Linda Geddes Your dog might follow commands such as “sit”, or become uncontrollably excited at the mention of the word “walkies”, but when it comes to remembering the names of toys and other everyday items, most seem pretty absent-minded. Now a study of six “genius dogs” has advanced our understanding of dogs’ memories, suggesting some of them possess a remarkable grasp of the human language. Hungarian researchers spent more than two years scouring the globe for dogs who could recognise the names of their various toys. Although most can learn commands to some degree, learning the names of items appears to be a very different task, with most dogs unable to master this skill. Max (Hungary), Gaia (Brazil), Nalani (Netherlands), Squall (US), Whisky (Norway), and Rico (Spain) made the cut after proving they knew the names of more than 28 toys, with some knowing more than 100. They were then enlisted to take part in a series of livestreamed experiments known as the Genius Dog Challenge. “These gifted dogs can learn new names of toys in a remarkable speed,” said Dr Claudia Fugazza at Eötvös Loránd University in Budapest, who led the research team. “In our previous study we found that they could learn a new toy name after hearing it only four times. But, with such short exposure, they did not form a long-term memory of it.” To further push the dogs’ limits, their owners were tasked with teaching them the names of six, and then 12 new toys in a single week. © 2021 Guardian News & Media Limited

Keyword: Animal Communication; Language
Link ID: 28023 - Posted: 10.06.2021

By Laura Sanders A personalized brain implant eased the crushing symptoms of a woman’s severe depression, allowing her to once again see the beauty of the world. “It’s like my lens on the world changed,” said Sarah, the research volunteer who requested to be identified by her first name only. The technology, described October 4 in Nature Medicine, brings researchers closer to understanding how to detect and change brain activity in ultraprecise ways (SN: 2/10/19). The device was bespoke; it was built specifically for Sarah’s brain. The details of the new system may not work as a treatment for many other people, says Alik Widge, a psychiatrist and neural engineer at the University of Minnesota in Minneapolis. Still, the research is “a really significant piece of work,” he says, because it points out a way to study how brain activity goes awry in depression. Researchers at the University of California, San Francisco implanted temporary thin wire electrodes into Sarah’s brain. The 36-year-old woman had suffered from severe depression for years. These electrodes allowed researchers to monitor the brain activity that corresponded to Sarah’s depression symptoms — a pattern that the researchers could use as a biomarker, a signpost of trouble to come. In Sarah’s case, a particular sign emerged: a fast brain wave called a gamma wave in her amygdala, a brain structure known to be involved in emotions. With this biomarker in hand, the researchers then figured out where to stimulate the brain to interrupt Sarah’s distressing symptoms. A region called the ventral capsule/ventral striatum, or VC/VS, seemed to be the key. That’s not surprising; previous research suggests the region is involved with feeling good and other emotions. When researchers applied tiny jolts of electrical current to this region, Sarah’s mood improved. © Society for Science & the Public 2000–2021.

Keyword: Depression
Link ID: 28022 - Posted: 10.06.2021

by Peter Hess Mice with a mutated copy of MYT1L, a leading autism candidate gene, have unusually small brains and many other physical and behavioral traits mirroring those seen in people with similar mutations, according to a study published today in Neuron. The mice represent the first model of MYT1L syndrome, a rare genetic condition marked by autism, intellectual disability, attention deficit hyperactivity disorder (ADHD), obesity and microcephaly, or a smaller-than-average head. “Generating a mouse line is always a gamble,” says lead investigator Joseph Dougherty, associate professor of genetics and psychiatry at Washington University in St. Louis, Missouri. “The stars really aligned for us.” MYT1L encodes a transcription factor, a type of protein that influences gene expression. But few studies have explored how mutations in the gene lead to the traits seen in people, partly because there are likely fewer than 100 cases worldwide. Dougherty and his colleagues used CRISPR to engineer mice with a MYT1L mutation that resembles one identified in an autistic person. The mice have neurons that mature earlier than expected, which could help explain the traits seen in people. As the first mouse model of MYT1L mutations, “this is a landmark piece of work, and is certainly promising for fundamental science exploration and as a preclinical model,” says Charis Eng, chair of the Cleveland Clinic’s Genomic Medicine Institute in Ohio, who was not involved in the work. © 2021 Simons Foundation

Keyword: Autism; Development of the Brain
Link ID: 28021 - Posted: 10.06.2021

By Erin Blakemore Methamphetamine overdoses are on the rise, a study published in JAMA Psychiatry says. When researchers from the National Institute on Drug Abuse (NIDA) and the Centers for Disease Control and Prevention analyzed data from 2015 to 2019, they found that meth overdose deaths in the United States had almost tripled. During that time span, meth-related overdoses rose from 5,526 to 15,489. This was accompanied by a 43 percent increase in people reporting meth use. Researchers believe over 2 million adults used meth during the period, up from 1.4 million. They used data from the National Vital Statistics System, which tracks births, deaths and the reasons people die. Then they looked at data from the National Survey on Drug Use and Health, which analyzes a random sample of adults in the United States. Advertisement The study shows stark differences in who uses meth. American Indians and Alaska Natives were the most likely to report methamphetamine-use disorder, meth injection and overall meth use. Black people who don’t inject meth also experienced a sharp rise in meth use, which increased more than tenfold. Gay men had the highest prevalence of meth injection. More than three times the women who reported meth use in previous years said they used the drug between 2015 and 2019. Age was a factor, too. Young adults 18 to 23 showed a fourfold increase in meth use without injection. Overall, the number rose by nearly half for all U.S. adults.

Keyword: Drug Abuse
Link ID: 28020 - Posted: 10.06.2021

Sruthi S. Balakrishnan For nearly two decades, academic and industry researchers working to find ways to slow the progression of Alzheimer’s disease have focused chiefly on the amyloid-β plaques that accumulate among neurons. Dozens of clinical trials have tested drugs designed to remove or reduce these plaques, but successes have been few. Aducanumab, Biogen’s amyloid-attacking antibody drug (brand name Aduhelm) that was approved earlier this year following a long drought in new treatments for Alzheimer’s disease (AD), has been mired in controversy after scientists raised questions about the drug’s efficacy. This lack of progress has prompted many research groups to look instead at non-neuronal cells in the brain, and in particular, at immune cells known as microglia. Vital in both developing and mature brains, these cells help shape neurons, control how they communicate, keep an eye out for pathogenic intruders, and mediate neuroinflammation. This last role has emerged as particularly important as researchers uncover evidence that inflammation is linked to many neurological diseases—including AD—as well as to other conditions associated with aging. Many scientists have been waiting for the pharmaceutical industry to take notice of this link. “We knew all this ten years before, the rest of the world just didn’t pay attention to it,” says Jean Harry, a neurotoxicologist at the National Institute of Environmental Health Sciences in Durham, North Carolina. Key players in driving change have been recent genome-wide association studies (GWAS), which have pointed to AD–associated mutations in genes that are highly expressed in microglia, strengthening the evidence for links between these cells and the disease. “You can’t ignore it anymore,” says Bobbi Fleiss, a microglial neurobiologist at RMIT University in Melbourne, Australia. © 1986–2021 The Scientist.

Keyword: Glia; Neuroimmunology
Link ID: 28019 - Posted: 10.02.2021

By Christina Caron For about 1 in 20 people in the northern half of the United States, cooling temperatures and shorter, darker days may signal the onset of seasonal affective disorder, or SAD, a type of depression that typically arrives in the fall or winter, then goes away in the spring. Unlike mild cases of the “winter blues,” SAD symptoms make it difficult to function. It tends to start with so-called “vegetative symptoms”: an increased appetite and a craving for carbohydrates like french fries or ice cream, the urge to sleep longer hours, difficulty getting up in the morning and feeling wiped out at work. Then, in three to four weeks, “the mood plummets,” said Michael Terman, a professor of clinical psychology at Columbia University and an expert in seasonal affective disorder. Patients with SAD develop major depression, which includes persistent feelings of sadness, withdrawal from friends and family and a loss of interest in activities that were once enjoyable. Researchers don’t yet know why some people develop SAD and others do not, but the disorder is believed to run in families and is more common among women. SAD develops in the fall and winter because shorter daylight hours and less sunlight shift the body’s internal clock, and certain mood-regulating hormones, like serotonin, oscillate with the seasons. The good news is that because SAD is tied to the changing seasons, “you can predict its onset and ward it off,” Dr. Terman said. If you have already started experiencing vegetative symptoms — for example you are sleeping longer and having more difficulty waking up — or if you already know you are susceptible to seasonal affective disorder, experts said it’s best to start implementing preventive measures before major depression sets in. © 2021 The New York Times Company

Keyword: Depression; Biological Rhythms
Link ID: 28018 - Posted: 10.02.2021

By Jackie Rocheleau Elevated blood levels of a specific protein may help scientists predict who has a better chance of bouncing back from a traumatic brain injury. The protein, called neurofilament light or NfL for short, lends structural support to axons, the tendrils that send messages between brain cells. Levels of NfL peak on average at 10 times the typical level 20 days after injury and stay above normal a year later, researchers report September 29 in Science Translational Medicine. The higher the peak NfL blood concentrations after injury, the tougher the recovery for people with TBI six and 12 months later, shows the study of 197 people treated at eight trauma centers across Europe for moderate to severe TBI. Brain scans of 146 participants revealed that their peak NfL concentrations predicted the extent of brain shrinkage after six months, and axon damage at six and 12 months after injury, neurologist Neil Graham of Imperial College London and his colleagues found. These researchers also had a unique opportunity to check that the blood biomarker, which gives indirect clues about the brain injury, actually measured what was happening in the brain. In 18 of the participants that needed brain surgery, researchers sampled the fluid surrounding injured neurons. NfL concentrations there correlated with NfL concentrations in the blood. “The work shows that a new ultrasensitive blood test can be used to accurately diagnose traumatic brain injury,” says Graham. “This blood test can predict quite precisely who’s going to make a good recovery and who’s going to have more difficulties.” © Society for Science & the Public 2000–2021.

Keyword: Brain Injury/Concussion
Link ID: 28017 - Posted: 10.02.2021

Annie Melchor After finishing his PhD in neuroscience in 2016, Thomas Andrillon spent a year road-tripping around Africa and South America with his wife. One evening, on a particularly difficult road in Patagonia, his mind began to wander and he ended up accidentally flipping the car. Luckily, no one was hurt. As locals rushed in to help, they asked Andrillon what had happened. Was there an animal on the road? Had he fallen asleep at the wheel? “I had difficulty explaining that I was just thinking about something else,” he remembers. This experience made him think. What had happened? What was going on in his brain when his mind began to wander? In 2017, Andrillon started his postdoctoral research with neuroscientists Naotsugu Tsuchiya and Joel Pearson at Monash University in Melbourne. Shortly after, Tsuchiya and Andrillon teamed up with philosopher Jennifer Windt, also at Monash, to dive into the neural basis of mind wandering. Initially, Andrillon says, they wanted to know if they could detect mind wandering from facial expressions, recalling how teachers claim to be very good at knowing when their students are not paying attention. So they did a pilot experiment in which they filmed their test subjects performing a tedious, repetitive task. After reviewing the videos, one of Andrillon’s students came to him, concerned. “I think we have a problem,” said the student. “[The subjects] look exhausted.” Sure enough, even though all the study participants were awake, they were obviously struggling to not fall asleep, says Andrillon. It was this observation that gave them the idea to broaden their focus, and start looking at the connection between wavering attention and sleep. © 1986–2021 The Scientist.=

Keyword: Attention; Sleep
Link ID: 28016 - Posted: 10.02.2021

By Sierra Carter Black women who have experienced more racism throughout their lives have stronger brain responses to threat, which may hurt their long-term health, according to a new study I conducted with clinical neuropsychologist Negar Fani and other colleagues. I am part of a research team that for more than 15 years has studied the ways stress related to trauma exposure can affect the mind and body. In our recent study, we took a closer look at a stressor that Black Americans disproportionately face in the United States: racism. My colleagues and I completed research with 55 Black women who reported how much they’d been exposed to traumatic experiences, such as childhood abuse and physical or sexual violence, and to racial discrimination, experiencing unfair treatment due to race or ethnicity. We asked them to focus on a task that required attention while simultaneously looking at stressful images. We used functional MRI to observe their brain activity during that time. We found that Black women who reported more experiences of racial discrimination had more response activity in brain regions that are associated with vigilance and watching out for threat — that is, the middle occipital cortex and ventromedial prefrontal cortex. Their reactions were above and beyond the response caused by traumatic experiences not related to racism. Our research suggests that racism had a traumalike effect on Black women’s health; being regularly attuned to the threat of racism can tax important body-regulation tools and worsen brain health.

Keyword: Stress; Brain Injury/Concussion
Link ID: 28015 - Posted: 10.02.2021

Amanda Heidt Qin Liu studies sneezing for a personal reason: her entire family suffers from seasonal allergies. “Until you experience something chronically, it is really hard to appreciate how disruptive it can be,” says Liu, a neuroscientist at Washington University in St. Louis. And given the role of sneezing in pathogen transmission, a better understanding of the molecular underpinnings of the phenomenon could one day help scientists mitigate or treat infectious diseases. When Liu first started looking into the mechanisms governing sneezing, she found that scientists know surprisingly little about how this process works. While prior research had identified a region in the brains of cats and humans that is active during sneezing, the exact pathways involved in turning a stimulus like pollen or spicy food into a sneeze remained unknown. To study sneezing in more detail, Liu and her team developed a new model by exposing mice to irritants such as histamine and capsaicin—a chemical in spicy peppers—and characterizing the physical properties of their resulting sneezes. Then, focusing on that previously discovered sneeze center, located in the brain’s ventromedial spinal trigeminal nucleus (SpV), Liu attempted to map the neural pathway. SNEEZE TRIGGER: When exposed to allergens such as histamine or chemical irritants such as capsaicin (1), sensory neurons in the noses of mice produce a peptide called neuromedin B (NMB). This signaling molecule binds to neurons in a region of the brainstem known as the ventromedial spinal trigeminal nucleus (SpV), which is known to be active during sneezing (2). These neurons send electrical signals (3) to neurons in another brainstem region called the caudal ventral respiratory group (cVRG), which controls exhalation, thus driving the initiation and propagation of sneezing (4). Ablating the nasal neurons or disrupting NMB signaling led to a significantly reduced sneezing reflex in the mice. WEB | PDF © 1986–2021 The Scientist.

Keyword: Brain imaging; Pain & Touch
Link ID: 28014 - Posted: 10.02.2021

By Sam Roberts Washoe was 10 months old when her foster parents began teaching her to talk, and five months later they were already trumpeting her success. Not only had she learned words; she could also string them together, creating expressions like “water birds” when she saw a pair of swans and “open flower” to gain admittance to a garden. Washoe was a chimpanzee. She had been born in West Africa, probably orphaned when her mother was killed, sold to a dealer, flown to the United States for use of testing by the Air Force and adopted by R. Allen Gardner and his wife, Beatrix. She was raised as if she were a human child. She craved oatmeal with onions and pumpkin pudding. “The object of our research was to learn how much chimps are like humans,” Professor Gardner told Nevada Today, a University of Nevada publication, in 2007. “To measure this accurately, chimps would be needed to be raised as human children, and to do that, we needed to share a common language.” Washoe ultimately learned some 200 words, becoming what researchers said was the first nonhuman to communicate using sign language developed for the deaf. Professor Gardner, an ethologist who, with his wife, raised the chimpanzee for nearly five years, died on Aug. 20 at his ranch near Reno, Nev. He was 91. His death was announced by the University of Nevada, Reno, where he had joined the faculty in 1963 and conducted his research until he retired in 2010. When scientific journals reported in 1967 that Washoe (pronounced WA-sho), named after a county in Nevada, had learned to recognize and use multiple gestures and expressions in sign language, the news electrified the world of psychologists and ethologists who study animal behavior. © 2021 The New York Times Company

Keyword: Language; Evolution
Link ID: 28013 - Posted: 10.02.2021

Katharine Sanderson A large, UK-based study of genetics and autism spectrum disorder (ASD) has been suspended, following criticism that it failed to properly consult the autism community about the goals of the research. Concerns about the study include fears that its data could potentially be misused by other researchers seeking to ‘cure’ or eradicate ASD. The Spectrum 10K study is led by Simon Baron-Cohen, director of the Autism Research Centre (ARC) at the University of Cambridge, UK. The £3-million (US$4-million) project, which is funded by the London-based biomedical funding charity Wellcome, is the largest genetic study of ASD in the United Kingdom. It aims to collect DNA samples, together with information on participants’ mental and physical health, from 10,000 people with autism and their families. This will be used to study the genetic and environmental contributions to ASD, and to co-occurring conditions such as epilepsy and gut-health problems. “If we can understand why these co-occurring conditions are more frequent in autistic people, that could open the door to treatment or management of very distressing symptoms,” says Baron-Cohen. But soon after the study’s high-profile launch on 24 August, people with autism and some ASD researchers expressed concern that it had gone ahead without meaningfully consulting the autism community. Fears about the sharing of genetic data and an alleged failure to properly explain the benefits of the research have been raised by a group called Boycott Spectrum 10K, which is led by people with autism. The group plans to protest outside the ARC premises in Cambridge in October. A separate petition against the study gathered more than 5,000 signatures. © 2021 Springer Nature Limited

Keyword: Autism; Genes & Behavior
Link ID: 28012 - Posted: 09.29.2021

by Giorgia Guglielmi About five years ago, when his younger twin brothers reached their thirties, Giacomo Vivanti started to wonder how the pair, who both have autism, would fare in middle and old age. In particular, he wondered if they might be prone to develop age-related neurological conditions. His brothers didn’t show any signs of ill health or cognitive deterioration, but Vivanti, associate professor of early detection and intervention at the A.J. Drexel Autism Institute in Philadelphia, Pennsylvania, knew that the scientific literature provided few clear answers. “I was pretty shocked to learn that we have such limited knowledge of outcomes as children with autism become adults, and as they age,” Vivanti says. It prompted him to scour four years’ worth of data from Medicaid, the largest healthcare program in the United States, to determine the incidence of neurodegenerative conditions among 30- to 64-year-olds with autism. That group, he and his colleagues reported last month, is about 2.5 times as likely to be diagnosed with early-onset Alzheimer’s or other forms of dementia as the general population. The study is one of a handful that have found higher-than-average rates of neurodegenerative conditions in autistic adults. The risk estimates for Parkinson’s disease in autistic people range from 15 to 20 percent, compared with about 1 percent in the general population. Similarly, the prevalence of dementia is less than 1 percent in non-autistic people but about 4 percent in those with autism. None of these studies offer solid evidence, but their results are strong enough to warrant further investigation, researchers say. © 2021 Simons Foundation

Keyword: Autism; Alzheimers
Link ID: 28011 - Posted: 09.29.2021

James Cusack Being autistic, for me and the 700,000 other autistic people in the UK, often means spending a lot of time inhabiting a world that doesn’t work well for you. This is why it’s vital that the needs and preferences of autistic people are better understood. A trial of a therapy whose findings were published this week attempts to address this issue by trying to ensure the needs of toddlers who may be autistic are recognised. On one hand, the results are exciting, but they are also complex. Complexity is always hard to communicate. The international research study, led by Prof Andrew Whitehouse at the University of Western Australia in Perth, is technically well designed. It partly replicates a previous trial, and has promising results. Of its two main findings, one is exciting for child development. The second is thornier in how it relates to autism diagnoses. Advertisement The therapy used in the trial was an adapted version of one used among children who are not autistic. It focuses on working with parents to understand how a child prefers to play, and supports them to adapt their own behaviour to match their toddler’s natural way of interacting. Play is one of the fundamental building blocks of how children begin to learn how to interact with people and the world around them. From speaking to autistic people and families, we know that developing communication and language skills alongside finding ways to ensure families feel able to support autistic people are top priorities for autism research. Social communication skills make a huge difference in all our lives. They improve our chances of being able to explain our needs, build stronger relationships and find employment: all things that autistic people can find challenging. © 2021 Guardian News & Media Limited

Keyword: Autism
Link ID: 28010 - Posted: 09.29.2021

By Tara Ellison As menopause hit, I found I wasn’t as interested in intimacy as I used to be. Sex started to feel like a box that needed to be checked a couple of times a week, and that was causing problems in my marriage. But it wasn’t just sex. I felt was slowing down in many areas. After hot flashes in my 40s had sent me running to the gynecologist for help, I’d been using bioidentical creams to balance my declining hormones. When, at 51, I confided to a friend that I’d had limited success with what my doctor prescribed, she said that she was thriving on something called hormonal “pellets.” I grilled her about them and then made an appointment with her practitioner, an internal medicine doctor. He ordered extensive lab work, which showed that my testosterone levels were very low, which can happen with aging. The doctor said I had two options: do nothing, which he said would eventually likely lead to loss of muscle, decreased bone density and a host of other health complications. Or up my testosterone. Testosterone therapy for women is a hotly debated subject. Studies suggest that testosterone can heighten libido in women with hypoactive sexual desire disorder (HSDD), at least in the short term. A recent statement by a group of international medical societies involved with women’s health endorsed the use of testosterone therapy in women for HSDD, and specifically excluded pellets and injectables as “not recommended.” It also cautioned there was not enough data to support the use of testosterone therapy for cognitive performance.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 28009 - Posted: 09.29.2021

By Jonathan Lambert Identical siblings are used to sharing a lot with their twin, including their DNA. But new research suggests all identical twins share a common signature of twinhood, not in their DNA, but on it. This signature is part of the epigenome, chemical markers that dot many spots along DNA and influence the activity of genes without altering their sequence. Identical twins everywhere largely share a specific set of these marks that persists from birth to adulthood, researchers report September 28 in Nature Communications. These shared epigenetic tags could be used to identify people who were conceived as identical twins but lost their sibling in the womb or were separated at birth. “This paper is absolutely fascinating,” says Nancy Segal, a developmental psychologist at California State University, Fullerton who has researched twins but wasn’t involved in the study. The research sets the groundwork for scientists to better understand “what might cause a fertilized egg to split and form monozygotic [identical] twins,” she says. Despite humans’ age-old fascination with identical twins, the biological process that generates them, known as monozygotic twinning, “is an enigma,” says Jenny van Dongen, an epigeneticist at Vrije Universiteit Amsterdam. Researchers know that identical twins form after a fertilized egg, called a zygote, somehow splits into two embryos during development. But why this cleavage happens remains unknown, van Dongen says. For the most part, identical twins don’t run in families, and they occur at roughly the same rate worldwide — about 3 to 4 per 1,000 births. With no clear genetic or environmental cause, the prevailing hypothesis is that identical twins arise at random, she says. © Society for Science & the Public 2000–2021.

Keyword: Genes & Behavior; Epigenetics
Link ID: 28008 - Posted: 09.29.2021

By Judith Graham The approval of a controversial new drug for Alzheimer’s disease, Aduhelm, is shining a spotlight on mild cognitive impairment (MCI) — problems with memory, attention, language or other cognitive tasks that exceed changes expected with normal aging. After initially indicating that Aduhelm could be prescribed to anyone with dementia, the Food and Drug Administration now specifies that the prescription drug be given to individuals with MCI or early-stage Alzheimer’s, the groups in which the medication was studied. Yet this narrower recommendation raises questions. What does a diagnosis of MCI mean? Is Aduhelm appropriate for all people with MCI, or only some? And who should decide which patients qualify for treatment: dementia specialists or primary care physicians? Debate surrounds Aduhelm because its effectiveness has not been proved, its cost is high (an estimated $56,000 a year, not including expenses for imaging and monthly infusions), and its potential side effects are significant (41 percent of patients in the drug’s clinical trials experienced brain swelling and bleeding). Furthermore, an FDA advisory committee strongly recommended against Aduhelm’s approval, and Congress is investigating the process leading to the FDA’s decision. Medicare is studying whether it should cover the medication, and Veterans Affairs has declined to do so under most circumstances. Clinical trials for Aduhelm, developed by Biogen, based in Cambridge, Mass., excluded adults over 85, people taking blood thinners, people who had experienced a stroke, and those with cardiovascular disease or impaired kidney or liver function, among other conditions. If those criteria were broadly applied, 85 percent of people with MCI would not qualify for the drug, according to a research letter in the Journal of the American Medical Association.

Keyword: Alzheimers
Link ID: 28007 - Posted: 09.29.2021

By Carl Zimmer Ancient human footprints preserved in the ground across the White Sands National Park in New Mexico are astonishingly old, scientists reported on Thursday, dating back about 23,000 years to the Ice Age. The results, if they hold up to scrutiny, would rejuvenate the scientific debate about how humans first spread across the Americas, implying that they did so at a time when massive glaciers covered much of their path. Researchers who have argued for such an early arrival hailed the new study as firm proof. “I think this is probably the biggest discovery about the peopling of America in a hundred years,” said Ciprian Ardelean, an archaeologist at Autonomous University of Zacatecas in Mexico who was not involved in the work. “I don’t know what gods they prayed to, but this is a dream find.” For decades, many archaeologists have maintained that humans spread across North and South America only at the end of the last ice age. They pointed to the oldest known tools, including spear tips, scrapers and needles, dating back about 13,000 years. The technology was known as Clovis, named for the town of Clovis, N.M., where some of these first instruments came to light. The age of the Clovis tools lined up neatly with the retreat of the glaciers. That alignment bolstered a scenario in which Siberian hunter-gatherers moved into Alaska during the Ice Age, where they lived for generations until ice-free corridors opened and allowed them to expand southward. But starting in the 1970s, some archaeologists began publishing older evidence of humanity’s presence in North America. Last year, Dr. Ardelean and his colleagues published a report of stone tools in a mountain cave in Mexico dating back 26,000 years. © 2021 The New York Times Company

Keyword: Evolution
Link ID: 28006 - Posted: 09.25.2021

By Jonathan Lambert Vampire bats may be bloodthirsty, but that doesn’t mean they can’t share a drink with friends. Fights can erupt among bats over gushing wounds bit into unsuspecting animals. But bats that have bonded while roosting often team up to drink blood away from home, researchers report September 23 in PLOS Biology. Vampire bats (Desmodus rotundus) can form long-term social bonds with each other through grooming, sharing regurgitated blood meals and generally hanging out together at the roost (SN: 10/31/19). But whether these friendships, which occur between both kin and nonkin, extend to the bats’ nightly hunting had been unclear. “They’re flying around out there, but we didn’t know if they were still interacting with each other,” says Gerald Carter, an evolutionary biologist at Ohio State University in Columbus. To find out, Carter and his colleague Simon Ripperger of the Museum für Naturkunde in Berlin, built on previous research that uncovered a colony’s social network using bat backpacks. Tiny computer sensors glued to 50 female bats in Tolé, Panama, continuously registered proximity to other sensors both within the roost and outside, revealing when bats met up while foraging. Two common vampire bats feed on a cow near La Chorrera, Panama. It can take 10 to 40 minutes for a bat to bite a small, diamond-shaped wound into an animal’s flesh, and fights can sometimes break out over access to wounds. But researchers found that bats who are friendly back at the roost likely feed together in the field, potentially saving time and energy. © Society for Science & the Public 2000–2021

Keyword: Evolution
Link ID: 28005 - Posted: 09.25.2021

By Kimberly Hickok Seahorses are some of the most dazzling fish in the sea. They’re also the only group of animals in which the males, not the females, go through pregnancy and give birth. Now, new research finds the male’s brood pouch—which can hold up to 1000 baby seahorses at a time—develops and functions like a human placenta. “Evolution is just mind boggling,” says Camilla Whittington, an evolutionary biologist at the University of Sydney who led the new work. The study is the first to thoroughly examine how males nurture their young brood while they’re still in the pouch, says Mari Kawaguchi, an evolutionary biologist at Sophia University in Tokyo. Kawaguchi, who has studied seahorses for some 2 decades, has long suspected pregnant seahorses develop something resembling a placenta. Now, at last, there’s proof. Male seahorses start their path toward fatherhood with a dance. They twirl together with their chosen female under the water, changing colors and linking tails as they pirouette around a shared holdfast. Next, they align the female’s ovipositor with the male’s pouch opening so the female can deposit her eggs. Once the deed is done, the male gently sways to settle the eggs. Ten days to 6 weeks later, depending on the species, the male spends hours in labor, pumping and thrusting to force hundreds of tiny babies out into the water. There, they drift until they are grown. As for dad, he is ready for another round of courtship within hours after birth. But during pregnancy, males have one goal: Provide the embryos with everything they need, from oxygen to nutrients to antibodies. “One of the biggest challenges that all pregnant parents have is getting oxygen to their embryos and carbon dioxide away from the embryos,” Whittington says. “That’s really what motivated our study–how do those baby seahorses actually breathe, if you will, inside the brood pouch?” © 2021 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Evolution
Link ID: 28004 - Posted: 09.25.2021