Links for Keyword: Sexual Behavior

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A line of elephants trundles across a dusty landscape in northern Botswana, ears flapping and trunks occasionally brushing the ground. As they pass a motion-activated camera hidden in low shrubbery, photos record the presence of each elephant. What's special about this group? It's only males. Female elephants are known to form tight family groups led by experienced matriarchs. Males were long assumed to be loners, because they leave their mother's herd when they reach 10 to 20 years of age. A new study shows that teenage males aren't anti-social after all. Younger male elephants were seen tagging along behind older males as they travel from place to place. It's more evidence in an emerging body of research that shows older males — like their female counterparts — play an important role in elephants' complex society. For the study published Thursday in the journal Scientific Reports, researchers analyzed photos of 1,264 sightings of male African savannah elephants travelling toward the Boteti River in 2017 and 2018. They found that younger males seldom travelled alone and older males most often led groups of mixed ages. "Mature male elephants often take a position at the front of the line when they are leading the group" to streams or seasonal grazing grounds, said Diana Reiss, director of the Animal Behavior and Conservation Program at Hunter College, who was not involved in the new study. "In human societies, grandparents are valued because they make really important contributions — helping with childcare and passing down knowledge gained over decades," she said. "We're now learning this pattern is also true for some other long-lived mammals, including dolphins, whales and elephants." Photos of 1,264 sightings of male African savannah elephants travelling toward the Boteti River in 2017 and 2018 showed that younger males seldom travelled alone and older males most often led groups of mixed ages. (Connie Allen) ©2020 CBC/Radio-Canada

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 11: Emotions, Aggression, and Stress
Link ID: 27452 - Posted: 09.05.2020

For Armin Raznahan, publishing research on sex differences is a fraught proposition. Now chief of the section on developmental neurogenomics at the National Institutes of Health, Raznahan learned early that searching for dissimilarities between men’s and women’s brains can have unintended effects. “I got my fingers burned when I first started,” Raznahan says. As a PhD student, he published a study that examined structural differences between men’s and women’s brains and how they changed with age. “We observed a particular pattern, and we were very cautious about just describing it, as one should be, not jumping to functional interpretations,” he says. Despite his efforts, The Wall Street Journal soon published an article that cited his study in a defense of single-sex schooling, under the assumption that boys and girls must learn in distinct ways because their brain anatomy is slightly different. “That really threw me,” he says. “The experience has stayed with me.” Nevertheless, Raznahan has continued to study sex differences, in the hope that they could help us better understand neurodevelopmental disorders. He focuses on people with sex chromosome aneuploidy, or any variation other than XX (typically female) and XY (typically male). People with genetic variations (such as XXY) have an inflated risk of autism spectrum disorder, ADHD, and anxiety, among other ailments. Raznahan’s hope is that uncovering if and how men’s and women’s brains differ—for example, in the sizes of regions or the strengths of the connections among them—could help us figure out why people with aneuploidy are more likely to experience neurodevelopmental and psychiatric concerns. Solving this puzzle could be a step toward unlocking the perplexing mystery of psychiatric illness. © 2020 Condé Nast

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 1: Cells and Structures: The Anatomy of the Nervous System
Link ID: 27451 - Posted: 09.05.2020

By Apoorva Mandavilli The coronavirus may infect anyone, young or old, but older men are up to twice as likely to become severely sick and to die as women of the same age. Why? The first study to look at immune response by sex has turned up a clue: Men produce a weaker immune response to the virus than do women, the researchers concluded. The findings, published on Wednesday in Nature, suggest that men, particularly those over age 60, may need to depend more on vaccines to protect against the infection. “Natural infection is clearly failing” to spark adequate immune responses in men, said Akiko Iwasaki, an immunologist at Yale University who led the work. The results are consistent with what’s known about sex differences following various challenges to the immune system. Women mount faster and stronger immune responses, perhaps because their bodies are rigged to fight pathogens that threaten unborn or newborn children. But over time, an immune system in a constant state of high alert can be harmful. Most autoimmune diseases — characterized by an overly strong immune response — are much more prevalent in women than in men, for example. “We are looking at two sides of the same coin,” said Dr. Marcus Altfeld, an immunologist at the Heinrich Pette Institute and at the University Medical Center Hamburg-Eppendorf in Germany. The findings underscore the need for companies pursing coronavirus vaccines to parse their data by sex and may influence decisions about dosing, Dr. Altfeld and other experts said. © 2020 The New York Times Company

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 11: Emotions, Aggression, and Stress
Link ID: 27435 - Posted: 08.26.2020

By Gillian R. Brassil and Jeré Longman A restrictive Idaho law — temporarily blocked by a federal judge Monday night — has amplified a charged debate about who should be allowed to compete in women’s sports, as transgender athletes have become increasingly accepted on the playing field while still facing strong resistance from some competitors and lawmakers. While scientific and societal views of sex and gender identity have changed significantly in recent decades, a vexing question persists regarding athletes who transition from male to female: how to balance inclusivity, competitive fairness and safety. There are no uniform guidelines — in fact the existing rules that govern sports often conflict — to determine the eligibility of transgender women and girls (policy battles have so far primarily centered on regulating women’s sports). And there is scant research on elite transgender athletes to guide sports officials as they attempt to provide equitable access to sports while reconciling any residual physiological advantages that may carry on from puberty. Dr. Eric Vilain, a geneticist specializing in sexual development who has advised the N.C.A.A. and the International Olympic Committee on policies for transgender athletes, said that sports leaders were confronted with “two almost irreconcilable positions” in setting eligibility standards — one relying on an athlete’s declared gender and the other on biological litmus tests. Politics, too, have entered the debate in a divided United States. While transgender people have broadly been more accepted across the country, the Trump administration and some states have sought to roll back protections for transgender people in health care, the military and other areas of civil rights, fueling a rise in hate crimes, according to the Human Rights Campaign. In March, Idaho became the first state to bar transgender girls and women from participating in women’s sports. © 2020 The New York Times Company

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 5: The Sensorimotor System
Link ID: 27426 - Posted: 08.20.2020

By Hannah Thomasy Some 2 percent of men in the U.S. identify as bisexual. But, for decades, some sexuality researchers have questioned whether true bisexual orientation exists in men. In 2005, J. Michael Bailey, a sexuality researcher at Northwestern University, and two colleagues showed men who identify as bisexual brief pornographic clips featuring men or women, while measuring their subjects’ self-reported arousal and change in penis circumference. The results, when compared to men who identified as straight or gay, led them to conclude that the men identifying as bisexual did not actually have “strong genital arousal to both male and female sexual stimuli.” This was in contrast to work on sexual arousal in women, which showed that they — whether identifying as straight or gay — were physically aroused by both male and female stimuli. A New York Times headline covering Bailey’s 2005 study on men declared: “Straight, Gay, or Lying? Bisexuality Revisited.” But the paper also spurred more research into the subject — some of which has now led Bailey to revise his conclusions. In a paper published last month in the Proceedings of the National Academy of Sciences (PNAS), Bailey and 12 colleagues reanalyzed data from eight previously published studies of bisexual-identified men, including the 2005 paper. The new review finds that men who reported attraction to both men and women do in fact show genital arousal towards both male and female stimuli. The data, the authors conclude, offers “robust evidence for bisexual orientation among men.” The PNAS study has drawn positive coverage and received praise from some activists, who see it as valuable confirmation for an often-marginalized sexual identity. But it has also received backlash from other scientists and many bisexual people, some of whom argue that in attempting to prove, based on genital arousal, that bisexuality exists, researchers are discounting bisexual people’s lived experiences. It has also reignited a broader debate over the ethics of human sexuality research — and about what role, if any, scientists should play in validating the experiences of queer people.

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 27422 - Posted: 08.18.2020

A scientific analysis of more than 2,000 brain scans found evidence for highly reproducible sex differences in the volume of certain regions in the human brain. This pattern of sex-based differences in brain volume corresponds with patterns of sex-chromosome gene expression observed in postmortem samples from the brain’s cortex, suggesting that sex chromosomes may play a role in the development or maintenance of sex differences in brain anatomy. The study, led by researchers at the National Institute of Mental Health (NIMH), part of the National Institutes of Health, is published in Proceedings of the National Academy of Sciences. “Developing a clearer understanding of sex differences in human brain organization has great importance for how we think about well-established sex differences in cognition, behavior, and risk for psychiatric illness. We were inspired by new findings on sex differences in animal models and wanted to try to close the gap between these animal data and our models of sex differences in the human brain,” said Armin Raznahan, M.D., Ph.D., study co-author and chief of the NIMH Section on Developmental Neurogenomics. Researchers have long observed consistent sex-based differences in subcortical brain structures in mice. Some studies have suggested these anatomical differences are largely due to the effects of sex hormones, lending weight to a “gonad-centric” explanation for sex-based differences in brain development. However, more recent mouse studies have revealed consistent sex differences in cortical structures, as well, and gene-expression data suggest that sex chromosomes may play a role in shaping these anatomical sex differences. Although the mouse brain shares many similarities with the human brain, it is not clear whether these key findings in mice also apply to humans.

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 4: Development of the Brain
Link ID: 27377 - Posted: 07.21.2020

Ruairi J MacKenzie Research into developing treatments for psychiatric illness is missing out vital data from female animals, producing drugs that aren’t optimized for women and contributing to the failure of clinical trials, said a panel of neuroscientists today at FENS Virtual Forum of Neuroscience. In a press conference, Professor Christina Dalla from the National and Kapodistrian University of Athens, Dr Debra Bangasser from Temple University and Professor Mohammed Milad at New York University Grossman School of Medicine spoke of the impacts of the inequitable use of female animals on their research areas. Dalla reviewed the targeting of the hypothalamic–pituitary–adrenal (HPA) axis using antidepressants. The HPA axis is a major neuroendocrine system that regulates responses to stress and many other bodily processes. Dysfunctions in the HPA axis have long thought to be a factor in the onset of depression, but drugs targeting this axis have roundly failed in clinical trials. Dalla proposed that this failure may partly be the result of pre-clinical studies using male animals, followed by clinical trials that often recruit more women than men. Bangasser and Milad respectively showed how responses to stress and fear also vary between male and female mice. The Forum, held online for the first time, has extensively addressed the representation of women in the field in its program, opening with a Mini-Conference led by the Cajal Club that celebrated the impact of women in the development of neuroscience.

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 27376 - Posted: 07.21.2020

By Elizabeth Preston A clown fish uses his fins to fan water across a glistening mass of eggs, keeping them aerated. A silver arowana scoops up his fertilized eggs with his mouth and holds them gently for two months, until a host of miniature adults swims free from his jaws. A seahorse drifts through coral, his belly pouch swollen with unborn young. Most fish are uninvolved parents. They dump their eggs and sperm, then swim off and let nature take its course. But some species of fish take their parental duties more seriously — and among them, the majority of caring parents are dads. Care from mothers, or from both parents at once, is much less common. In a study published last fall in Evolution, researchers found evidence that paternal care, the system in which dads are the sole caretakers, has evolved dozens of times in fish. These fish aren’t exactly helicopter dads. Their most common parenting style is simply guarding eggs after they’re fertilized. “Some people are surprised this is considered care,” said Frieda Benun Sutton, an evolutionary biologist at the City University of New York. But it does count. To learn more about why this type of care in fish usually comes from dads, Dr. Benun Sutton and her co-author, Anthony Wilson, of Brooklyn College, took a deep dive into the family history of fish parents. They started with an evolutionary tree, built by other researchers in 2017 using genetic data, that shows how almost 2,000 fish species are related. Then they mapped onto the tree all the information they could find about parental care in those species: Were young cared for by fathers, mothers, both or nobody? They also added other factors including the size and number of each fish’s eggs and how they’re fertilized. The completed tree showed that care by fathers is no evolutionary accident: It has arisen at least 30 separate times. Hundreds of the species in this sample have absent mothers and caring fathers. But why? © 2020 The New York Times Company

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 27316 - Posted: 06.22.2020

By Bethany Brookshire Biomedical science has historically been a male-dominated world — not just for the scientists, but also for their research subjects. Even most lab mice were male (SN: 6/18/19). But now, a new study shows that researchers are starting to include more females — from mice to humans — in their work. In 2019, 49 percent of articles surveyed in biomedical science used both male and female subjects, almost twice as many as a decade before, according to findings published June 9 in eLife. A study of articles published in 2009 across 10 biomedical disciplines showed a dismal picture. Only 28 percent of 841 research studies included both males and female subjects. The results were published in 2011 in Neuroscience and Biobehavioral Reviews. The scientific world took note. In 2016, the U.S. National Institutes of Health instituted the Sex as a Biological Variable policy in an effort to correct the imbalance. Scientists had to use both males and females in NIH-funded research unless they could present a “strong justification” otherwise. Annaliese Beery, a neuroscientist at Smith College in Northhampton, Mass., conducted the original study showing the extent of sex bias in research. In 2019, she and Nicole Woitowich, a chemist at Northwestern University in Evanston, Ill., wanted to see if sex bias was still as strong as it was in 2009. Have things improved? After scanning another 720 articles across nine of the 10 original disciplines, the researchers have shown that yes, they have, with nearly half of all journal articles including both males and females. Behavioral research was the most inclusive, with both sexes in 81 percent of studies. Overall, six out of nine fields surveyed showed a significant increase in studies that included both sexes. © Society for Science & the Public 2000–2020

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 27297 - Posted: 06.10.2020

By Yasmin Anwar, Media Relations Stephen Glickman, a pioneer in behavioral endocrinology and founder of the world’s first colony of captive spotted hyenas — he raised generations of them in a UC Berkeley research facility — died at his home in Berkeley on May 22 from pancreatic cancer. He was 87. A professor emeritus of psychology and of integrative biology, whose lifelong bond with animals began during his boyhood near the Bronx Zoo in New York, Glickman joined the UC Berkeley faculty in 1968. Over the next five decades, he conducted studies of creatures great and small, authoring more than 100 research papers. His sharp intellect, warm wit and overall lovability engaged peers and protégés in scientific and social justice pursuits, colleagues said. “Steve was a giant in the field of animal behavior,” said UC Berkeley psychology chair Ann Kring. “He studied a wide variety of species in the wild, at the zoo and, perhaps most famously, at the field station where he conducted work with hyenas for more than 30 years.” Glickman’s standout legacy is his ardent stewardship of a colony of spotted hyenas at UC Berkeley’s Field Station for the Study of Behavior, Ecology and Reproduction. The hyena compound in the Berkeley hills, above the campus, closed in 2014 when funding dried up, but not before yielding seminal discoveries about endocrinology, fertility and other medical conditions that affect humans. Hormone-driven matriarchy By studying female hyenas, who use a long, phallic clitoris, instead of a vagina, for mating and giving birth, Glickman and fellow researchers found that high levels of androgens produced in their ovaries masculinized their sex organs and boosted their aggression and dominance in the pack. Copyright © 2020 UC Regents; all rights reserved

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 8: Hormones and Sex
Link ID: 27292 - Posted: 06.09.2020

by Marcus A. Banks Brain structures differ in volume depending on a person’s social environment and socioeconomic status, and between men and women, according to a new analysis1. The findings could help explain differences seen in the brains of autistic women and men, many of whom find social communication challenging. Researchers analyzed brain scans from about 10,000 people enrolled in the UK Biobank, a large-scale initiative to understand health trends in the United Kingdom. The participants were 55 years old, on average. They completed surveys, answering questions about their income level, satisfaction with friends and family, participation in social activities and feelings of loneliness. The researchers found that associations between the survey responses and the volume of brain regions linked to social contact differ by sex. For example, women who live with two or more people have a larger amygdala — a brain region involved in decision-making and emotional responses — than do women from smaller households. By contrast, household size has little effect on the size variation of amygdalae among men. The study appeared 18 March in Science Advances. The scans also showed that men who say they lack social support from siblings and friends tend to have a larger nucleus accumbens, part of the brain’s reward circuitry, than men who reported having more social support. The researchers did not see this difference in women. Other differences between men and women appeared in networks involving multiple brain regions, such as those involved with visual processing. © 2020 Simons Foundation

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 1: Cells and Structures: The Anatomy of the Nervous System
Link ID: 27260 - Posted: 05.21.2020

Dana Najjar The old riddle, “Which came first, the chicken or the egg?” is relatively easy to answer as a question about the evolution of birth in animals. Egg laying almost certainly came before live birth; the armored fish that inhabited the oceans half a billion years ago and were ancestral to all land vertebrates seem to have laid eggs. But the rest of the story is far from straightforward. Over millennia of evolution, nature has come up with only two ways for a newborn animal to come into the world. Either its mother lays it in an egg, where it can continue to grow before hatching, or it stays inside its mother until emerging as a more fully formed squirming newborn. “We have this really fundamental split,” said Camilla Whittington, a biologist at the University of Sydney. Is there some primordial reason for this strict reproductive dichotomy between egg laying (oviparity) and live birth (viviparity)? When and why did live birth evolve? These are just some of the questions that new research — including studies of a remarkable lizard that can lay eggs and bear live young at the same time — is exploring, all the while underscoring the enormous complexity and variability of sexual reproduction. Early female animals laid eggs in the sense that they released their ova into the world, often thousands at a time. Sperm released by males then fertilized some of these eggs in a hit-or-miss fashion, and the resulting embryos took their chances on surviving in the hostile world until they hatched. Many creatures, particularly small, simple ones, still reproduce this way. All Rights Reserved © 2020

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 27257 - Posted: 05.20.2020

By Kim Severson In the 1980s, when marriage and adopting children seemed impossible dreams for gay men, the psychoanalyst Richard C. Friedman became their champion. His 1988 book, “Male Homosexuality: A Contemporary Psychoanalytic Perspective,” showed that sexual orientation was largely biological and presented a case that helped undermine the belief held by most Freudian analysts at the time that homosexuality was a pathology that could somehow be cured. “I felt an ethical obligation to find the reasons for anti-homosexual prejudice,” he once told an interviewer. His wife, Susan Matorin, a clinical social worker at the Weill Medical College of Cornell, put it more plainly: “Straight people had the same personality issues, and they got away with murder, but gay people were stigmatized, and he didn’t think that was right.” Dr. Friedman’s motivation wasn’t political. “He very much felt like you followed the science, and it didn’t matter what the political backdrop was,” his son, Jeremiah, a screenwriter in Los Angeles, said in a phone interview. Although the American Psychiatric Association, the dominant mental health organization in the United States, changed its diagnostic manual in 1973 and stopped classifying homosexuality as an illness, psychoanalysts continued to describe homosexuality as a perversion, and many believed it could be cured. Dr. Friedman, using studies of identical twins and theories of developmental psychology, made a scholarly rather than ideological case that biology rather than upbringing played a significant role in sexual orientation. It was a direct challenge to popular Freudian theories and thrust him into the center of debates among the more established heavyweights of psychoanalysis. It led to a model in which analyst and patient simply assumed that homosexuality was intrinsic, said Jack Drescher, a professor of psychiatry at Columbia University who knew Dr. Friedman and would later offer his own critiques of Dr. Friedman’s theory as new approaches to working with gay and lesbian patients emerged. © 2020 The New York Times Company

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 27229 - Posted: 05.05.2020

Christie Wilcox Sex might be biology’s most difficult enigma. The downsides of relying on sex to reproduce are undeniable: It takes two individuals, each of whom gets to pass on only part of their genome. Because these individuals generally have to get fairly intimate, they make themselves vulnerable to physical harm or infections from their partner. Asexual reproduction, or self-cloning, has none of these disadvantages. Clones can be made anywhere and anytime, and they receive the full complement of an individual’s genes. Yet despite all its benefits, asexual reproduction is the exception, not the norm, among organisms that have compartmentalized cells (eukaryotes). In plants, for example — which are somewhat known for their genetic flexibility — less than 1% of species are thought to reproduce asexually often. Among animals, only one out of every thousand known species is exclusively asexual. For centuries, biologists have pondered this apparent paradox. In 1932, the geneticist Hermann Muller, whose work on radiation-induced mutations would eventually garner a Nobel Prize, believed he had the answer. “Genetics has finally solved the age-old problem of the reason for the existence (i.e., the function) of sexuality and sex,” he boasted in The American Naturalist. He went on to explain, “Sexuality, through recombination, is a means for making the fullest use of the possibilities of gene mutations.” All Rights Reserved © 2020

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 27210 - Posted: 04.24.2020

By Elizabeth Pennisi Ring-tailed lemurs have a peculiar habit of shaking their tails at potential rivals. New research shows that during the breeding season, a male’s trembling tail may instead be whisking sexy odors toward potential mates. The work is still preliminary, but chemical analyses have revealed the odor is a mixture of three chemicals that seem to pique a female’s interest. The new work “calls attention to the often underappreciated fact” that odors play an important role in primate societies, says Peter Kappeler, a primatologist at the University of Göttingen. Insects often use behavior-altering odors called pheromones to attract mates. So do mice. But biochemist Kazushige Touhara at the University of Tokyo wanted to know whether primates—including humans—use them as well. Some researchers say yes, but the existence of such “sex attractants” remains controversial. Ring-tailed lemurs (Lemur catta), named for their fluffy gray and black tails, are unusual among their fellow primates. Males have glands on their wrists that produce chemicals that quickly vaporize when exposed to air—similar to pheromones. They rub their wrists on their tails to transfer the odors before they vaporize, then shake their tails to broadcast the scent. For most of the year, these lemurs make bitter, leathery smelling chemicals used to keep other males at bay. But during the breeding season, they instead emit a sweet scent, Touhara says. He and his colleagues collected these secretions from the wrist glands with a tiny pipette and analyzed the chemical components. © 2020 American Association for the Advancement of Science.

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 9: Hearing, Balance, Taste, and Smell
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 27203 - Posted: 04.17.2020

By John Pickrell Joseph Schubert spends hours at a time lying in the dirt of the Australian outback watching for tiny flickers in the sparse, ground-hugging foliage. The 22-year-old arachnologist is searching for flea-sized peacock spiders, and he admits, he’s a little obsessed. But it wasn’t always so. Schubert grew up fearing spiders, with parents who were “absolutely terrified” of the eight-legged crawlers. “I was taught that every single spider in the house was going to kill me, and we should squish it and get rid of it,” he says. Then Schubert stumbled across some photographs of Australia’s endemic peacock spiders, a group named for the adult males’ vivid coloring and flamboyant dance moves aimed at wooing a mate (SN: 9/9/16; SN: 12/8/15). And he was hooked. “They raise their third pair of legs and dance around and show off like they are the most amazing animals on the planet, which in my eyes they are.” He decided to pursue a career in arachnology. And despite not quite having completed his undergraduate degree in biology, he’s begun working part time at Museums Victoria in Melbourne, and has already made a mark. Of the 86 known peacock spider species — each just 2.5 to 6 millimeters in length — 12 have been described by Schubert, including seven named in the March 27 Zootaxa. Those seven were found at a range of sites across Australia, including the barren dunes and shrublands of Victoria state’s Little Desert and the red rocks and arid outback gorges of Kalbarri National Park, north of Perth. © Society for Science & the Public 2000–2020

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 27202 - Posted: 04.17.2020

By Elizabeth Pennisi Males resort to all sorts of desperate measures when fertile females are scarce, including banding together to guard a potential mate. Now, researchers have discovered that such bands of bottlenose dolphins may coordinate their actions with unique “popping” calls—the first evidence that animals other than humans can synchronize themselves using vocal signals. Humans often use vocal signals to coordinate actions, like marching and dancing, that reinforce unity and intimidate outside groups. The synchronized displays of other animals—like fireflies that light up at the same time—are thought to be competitive, showing off which male is the sexiest, rather than cooperative. In Shark Bay, off the coast Western Australia 800 kilometers north of Perth, groups of up to 14 male dolphins form lifelong alliances. Together, subsets of three keep close tabs on potential female mates, swimming, turning, and surfacing in unison to guard and herd them—one female at a time. Scientists watching this behavior noticed these males often emit a unique “popping” call, making series of two to 49 very short sounds, 10 per second, over and over. e dolphins popping The scientists dragged four underwater microphones behind a motorboat and recorded 172 instances in which multiple males were “popping” together (above). When the males pop alone, their timing and tempo varies. But when they pop together, they do it at the same time and at the same rate, suggesting they are using the sounds to enhance their cooperation, the team reports today in the Proceedings of the Royal Society B. This synchronized popping may be a threat, as it tends to make the female dolphin move closer to her male guards. But more importantly, the researchers say, it may help reinforce that the males need to act—and talk—as one to ensure they get their gal. © 2020 American Association for the Advancement of Science

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 11: Emotions, Aggression, and Stress
Link ID: 27156 - Posted: 04.01.2020

By Matt McGrath Environment correspondent A new study that looks at lifespan in wild mammals shows that females live substantially longer than males. The research finds that, on average, females live 18.6% longer than males from the same species. This is much larger than the well-studied difference between men and women, which is around 8%. The scientists say the differences in these other mammals are due to a combination of sex-specific traits and local environmental factors. In every human population, women live longer than men, so much so that nine out of 10 people who live to be 110 years old are female. This pattern, researchers say, has been consistent since the first accurate birth records became available in the 18th Century. While the same assumption has been held about animal species, large-scale data on mammals in the wild has been lacking, Now, an international team of researchers has examined age-specific mortality estimates for a widely diverse group of 101 species. In 60% of the analysed populations, the scientists found that females outlived the males - on average, they had a lifespan that's 18.6% longer than males. "The magnitude of lifespan and ageing across species is probably an interaction between environmental conditions and sex-specific genetic variations," said lead author Dr Jean-Francois Lemaître, from the University of Lyon, France. He gives the example of bighorn sheep for which the researchers had access to good data on different populations. Where natural resources were consistently available there was little difference in lifespan. However, in one location where winters were particularly severe, the males lived much shorter lives. © 2020 BBC.

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 27137 - Posted: 03.24.2020

By Inés Gutiérrez, Rodrigo Pérez Ortega Earlier this month, Mexico’s leading university, the National Autonomous University of Mexico (UNAM), announced that renowned neuroscientist Ranulfo Romo Trujillo would leave his position after being disciplined for an unspecified offense. According to a 4 March press release from UNAM, Romo Trujillo voluntarily asked to be separated from his job at UNAM’s University City campus in Mexico City. Sources close to the case say he had been temporarily suspended because a female worker made a formal complaint of sexual harassment against him following an incident in January. But current and former UNAM students and staff say that reports of inappropriate behavior by Romo Trujillo had circulated for years before his departure. Romo Trujillo, who works at UNAM’s Institute of Cellular Physiology (IFC), did not respond to repeated requests for comment. He is arguably the most famous neuroscientist in Mexico, studying perception, working memory, and decision-making. He has more than 150 publications, including in top journals such as Science and Nature; is on the editorial board of Neuron and other journals; and is one of 11 Mexican members of the U.S. National Academy of Sciences. IFC physiologist Marcia Hiriart Urdanivia acknowledged in an email to Science that, while director of IFC from 2009 to 2017, she received multiple accounts of sexual harassment or inappropriate conduct by Romo Trujillo. Hiriart Urdanivia says she warned Romo Trujillo that “his career was endangered by such actions.” But the women involved did not choose to file official complaints, she says. As a result, “I had no authority to do anything else.” © 2020 American Association for the Advancement of Science.

Related chapters from BN: Chapter 1: Introduction: Scope and Outlook; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 20: ; Chapter 8: Hormones and Sex
Link ID: 27129 - Posted: 03.21.2020

Nicola Davis From humans to black-tailed prairie dogs, female mammals often outlive males – but for birds, the reverse is true. Now researchers say they have cracked the mystery, revealing that having two copies of the same sex chromosome is associated with having a longer lifespan, suggesting the second copy offers a protective effect. “These findings are a crucial step in uncovering the underlying mechanisms affecting longevity, which could point to pathways for extending life,” the authors write. “We can only hope that more answers are found in our lifetime.” The idea that a second copy of the same sex chromosome is protective has been around for a while, supported by the observation that in mammals – where females have two of the same sex chromosomes – males tend to have shorter lifespans. In birds, males live longer on average and have two Z chromosomes, while females have one Z and one W chromosome. Scientists say they have found the trend is widespread. Writing in the journal Biology Letters, the team report that they gathered data on sex chromosomes and lifespan across 229 animal species, from insects to fish and mammals. Hermaphroditic species and those whose sex is influenced by environmental conditions – such as green turtles – were not included. The results reveal that individuals with two of the same sex chromosomes live 17.6% longer, on average, than those with either two different sex chromosomes or just one sex chromosome. The team say the findings back a theory known as the “unguarded X hypothesis”. In human cells, sex chromosome combinations are generally either XY (male) or XX (female). In females only one X chromosome is activated at random in each cell. © 2020 Guardian News & Media Limited

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 27090 - Posted: 03.04.2020