among Stone Age humans, the team suspects. Other researchers have argued, however, that abstract and symbolic thinking flourished even before H. sapiens emerged (SN: 12/27/14, p. 6). Ancient DNA studies indicate that genes involved in brain development changed in H. sapiens following a split from Neandertals more than 600,000 years ago (SN Online: 3/14/16). “Those genetic changes might be responsible for differences in neural wiring and brain growth that led to brain [rounding] in modern humans, but not in Neandertals,” says Neubauer of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. |© Society for Science & the Public 2000 - 2017

Keyword: Evolution
Link ID: 24566 - Posted: 01.25.2018

Lions, elephants, and baboons are matriarchies that are female-centric in different ways, for different reasons. Lion mothers form ‘daycare centres’ to nurse their young and sisters band together to hunt for their families. It’s not the male who’s the bread-winner — it’s the female. Elephants are led by the eldest female who knows all the watering holes and strategies for survival. Her age and memory of how to survive the long dry season is key in a climate plagued by drought. Baboons have a female royal family where, surprisingly, it’s the youngest female who ascends to the throne. Mommy Wildest is an intimate story – the ”days of our lives” of these families, with individual characters whose challenges we follow: the Ol Dikidiki pride of lionesses raising their 11 cubs; Donatella, the elephant grandmother who leads her family to safety from gunshots shielding them from danger, and bay Rijeka, the baboon princess surrounded by her sisters. Mommy Wildest also follows the leading scientists in their field who’ve been asking: Why did these three societies evolve into matriarchies? What can humans learn from them? Dr. Craig Packer IS the lion king. He’s the foremost lion expert in the world and has been studying lions for more than 40 years. In this film, he travels to Maasai Mara to visit one of the richest concentrations of lions left in the world, and to meet the Ol Dikidiki pride. It was Dr. Packer who determined why lionesses bond together in sisterhoods –it’s to defend against roving males who would kill their cubs and take over the pride. By working together, the sisters can defend against the much stronger male. ©2018 CBC/Radio-Canada.

Keyword: Sexual Behavior; Evolution
Link ID: 24544 - Posted: 01.20.2018

Hanneke Meijer Even though I am better with dead birds than with living ones, I do enjoy watching them. Their behaviour is fascinating, and as Jennifer Ackerman points out in her book, birds are a lot more intelligent than we often give them credit for. But what do we know about the evolution of bird intelligence? How did the bird brain evolve, and when did it take on its “birdiness”? The fossil record isn’t particularly well-suited for the preservation of soft tissue such as brains – and behaviour doesn’t fossilise at all. However, some inferences regarding behaviour can be made based on anatomy, something the fossil record is rife with. When we look at the anatomical evidence of bird behaviour in the fossil record (Naish, 2014), it becomes clear that certain types of behaviour we see in modern birds – such as colonial nesting, parental care and plumage display – evolved a long time ago, and are likely dinosaurian in origin. The avian brain itself is a modified version of the basic archosaur brain (archosaurs are the group of reptiles that gave rise to crocodiles and dinosaurs). The archosaur brain, as seen in living crocodiles, is a relatively simple, tube-like structure consisting of the hindbrain, mid-brain and forebrain along a central axis. The bird brain has undergone significant enlargement of the forebrain and has folded along its main axis, resulting in a distinctive shape. Unfortunately, no fossilised bird brain has yet been found, but the shape and size of the inner brain cavity in fossilised skulls provides some information about brain shape and maximal brain dimensions. It should be noted here that the brain cavity is never an exact representation of the brain itself, as a significant portion of the endocranial space can be taken up by blood vessels, other soft tissues and fluid. © 2018 Guardian News and Media Limited

Keyword: Evolution
Link ID: 24539 - Posted: 01.19.2018

James Gorman Humans, chimpanzees, elephants, magpies and bottle-nosed dolphins can recognize themselves in a mirror, according to scientific reports, although as any human past age 50 knows, that first glance in the morning may yield ambiguous results. Not to worry. Scientists are talking about species-wide abilities, not the fact that one’s father or mother makes unpredictable appearances in the looking glass. Mirror self-recognition, at least after noon, is often taken as a measure of a kind of intelligence and self-awareness, although not all scientists agree. And researchers have wondered not only about which species display this ability, but about when it emerges during early development. Children start showing signs of self-recognition at about 12 months at the earliest and chimpanzees at two years old. But dolphins, researchers reported Wednesday, start mugging for the mirror as early as seven months, earlier than humans. Diana Reiss a psychologist at Hunter College, and Rachel Morrison, then a graduate student working with Reiss, studied two young dolphins over three years at the National Aquarium in Baltimore. Dr. Reiss first reported self-recognition in dolphins in 2001 with Lori Marino, now the head of The Kimmela Center for Animal Advocacy. She and Dr. Morrison, now an assistant professor in the psychology department at the University of North Carolina Pembroke collaborated on the study and published their findings in the journal PLoS One. Dr. Reiss said the timing of the emergence of self-recognition is significant, because in human children the ability has been tied to other milestones of physical and social development. Since dolphins develop earlier than humans in those areas, the researchers predicted that dolphins should show self-awareness earlier. Seven months was when Bayley, a female, started showing self-directed behavior, like twirling and taking unusual poses. © 2018 The New York Times Company

Keyword: Consciousness; Evolution
Link ID: 24519 - Posted: 01.11.2018

Laura Sanders If more nerve cells mean more smarts, then dogs beat cats, paws down, a new study on carnivores shows. That harsh reality may shock some friends of felines, but scientists say the real surprises are inside the brains of less popular carnivores. Raccoon brains are packed with nerve cells, for instance, while brown bear brains are sorely lacking. By comparing the numbers of nerve cells, or neurons, among eight species of carnivores (ferret, banded mongoose, raccoon, cat, dog, hyena, lion and brown bear), researchers now have a better understanding of how different-sized brains are built. This neural accounting, described in an upcoming Frontiers in Neuroanatomy paper, may ultimately help reveal how brain features relate to intelligence. For now, the multispecies tally raises more questions than it answers, says zoologist Sarah Benson-Amram of the University of Wyoming in Laramie. “It shows us that there’s a lot more out there that we need to study to really be able to understand the evolution of brain size and how it relates to cognition,” she says. Neuroscientist Suzana Herculano-Houzel of Vanderbilt University in Nashville and colleagues gathered brains from the different species of carnivores. For each animal, the researchers whipped up batches of “brain soup,” tissue dissolved in a detergent. Using a molecule that attaches selectively to neurons in this slurry, researchers could count the number of neurons in each bit of brain real estate. |© Society for Science & the Public 2000 - 2017.

Keyword: Evolution
Link ID: 24430 - Posted: 12.16.2017

Amy Maxmen A study of some of the world’s most obscure marine life suggests that the central nervous system evolved independently several times — not just once, as previously thought1. The invertebrates in question belong to families scattered throughout the animal evolutionary tree, and they display a diversity of central nerve cord architectures. The creatures also activate genes involved with nervous system development in other, well-studied animals — but they often do it in non-neural ways, report the authors of the paper, published on 13 December in Nature. “This puts a stake in the heart of the idea of an ancestor with a central nerve cord,” says Greg Wray, an evolutionary developmental biologist at Duke University in Durham, North Carolina. “That opens up a lot of questions we don’t have answers to — like, if central nerve cords evolved independently in different lineages, why do they have so many similarities?” In 1875, German zoologist Anton Dohrn noted anatomical similarities between the central nerve cord that runs length-wise through the bodies of annelids — a group of invertebrates that includes earthworms — and the nerve cord in the spine of vertebrates. He proposed that the groups’ ancient common ancestor had a nerve cord that ran along its belly-side, as seen in annelids. He also suggested that this cord flipped to the back of the body in a more recent animal that gave rise to all vertebrates. © 2017 Macmillan Publishers Limited,

Keyword: Evolution; Development of the Brain
Link ID: 24424 - Posted: 12.14.2017

By Ferris Jabr Chickens are loquacious creatures, and Kevin Mitchell would know. He oversees the care of about a million of them on Wilcox Farms properties in Washington State and Oregon. Mitchell says the birds have “patterns of speech” that reveal a lot about their well-being. They are usually noisiest in the morning—a robust concert of clucks, chortles and caws. “When I hear that, I know they are pretty healthy and happy,” Mitchell says. In the evenings when they’re preparing to roost, the chickens are much more mellow, cooing softly. When a hen lays an egg she celebrates with a series of staccato clucks, like drumbeats, culminating in a loud “buck-caw!” If chickens detect an aerial predator—say, by spotting the shadow of a hawk or eagle—they produce a short, high-pitched shriek. And they have a distinct warning for terrestrial threats: The repetitive clucking most people associate with chickens is in fact a ground predator alarm call. One morning many years ago Mitchell entered a chicken house and found it oddly calm and quiet. Instead of making the usual ruckus, the birds were murmuring and shuffling lethargically. He soon discovered that an automated lighting system had failed and the lights had not switched off the night before; the chickens were sleep-deprived. If he had only been able to eavesdrop on the flock, he might have known much sooner that something was amiss. Over the past five years, engineers and poultry scientists at The University of Georgia and Georgia Institute of Technology have been collaborating to help farmers like Mitchell make better use of the information latent in chicken chatter. © 2017 Scientific American

Keyword: Animal Communication; Language
Link ID: 24415 - Posted: 12.11.2017

By Catherine Offord Mantis shrimps are not the easiest animals to work with, as neuroanatomist Nicholas Strausfeld knows firsthand. Not least, there’s the challenge of capturing the crustaceans in the wild. Also known as stomatopods, mantis shrimps live in burrows in shallow seawater and have earned the descriptive nickname “thumb splitters,” thanks to their tendency to use their sharp, powerful claws to slash at prey and pursuers. “At low tide, you wade around and you try and catch these things,” says Strausfeld, who has plenty of experience chasing after the purple-spotted mantis shrimp (Gonodactylus smithii) with a small handheld net in the tropical waters around Lizard Island, Australia. “They’re incredibly fast—it’s very difficult.” For Strausfeld and other neurobiologists, however, all the trouble is well worth it, as these feisty little marine predators are yielding unique insight into the evolution of the arthropods—the most species-rich animal phylum on the planet, containing around 85 percent of all described animal species. “We knew [these shrimps] were very interesting,” says neuroanatomist Gabriella Wolff, previously a PhD student in Strausfeld’s lab at the University of Arizona and now a research associate at the University of Washington in Seattle. In addition to a complex visual system that receives inputs from independently moving eyes, “mantis shrimps have very advanced behaviors that we haven’t necessarily seen in other crustaceans so far.” Research has also suggested they are sophisticated navigators, regularly finding their way home from distant feeding sites. Plus, they recognize other individual mantis shrimps, and remember whether their interactions were confrontational or not. © 1986-2017 The Scientist

Keyword: Learning & Memory; Evolution
Link ID: 24414 - Posted: 12.11.2017

By John Horgan What’s the difference between science and philosophy? Scientists address questions that can in principle be answered by means of objective, empirical investigation. Philosophers wrestle with questions that cannot be empirically resolved and hence remain matters of taste, not truth. Here is a classic philosophical question: What creatures and/or things are capable of consciousness? That is, who (and “who” is the right term, even if you’re talking about a jellyfish or sexbot) belongs to the Consciousness Club? This question animated “Animal Consciousness,” a conference I attended at New York University last month. It should have been called “Animal Consciousness?” or “Animal ‘Consciousness’” to reflect the uncertainty pervading the two-day meeting. Speakers disagreed over when and how consciousness evolved and what is required for it to occur. A nervous system? Brain? Complex responses to the environment? The ability to learn and adapt to new circumstances? And if we suspect that something is sentient, and hence capable of suffering, should we grant it rights? In my last post, I focused on the debate over whether fish can suffer. Scholars also considered the sentience of dogs, lampreys, wasps, spiders, crustaceans and other species. Speakers presented evidence that creatures quite unlike us are capable of complex cognition. Biologist Andrew Barron argued that bees, in spite of their minuscule brains, are not mindless automatons. Their capacity for learning rivals that of mammals. When harmed, bees stop eating and foraging as if they were depressed. Bees, Barron concludes, are conscious. © 2017 Scientific American

Keyword: Consciousness; Evolution
Link ID: 24394 - Posted: 12.05.2017

By Julie Hecht Dog lovers may find it obvious that dogs pick up on our emotions. Attending to our emotional expression—in our faces, behavior, or even smell—would help them live intimately by our side. "Dogs get us," we say. End of story. But what about their side of the story? If dogs attend to our emotions—particularly those we wear on our faces—how might dogs feel when they see our different emotions? An answer to this question arose almost by accident. In 2015, Corsin Müller and colleagues at the University of Veterinary Medicine, Vienna published a study that sought to determine whether dogs can discriminate happy and angry expression in human faces, as opposed to relying on other cues (their finding: yes, dogs can get this information from our faces alone). But because of the study design, the researchers could also peer into how dogs might feel about our emotions. In the study, pet dogs saw images of happy or angry human faces on a computer screen. To get a treat, the dogs had to approach and nose-touch a particular image on the screen. These are dogs. They can do this. Nose-touch for a treat? Yes please. A fabulous dog named Michel will now demonstrate: But when viewing the angry faces, the researchers noticed something odd. Dog performance was affected by whether they saw happy or angry expressions. During the initial training, dogs seeing the angry expression took longer to learn to approach and nose-touch the image for a treat than dogs who saw the happy expression. In other words, dogs were less inclined to approach and nose-touch angry faces, even though doing so would yield a treat. "Why would I approach an angry person? That makes no sense," a dog might think. Through past experiences with people, dogs could come to view the angry expression as aversive. The researchers suggest that dogs "had to overcome their natural tendency to move away from aversive (or threatening) stimuli…" © 2017 Scientific American

Keyword: Emotions; Evolution
Link ID: 24388 - Posted: 12.04.2017