By JULIET MACUR WILLOW PARK, Tex. — The Hall of Famer Rayfield Wright’s increasingly imperfect memory retains an indelible image of his first N.F.L. start. It was November 1969. The Dallas Cowboys against the Los Angeles Rams. Wright, a Cowboys offensive tackle, lined up opposite Deacon Jones, the Rams’ feared defensive end. “Hey, boy,” Jones growled. “Do your mama know you’re out here?” “What does my mama have anything to do with this?” Wright recalled thinking, losing his concentration just long enough for the ball to be snapped and for Jones to slap his dinner-plate-size right hand violently against Wright’s helmet. He hit him so hard that it sent Wright tumbling backward. Wright remembers being knocked out, then waking to see a galaxy of stars as he lay on the turf, unable to move. “It was as if I’d just been hit in the head by a baseball bat,” he said. He turned toward his sideline, looking to Coach Tom Landry for help. Landry just glanced at him, and then turned away. “Lord,” Wright thought. “I’m in this by myself.” For the longest time, he was sure that was true. It took Wright nearly 40 years to recognize that he probably sustained a concussion in his first N.F.L. start, one of many head injuries he says he had in 13 seasons with the Cowboys. Only recently — albeit through the fog of his worsening dementia, which he acknowledged publicly for the first time last week in an interview at his Texas home — has he realized that he is not in this by himself after all. © 2014 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 19171 - Posted: 01.27.2014

By JANE E. BRODY “Even 50 years after the first surgeon general’s report on smoking and health, we’re still finding out new ways that tobacco kills and maims people,” Dr. Thomas Frieden, director of the Centers for Disease Control and Prevention, recently told me. “It’s astonishing how bad it is.” Dr. Frieden and public health specialists everywhere are seeking better ways to help the 44 million Americans who still smoke to quit and to keep young people from getting hooked on cigarettes. “Fewer than 2 percent of doctors smoke. Why can’t we get to that rate in society as a whole?” he wondered. One reason: Smoking rates are highest among the poor, poorly educated and people with mental illness, populations hard to reach with educational messages and quit-smoking aids. But when I mentioned to Dr. Frieden, a former New York City health commissioner, that the city’s streets are filled with young adult smokers who appear to be well educated and well dressed, he said television seems to have had an outsize influence. Focus groups of white girls in New York private schools have suggested a “Sex in the City” effect, he said: Girls think smoking makes them look sexy. In the last two years, middle-aged men, too, have begun smoking in increasing numbers after a half-century decline. Dr. Frieden cited “Mad Men,” the popular TV series featuring admen in the early 1960s, when well over half of American men smoked. Dr. Frieden said that an antismoking effort begun in 2008 by the World Health Organization “can make a huge difference in curbing smoking, and we should fully implement what we know works.” The program is called Mpower: © 2014 The New York Times Company

Keyword: Drug Abuse
Link ID: 19170 - Posted: 01.27.2014

Mantis shrimp's super colour vision debunked Jessica Morrison Mantis shrimp don’t see colour like we do. Although the crustaceans have many more types of light-detecting cell than humans, their ability to discriminate between colours is limited, says a report published today in Science1. Researchers found that the mantis shrimp’s colour vision relies on a simple, efficient and previously unknown mechanism that operates at the level of individual photoreceptors. The results upend scientists' suspicions that the shrimp, with 12 different types of colour photoreceptors, could see hues that humans, with just 3, could not, says study co-author Justin Marshall, a marine neuroscientist at the University of Queensland in Brisbane, Australia. When the human eye sees a yellow leaf, photoreceptors send signals to the brain announcing relative levels of stimuli: receptors sensitive to red and green light report a lot of activity, whereas receptors sensitive to blue light report little. The brain compares the information from each type of receptor to come up with yellow. Using this system, the human eye can distinguish between millions of different colours. To test whether the mantis shrimp, with its 12 receptors, can distinguish many more, Marshall's team trained shrimp of the species Haptosquilla trispinosa to recognize one of ten specific colour wavelengths, ranging from 400 to 650 nanometres, by showing them two colours and giving them a frozen prawn or mussel when they picked the right one. In subsequent testing, the shrimp could discriminate between their trained wavelengths and another colour 50–100 nanometres up or down the spectrum. But when the difference between the trained and test wavelengths was reduced to 12–25 nanometres, the shrimp could no longer tell them apart. © 2014 Nature Publishing Group

Keyword: Vision; Evolution
Link ID: 19169 - Posted: 01.25.2014

By SINDYA N. BHANOO In pursuit of a mate, male fruit flies often engage in combat, battling one another with their front legs. But when the flies are brothers, they are more likely to cooperate, researchers are reporting. In a new study in the journal Nature, Tommaso Pizzari, a zoologist at the University of Oxford, and colleagues write that brother flies live longer as a result. And there are clear benefits for females who live among brothers: They have a longer reproductive life span, a faster rate of egg production and a greater chance of laying eggs that mature to adulthood. The researchers exposed female flies in a laboratory to several different sets of males — three brothers; two brothers and an unrelated male; and three unrelated males. The most peaceful groups were the ones with three brothers, perhaps because supporting one’s kin is an alternative way to pass on common genes. “You can improve your reproductive success yourself or help individuals who also share your genes,” Dr. Pizzari said. Although fruit flies have been extensively studied in labs, the structure of their natural societies remain a bit of a mystery. © 2014 The New York Times Compan

Keyword: Sexual Behavior; Aggression
Link ID: 19168 - Posted: 01.25.2014

by Erika Engelhaupt Twerking is so 50 million years ago. In fact, it’s probably much older than that. Today, the provocative, butt-shaking dance move is enough of a social phenomenon to merit a word in the dictionary (with twerking defined about as tastefully as possible here by actor Morgan Freeman), but animals have been shaking their hindquarters for ages, for a variety of purposes (more on that below). Black widow spiders are the latest documented twerkers. In their case, it’s the males that shake their rears. Black widow females are aggressive predators and will immediately kill any prey detected in their webs. This presents a problem for males approaching a female to mate; in this case a literal misstep means becoming the female’s dinner. To figure out how the males avoid being eaten (at least before mating), researchers at Simon Fraser University in Canada measured vibrations created by males and by prey in webs of western black widows (Latrodectus hesperus). They compared the vibrations, and the females’ responses, to those of the hobo spider (Tegenaria agrestis), a species in which females rarely attack courting males. To capture the details of small vibrations, they used a fun tool called a laser Doppler vibrometer, which measures small changes in a laser beam aimed at a surface. Sure enough, black widow males appeared to have a death-avoidance strategy. They produced vibrations different from thrashing prey by means of “lengthy andrepeated bouts of abdominal tremulations” averaging 43 wiggles per second, the researchers report January 17 in Frontiers in Zoology. You can see a male's moves in this video: © Society for Science & the Public 2000 - 2014

Keyword: Sexual Behavior; Evolution
Link ID: 19167 - Posted: 01.25.2014

Want to read someone’s mind? Look at their pupils. A person about to answer “yes” to a question, especially if they are more used to answering “no,” will have more enlarged pupils than someone about to answer “no,” according to a new study. Normally, pupils dilate when a person is in a darkened environment to let more light into the eye and allow better vision. But pupil size can also be altered by levels of signaling chemicals naturally produced by the brain. In the study, published online this week in the Proceedings of the National Academy of Sciences, scientists observed the pupils of 29 people as they pressed a “yes” or “no” button to indicate whether they’d seen a difficult-to-detect visual cue on a screen in front of them. When a person was deciding how to answer—in the seconds before pressing a button—their pupils grew larger. And if a person was normally biased toward answering “no” when they weren’t sure on the visual cue, then the pupil change was even more profound in the decision-making seconds before a “yes” answer. The finding could lead to new ways to detect people’s intrinsic biases and how confident they are in an answer given, important variables in many sociological and psychological studies. © 2014 American Association for the Advancement of Science.

Keyword: Attention; Vision
Link ID: 19166 - Posted: 01.25.2014

|By Stephanie Pappas The justices of the Supreme Court may be among the best legal minds in the country, but they have no eye for distances — and new research may help explain why. During oral arguments Wednesday (Jan. 15) in a case about the constitutionality of laws prohibiting protestors from gathering close to abortion clinic entrances, the justices were stumped at the size of the 35-foot-long (10.6 meters) buffer zone in question. "It's pretty much this courtroom, kind of," ABC News quoted Associate Justice Elena Kagan as saying. In fact, the courtroom is more than 90 feet (30 m) long. After a back-and-forth discussion, the deputy solicitor arguing the case clarified that the no-go zone is the size of the 3-point zone on an NBA basketball court. But judging distances and depth may be trickier than it seems. A recent study, published Oct. 23 in the Journal of Neuroscience, finds that people's depth perception depends on their perception of their arm's length. Trick someone into thinking their arm is shorter or longer, and you can influence how they perceive distances between two objects. Depth perception, the ability to judge the distances of objects from one another, is an important ability; without it, one would have no way of knowing that a marble in their hand and a basketball 6 feet away were actually two different sizes. © 2014 Scientific American

Keyword: Vision
Link ID: 19165 - Posted: 01.25.2014

"Everybody has won and all must have prizes," declared the dodo in Alice in Wonderland when asked to judge the winner of a race around a lake. As judgements go, it is admirably even-handed and optimistic. But in the world of mental health the dodo's decision has come to symbolise a bitter dispute that strikes at the very heart of psychotherapy. The "Dodo Bird Verdict", first suggested in the 1930s by the American psychologist Saul Rosenzweig, proposes that the many and various forms of psychological therapy are all equally effective. It makes no difference whether, for example, a person is being treated with techniques drawn from psychoanalysis, neurolinguistic programming, or cognitive behaviour therapy (CBT). What really helps a patient to recover are straightforward factors such as the opportunity to discuss their worries with a skilled and sympathetic therapist or the degree to which they are prepared to engage with the treatment. Understandably, the Dodo Bird Verdict has ruffled many feathers within the profession, and provoked a slew of studies aiming to corroborate or disprove the idea. Are some types of psychotherapy really more effective than others for particular conditions? There is plentiful data to suggest that the answer to that question – contrary to Rosenzweig's theory – is "yes". But that data tends to come from research conducted by proponents of the ostensibly superior therapy, leaving sceptics to conclude that their conclusions are not impartial. This makes the results of a study of treatments for the eating disorder bulimia nervosa, published this month in the American Journal of Psychiatry, all the more convincing. Bulimia is characterised by binge eating, followed by attempts to compensate by making oneself vomit, taking laxatives or diuretics (water tablets), fasting, and/or exercising frantically. Underlying this behaviour is an intense concern – an obsession, even – with body shape and weight. © 2014 Guardian News

Keyword: Anorexia & Bulimia
Link ID: 19164 - Posted: 01.25.2014

|By Stephanie Pappas and LiveScience Even water tastes sweeter when you're in love, new research finds. But not every emotion heightens the senses. Jealousy fails to bring out bitter or sour tastes, despite metaphors that suggest it might, researchers report in the December 2013 issue of the journal Emotion. That love alters one's sensory perceptions and jealousy does not is important to psychologists who study what are called "embodied" metaphors, or linguistic flourishes people quite literally feel in their bones. For example, studies have shown that people induced to feel lonely rate the temperature of the room as colder than do their unprimed counterparts. And the idea that important things have heft plays out physically, too: When someone believes a book is important, it feels heavier. But "just because there is a metaphor does not necessarily imply that we will get these kind of sensations and perception effects," said study researcher Kai Qin Chan, a doctoral candidate at Radboud University Nijmegen in the Netherlands. After seeing previous research on emotional metaphors, like the studies linking loneliness to coldness and heaviness to importance, Chan and his colleagues wanted to expand the question. "We always say, 'love is sweet,' 'honey baby,' this kind of thing," Chan told LiveScience. "We thought, let's see whether this applies to love." © 2014 Scientific American

Keyword: Sexual Behavior; Chemical Senses (Smell & Taste)
Link ID: 19163 - Posted: 01.25.2014

|By Meredith Knight When most of us imagine someone in pain, we feel uncomfortable and want to help. Psychopaths do not: a callousness toward others' suffering is the central feature of a psychopathic personality. Now an imaging study finds that psychopathic inmates have deficits in a key empathy circuit in the brain, pointing to a potential therapeutic target. Jean Decety, a psychologist at the University of Chicago, and his colleagues used functional MRI to scan the brains of 121 male prison inmates while they looked at photos of a painful moment, such as a foot stepping on a nail or a finger being smashed in a drawer. The inmates were instructed to imagine the scenario happening to themselves or to another person, a perspective-switching technique that easily elicits empathy in most people. Inmates who scored the highest on a standard psychopathy test showed a normal response in pain perception and brain centers for emotion when imagining the pain for themselves. Yet when asked to imagine the scenario happening to others, their brains did not show typical connectivity between the amygdala, an area important for fear and emotional processing, and the ventromedial prefrontal cortex, a region vital for emotion regulation, empathy and morality. Some results even indicated that pleasure regions might have become active instead. The brain areas that are undercommunicating in psychopathy “are key for experiencing empathetic concern and caring for one another, which is what empathy is all about and what individuals who score high on psychopathy do not have,” Decety says. © 2014 Scientific American

Keyword: Aggression; Emotions
Link ID: 19162 - Posted: 01.25.2014

|By Ajai Raj As the climate heats up, tempers may follow suit, according to a study published in August 2013 in Nature. Analyzing 60 quantitative studies across fields as disparate as archaeology, criminology, economics, geography, history, political science and psychology, University of California researchers found that throughout history and across the world, higher temperatures, less rainfall and more drought were consistently linked to increased violence. The correlation held true for aggression between individuals, such as domestic abuse and assault, but was even more pronounced for conflict between groups [see timeline]. “We didn't expect for there to be nearly so many convergent findings among so many different researchers,” says economist Solomon Hsiang, now at U.C. Berkeley, who led the study. “We were actually really stunned by the level of consistency in the findings that were out there and by the size of the effects we were observing.” The researchers used statistical modeling to show that aggression scales with a combination of temperature, place and time—for example, if one U.S. county is three degrees Celsius warmer for three months or one African country is 0.6 degree C warmer for a year, statistics reveal an uptick in crime, violence and revolutionary fervor. The reasons behind the climate-violence link are complex and not fully understood, although anyone who has lived through a heat wave can attest to one simple fact: “When people are hot, it makes them cranky,” says Brian Lickel, a social psychologist who is on the faculty of the Psychology of Peace and Violence program at the University of Massachusetts Amherst and who was not involved in the study. “It makes people more prone to anger, it makes people more frustrated, and it makes decision making more impulsive. And that can lead to altercations that escalate to more extreme levels of aggression.” © 2014 Scientific American,

Keyword: Emotions; Aggression
Link ID: 19161 - Posted: 01.25.2014

By Eric Niiler, It may come as a surprise that Finland — one of the least polluted, wealthiest countries, where average life expectancy is among the world’s highest — has the highest rate of Type 1 diabetes. Each year, there are about 58 cases diagnosed per 100,000 children; in the United States there are 24 cases per 100,000, according to the International Diabetes Federation. Some researchers suspect there may be a connection between Finland’s cleanliness and the incidence of the disease there. They are investigating whether the lack of exposure to a specific group of bacteria found in the intestine may be causing weaker immune systems in Finnish children, making them more susceptible to Type 1 diabetes. This so-called hygiene hypothesis — that cleaner living can result in a weaker immune system — has also been linked to ailments such as asthma, allergies and other autoimmune diseases. “We are working along the idea that we have a trigger which most likely is an infectious agent,” said Mikael Knip, a professor of pediatrics at the University of Helsinki who has been studying diabetes for 30 years. “There is an association between such infections and appearance of antibodies.” Just as there are microbes that trigger the disease, Knip says there are also some bacterial or viral infections that, if they occur at an early age, can protect a young child from developing Type 1 diabetes. Type 1 diabetes, which affects approximately 37 million people worldwide, is an autoimmune disease in which the body does not produce sufficient insulin, a hormone needed to break down sugars. Typically diagnosed in children, teens and young adults, the disease can eventually damage the eyes and organs such as the kidneys, and it increases the likelihood of stroke and heart failure. © 1996-2014 The Washington Post

Keyword: Obesity; Neuroimmunology
Link ID: 19160 - Posted: 01.22.2014

By Roni Jacobson Over the past 10 years the number of overdose deaths from prescription painkillers—also known as opioid analgesics—has tripled, from 4,000 people in 1999 to more than 15,000 people every year in the U.S. today. Prescription pain medication now causes more overdose deaths than heroin and cocaine combined. In 2010 one in 20 Americans older than age 12 reported taking painkillers recreationally; some steal from pharmacies or buy them from a dealer, but most have a doctor's prescription or gain access to pills through friends and relatives. Yet millions of people legitimately rely on these medications to cope with the crippling pain they face every day. How do we make sure prescription opioids are readily available to those who depend on them for medical relief but not so available that they become easily abused? Here we break down the steps taken at various levels—and the experts' recommendations for future interventions—to curb prescription opioid addiction and overdose in the U.S. © 2014 Scientific American

Keyword: Drug Abuse; Pain & Touch
Link ID: 19159 - Posted: 01.22.2014

By Michelle Roberts Health editor, BBC News online A magnet device can be used to treat some types of migraine, new UK guidance advises. The watchdog NICE says although there is limited evidence, transcranial magnetic stimulation (TMS) may help ease symptoms in some patients. It says that the procedure is still relatively new and that more data is needed about its long-term safety and efficacy. But it may be useful for patients for whom other treatments have failed. Migraine is common - it affects about one in four women and one in 12 men in the UK. There are several types - with and without aura and with or without headache - and several treatment options, including common painkillers, such as paracetamol. Although there is no cure for migraine, it is often possible to prevent or lessen the severity of attacks. NICE recommends various medications, as well as acupuncture, and now also TMS, under the supervision of a specialist doctor - although it has not assessed whether it would be a cost effective therapy for the NHS. TMS involves using a portable device that is placed on the scalp to deliver a brief magnetic pulse. NICE says doctors and patients might wish to try TMS, but they should be aware about the treatment's uncertainties. Reduction in migraine symptoms may be moderate, it says. Prof Peter Goadsby, chairman of the British Association for the Study of Headache, said many migraine patients stood to benefit from trying TMS. BBC © 2014

Keyword: Pain & Touch
Link ID: 19158 - Posted: 01.22.2014

By CARL ZIMMER The term “X chromosome” has an air of mystery to it, and rightly so. It got its name in 1891 from a baffled biologist named Hermann Henking. To investigate the nature of chromosomes, Henking examined cells under a simple microscope. All the chromosomes in the cells came in pairs. All except one. Henking labeled this outlier chromosome the “X element.” No one knows for sure what he meant by the letter. Maybe he saw it as an extra chromosome. Or perhaps he thought it was an ex-chromosome. Maybe he used X the way mathematicians do, to refer to something unknown. Today, scientists know the X chromosome much better. It’s part of the system that determines whether we become male or female. If an egg inherits an X chromosome from both parents, it becomes female. If it gets an X from its mother and a Y from its father, it becomes male. But the X chromosome remains mysterious. For one thing, females shut down an X chromosome in every cell, leaving only one active. That’s a drastic step to take, given that the X chromosome has more than 1,000 genes. In some cells, the father’s goes dormant, and in others, the mother’s does. While scientists have known about this so-called X-chromosome inactivation for more than five decades, they still know little about the rules it follows, or even how it evolved. In the journal Neuron, a team of scientists has unveiled an unprecedented view of X-chromosome inactivation in the body. They found a remarkable complexity to the pattern in which the chromosomes were switched on and off. © 2014 The New York Times Company

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 19157 - Posted: 01.21.2014

By James Gallagher Health and science reporter, BBC News Doing the night shift throws the body "into chaos" and could cause long-term damage, warn researchers. Shift work has been linked to higher rates of type 2 diabetes, heart attacks and cancer. Now scientists at the Sleep Research Centre in Surrey have uncovered the disruption shift work causes at the deepest molecular level. Experts said the scale, speed and severity of damage caused by being awake at night was a surprise. The human body has its own natural rhythm or body clock tuned to sleep at night and be active during the day. It has profound effects on the body, altering everything from hormones and body temperature to athletic ability, mood and brain function. The study, published in Proceedings of the National Academy of Sciences, followed 22 people as their body was shifted from a normal pattern to that of a night-shift worker. Blood tests showed that normally 6% of genes - the instructions contained in DNA - were precisely timed to be more or less active at specific times of the day. Once the volunteers were working through the night, that genetic fine-tuning was lost. "Over 97% of rhythmic genes become out of sync with mistimed sleep and this really explains why we feel so bad during jet lag, or if we have to work irregular shifts," said Dr Simon Archer, one of the researchers at the University of Surrey. BBC © 2014

Keyword: Biological Rhythms; Genes & Behavior
Link ID: 19156 - Posted: 01.21.2014

by Laura Sanders Growing up, I loved it when my parents read aloud the stories of the Berenstain Bears living in their treehouse. So while I was pregnant with my daughter, I imagined lots of cuddly quiet time with her in a comfy chair, reading about the latest adventures of Brother and Sister. Of course, reality soon let me know just how ridiculous that idea was. My newborn couldn’t see more than a foot away, cried robustly and frequently for mysterious reasons, and didn’t really understand words yet. Baby V was simply not interested in the latest dispatch from Bear County. When I started reading child development expert Elaine Reese’s new book Tell Me a Story, I realized that I was not the only one with idyllic story time dreams. Babies and toddlers are squirmy, active people with short attention spans. “Why, then, do we cling to this soft-focus view of storytelling when we know it is unrealistic?” she writes. These days, as Baby V closes in on the 1-year mark, she has turned into a most definite book lover. But it’s not the stories that enchant her. It’s holding the book, turning its pages back to front to back again, flipping it over and generally showing it who’s in charge. Every so often I can entice Baby V to sit on my lap with a book, but we never read through a full story. Instead, we linger on the page with all the junk food that the Hungry Caterpillar chomps through, sticking our fingers in the little holes in the pages. And we make Froggy pop in and out of the bucket. And we study the little goats as they climb up and up and up on the hay bales. © Society for Science & the Public 2000 - 2014

Keyword: Language; Development of the Brain
Link ID: 19155 - Posted: 01.21.2014

by Bethany Brookshire There are some scientific topics that are bound to generate excitement. A launch to the moon, a potential cure for cancer or any study involving chocolate will always make the news. And then of course there’s caffeine. More than half of Americans have a daily coffee habit, not to mention the boost offered by tea, soda, chocolate and energy drinks. We’d all love to believe that it has more benefit than just papering over a poor night’s sleep. This week, scientists reported that caffeine could give a jolt to memory consolidation, the step right after your brain acquires a memory. During memory consolidation, activity patterns laid down in your brain become more permanent. The study suggested that caffeine might perk up this stage of memory formation. But while it’s an interesting finding, the scientific brew may not be strong enough to justify your coffee habit. Caffeine is a great way to wake you up. It blocks the action of adenosine, a chemical messenger that promotes sleep. Caffeine also has indirect effects on other chemical messengers such as norepinephrine, the neurotransmitter that gives us our famous “fight or flight” response. The net result is increased attention, wakefulness and faster responses. But attention, focus and response time are not memory. And previous studies of memory, says neuroscientist Michael Yassa, the lead author on the new study, were “all over the place.” So Yassa, then at Johns Hopkins University (he’s now at the University of California, Irvine), and undergraduate student Daniel Borota decided to study the effects of caffeine on memory “in a rigorous way.” © Society for Science & the Public 2000 - 2014

Keyword: Learning & Memory; Drug Abuse
Link ID: 19154 - Posted: 01.20.2014

US President Barack Obama has said smoking marijuana is no more dangerous than alcohol, but still called it a "bad idea". Speaking to The New Yorker magazine, he said it was wrong to think legalising the drug would be "a panacea" that could solve many social problems. Mr Obama was referring to recent legalisation of marijuana in the states of Colorado and Washington. He has previously admitted using the drug when he was young. "As has been well documented, I smoked pot as a kid, and I view it as a bad habit and a vice, not very different from the cigarettes that I smoked as a young person up through a big chunk of my adult life," Mr Obama said. But he added that in terms of its impact on the individual consumer "I don't think it is more dangerous than alcohol". He also said that poor people - many of them African Americans and Latinos - were disproportionately punished for marijuana use, whereas middle-class users mostly escaped harsh penalties. "It's important for society not to have a situation in which a large portion of people have at one time or another broken the law and only a select few get punished." Mr Obama described the legalisation of marijuana in Colorado and Washington as a challenging "experiment". BBC © 2014

Keyword: Drug Abuse
Link ID: 19153 - Posted: 01.20.2014

by Susan Milius For springtails, sex can be an Easter egg hunt. Many males of the tiny soil organisms sustain their species by leaving drops of sperm glistening here and there in the landscape in case a female chooses to pick one up. “The male never meets the female,” says Zaira Valentina Zizzari of VU University Amsterdam, who studies a species of these extreme loners called Orchesella cincta. Just about every degree of mating intimacy, from unseen sperm donors to elaborate courtship and internal insemination, shows up in springtails. That makes the ancient group — which may not belong to the insects but to another set of six-legged arthropods on its own evolutionary trajectory — a treasure trove for biologists studying sex. In O. cincta, little brown-and-white males roam the leaf litter making no apparent effort to find a female. Instead, males pause here and there for a few seconds to leave behind white stalks topped by a shiny-coated globes, each holding more than 1,000 sperm. Sperm on a stalk is still viable after sitting two days in the lab. Outdoors it may not last so long. “You have a lot of rivals searching for sperm just to destroy it,” Zizzari says. Males eat rivals’ sperm. Given the rivalry, it wouldn’t be surprising if males engaged in an arms race to produce more sperm stalks than their competitors. But Zizzari was surprised to discover that male O. cincta make fewer sperm packages when a competitor is sperm-dotting the neighborhood. Maybe he’s enhancing the few he makes with extra sex appeal, Zizzari mused. To test the idea, she offered lab females a choice of globes from males with rivals or those made by an uncrowded guy. © Society for Science & the Public 2000 - 2014

Keyword: Sexual Behavior
Link ID: 19152 - Posted: 01.20.2014