Chapter 16. None
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By Catherine Matacic Simi Etedgi leans forward as she tells her story for the camera: The year was 1963, and she was just 15 as she left Morocco for Israel, one person among hundreds of thousands leaving for the new state. But her forward lean isn’t a casual gesture. Etedgi, now 68, is one of about 10,000 signers of Israeli Sign Language (ISL), a language that emerged only 80 years ago. Her lean has a precise meaning, signaling that she wants to get in an aside before finishing her tale. Her eyes sparkle as she explains that the signs used in the Morocco of her childhood are very different from those she uses now in Israel. In fact, younger signers of ISL use a different gesture to signal an aside—and they have different ways to express many other meanings as well. A new study presented at the Evolution of Language meeting here last month shows that the new generation has come up with richer, more grammatically complex utterances that use ever more parts of the body for different purposes. Most intriguing for linguists: These changes seem to happen in a predictable order from one generation to the next. That same order has been seen in young sign languages around the world, showing in visible fashion how linguistic complexity unfolds. This leads some linguists to think that they may have found a new model for the evolution of language. “This is a big hypothesis,” says cognitive scientist Ann Senghas of Barnard College in New York City, who has spent her life studying Nicaraguan Sign Language (NSL). “It makes a lot of predictions and tries to pull a lot of facts together into a single framework.” Although it’s too early to know what the model will reveal, linguists say it already may have implications for understanding how quickly key elements of language, from complex words to grammar, have evolved. © 2016 American Association for the Advancement of Science.
Link ID: 22130 - Posted: 04.23.2016
Anna Nowogrodzki There’s a little too much wishful thinking about mindfulness, and it is skewing how researchers report their studies of the technique. Researchers at McGill University in Montreal, Canada, analysed 124 published trials of mindfulness as a mental-health treatment, and found that scientists reported positive findings 60% more often than is statistically likely. The team also examined another 21 trials that were registered with databases such as ClinicalTrials.gov; of these, 62% were unpublished 30 months after they finished. The findings — reported in PLoS ONE on 8 April1 — hint that negative results are going unpublished. Mindfulness is the practice of being aware of thoughts and feelings without judging them good or bad. Mental-health treatments that focus on this method include mindfulness-based stress reduction — an 8-week group-based programme that includes yoga and daily meditation — and mindfulness-based cognitive therapy. A bias toward publishing studies that find the technique to be effective withholds important information from mental-health clinicians and patients, says Christopher Ferguson, a psychologist at Stetson University in Florida, who was not involved in the study. “I think this is a very important finding,” he adds. “We’ll invest a lot of social and financial capital in these issues, and a lot of that can be misplaced unless we have good data.” © 2016 Nature Publishing Group
Link ID: 22129 - Posted: 04.23.2016
By Patrick Monahan You might have seen a video from David Attenborough’s The Life of Birds series where a male superb lyrebird (Menura novaehollandiae) attempts to lure a mate by imitating a smorgasbord of bird calls and even chainsaws. As nature’s show-offs, male animals tend to have more elaborate colors and courtship behaviors than their female counterparts, so it’s typical that the male would get the public’s attention. The same is true in science: Plenty of female birds sing songs, but researchers have in the past often dismissed them as simply being evolutionary tag-alongs of the males’ “come hither” calls. Now, by recording the calls of female superb lyrebirds, researchers have found that they can keep up with the boys just fine. According to a study published this week in Frontiers in Ecology and Evolution, the females collectively imitated 19 other species of birds, and also sang lyrebird-specific songs. And they changed their songs depending on context, using more lyrebird-specific “whistle” calls when out foraging and vying for territory, but more mimicking calls when defending their nests (as in the audio file below). The fact that the females change their type of call depending on the context makes it likely that these songs evolved in their own right—and the males’ calls aren’t so special after all. Plus, that part about the chainsaw? It probably doesn’t even happen in the wild. © 2016 American Association for the Advancement of Science
By DAN LEVIN VANCOUVER, British Columbia — Dave Napio started doing heroin over four decades ago, at 11 years old. Like many addicts these days, he heads to Vancouver’s gritty Downtown Eastside neighborhood when he needs a fix. But instead of seeking out a dealer in a dark alley, Mr. Napio, 55, gets his three daily doses from a nurse at the Crosstown Clinic, the only medical facility in North America permitted to prescribe the narcotic at the center of an epidemic raging across the continent. And instead of robbing banks and jewelry stores to support his habit, Mr. Napio is spending time making gold and silver jewelry, hoping to soon turn his hobby into a profession. “My whole life is straightening out,” Mr. Napio, who spent 22 of his 55 years in prison, said during a recent interview in the clinic’s mirror-lined injection room. “I’m becoming the guy next door.” Mr. Napio is one of 110 chronic addicts with prescriptions for diacetylmorphine hydrochloride, the active ingredient in heroin, which he injects three times a day at Crosstown as part of a treatment known as heroin maintenance. The program has been so successful at keeping addicts out of jail and away from emergency rooms that its supporters are seeking to expand it across Canada. But they have been hindered by a tangle of red tape and a yearslong court battle reflecting a conflict between medicine and politics on how to address drug addiction. The clinic’s prescription program began as a clinical trial more than a decade ago. But it has garnered more interest recently as a plague of illicit heroin use and fatal overdoses of legal painkillers has swept across the United States, fueling frustration over ideological and legal obstacles to forms of treatment that studies show halt the spread of disease through needles and prevent deaths. © 2016 The New York Times Company
Keyword: Drug Abuse
Link ID: 22123 - Posted: 04.21.2016
Nicola Davis The proportion of older people suffering from dementia has fallen by a fifth over the past two decades with the most likely explanation being because men are smoking less and living healthier lives, according to new scientific research. A team from three British universities concluded that as a result the number of new cases of dementia is lower than had been predicted in the 1990s, estimated at around 210,000 a year in the UK as opposed to 250,000. The findings are potentially significant because they suggest that it is possible to take preventative action, such as stopping smoking and reducing cholesterol, that could help avoid the condition. “Physical health and brain health are clearly highly linked,” said Carol Brayne of Cambridge University, who co-authored the study. Nick Fox, professor of neurology at University College, London, who was not involved in the study, agrees: “This does suggest that our risk, in any particular age in later life, can be reduced probably by what we do 10, 20 or 30 years before.” The scientists found that new cases of dementia had dropped from 20.1 in every 1,000 people per year in the first study conducted in the early 1990s to 17.7 in the second, which looked at new cases between 2008 and 2013. When sex and age differences were taken into account, the dementia rates were found to have dropped by 20%. The trend emerges from a dramatic drop in new cases for men across all age groups. In the 1990s study, for every 1,000 men aged 70-74, 12.9 went on to develop dementia within a year. In the second study, 20 years later, that figure had dropped to only 8.7 men. For men aged 65-69 the rate of new cases had more than halved between the two studies. © 2016 Guardian News and Media Limited
Link ID: 22122 - Posted: 04.20.2016
By Mitch Leslie The worst part of being sick isn’t always the muscle aches and coughing. It’s the foggy head, the crankiness, the apathy, and the fatigue—in short, what researchers call sickness behavior. A new study uncovers a molecular mechanism that explains why we feel so crummy when we’re under the weather. “It’s a nice study that’s covered a lot of ground,” says neuroimmunologist Colm Cunningham of Trinity College in Dublin who wasn’t connected to the research. “What they’ve found is very plausible.” Although sickness behavior is unpleasant, researchers think the symptoms we suffer during a viral or bacterial infection are beneficial, enabling us to divert our energy to fighting the pathogens that have invaded our bodies. For cancer patients and people with autoimmune diseases, however, sickness behavior can be an unwanted side effect of treatment with immune molecules known as interferons, which our cells naturally release when we have an infection. The condition has posed a puzzle for researchers because they assumed the blood-brain barrier, a protective system that excludes most pathogens and immune molecules from the brain, would block signals from the immune system. Although scientists have identified several mechanisms that allow such messages to cross the barrier and influence behavior, the question of how the immune system and brain communicate “has been only partially answered,” says immunophysiologist Keith Kelley of the University of Illinois, Urbana-Champaign, who wasn’t connected to the new study. © 2016 American Association for the Advancement of Science.
Link ID: 22121 - Posted: 04.20.2016
Melissa Davey Researchers have developed the world’s first blood test that can detect the abnormal metabolism of blood cells in people with Parkinson’s disease, which means the blood test could be used to diagnose the disorder. At present the only way to diagnose Parkinson’s disease, a degenerative neurological condition, is through ordering a range of tests and scans to rule out other disorders, combined with examining symptoms. Patients are often diagnosed only after they have developed symptoms and brain cells have already been destroyed. While there is no cure for Parkinson’s, early detection allows treatment with medication and physiotherapy to begin, which may slow the deterioration of motor functions in patients. Because diagnosing the disease is a process of elimination, and the symptoms mimic those of other neurological disorders, patients are also at risk being diagnosed and treated for the wrong disease. The group of Australian researchers from La Trobe University believe their blood test will enable doctors to detect Parkinson’s disease with unprecedented reliability and lead to earlier treatment. Their findings are under review by an international medical journal. © 2016 Guardian News and Media Limited
Link ID: 22120 - Posted: 04.20.2016
By Sarah Kaplan We know where the human story started: In Africa, millions of years ago, with diminutive people whose brains were just a third of the size of ours. And we know where it ended: with us. Yet a lot of what happened in between is still debated, including the question of how humans' bodies and noggins got so much bigger than our ancestors'. The traditional thinking is that the growth of both was spurred by the process of natural selection. The evolutionary advantages of a big body and a big brain are plentiful, so it seems reasonable to think that each developed independent of the other in response to the demands of survival in a hostile world. But a new study in the journal Current Anthropology suggests that, while our brains are certainly an advantageous adaptation, our imposing physiques (such as they are) are more of an evolutionary fluke. That's because the genes that determine brain and body size are the same, argues Mark Grabowski, a fellow at the American Museum of Natural History. So as humans evolved bigger and bigger brains, our bodies "just got pulled along." Grabowski acknowledges that it may seem like a counterintuitive conclusion — most of us learned in high school biology that evolution is about adapting to circumstances and that only the fittest survive. We're not used to thinking of traits as a product of happenstance. But evolutionary scientists know that lots of traits — even ultimately beneficial ones — are just the luck of the draw.
Link ID: 22119 - Posted: 04.20.2016
By JAMES GORMAN Bees find nectar and tell their hive-mates; flies evade the swatter; and cockroaches seem to do whatever they like wherever they like. But who would believe that insects are conscious, that they are aware of what’s going on, not just little biobots? Neuroscientists and philosophers apparently. As scientists lean increasingly toward recognizing that nonhuman animals are conscious in one way or another, the question becomes: Where does consciousness end? Andrew B. Barron, a cognitive scientist, and Colin Klein, a philosopher, at Macquarie University in Sydney, Australia, propose in Proceedings of the National Academy of Sciences that insects have the capacity for consciousness. This does not mean that a honeybee thinks, “Why am I not the queen?” or even, “Oh, I like that nectar.” But, Dr. Barron and Dr. Klein wrote in a scientific essay, the honeybee has the capacity to feel something. Their claim stops short of some others. Christof Koch, the president and chief scientific officer of the Allen Institute for Brain Science in Seattle, and Giulio Tononi, a neuroscientist and psychiatrist at the University of Wisconsin, have proposed that consciousness is nearly ubiquitous in different degrees, and can be present even in nonliving arrangements of matter, to varying degrees. They say that rather than wonder how consciousness arises, one should look at where we know it exists and go from there to where else it might exist. They conclude that it is an inherent property of physical systems in which information moves around in a certain way — and that could include some kinds of artificial intelligence and even naturally occurring nonliving matter. © 2016 The New York Times Company
Link ID: 22118 - Posted: 04.19.2016
Rachel Becker A highly contagious and deadly animal brain disorder has been detected in Europe for the first time. Scientists are now warning that the single case found in a wild reindeer might represent an unrecognized, widespread infection. Chronic wasting disease (CWD) was thought to be restricted to deer, elk (Cervus canadensis) and moose (Alces alces) in North America and South Korea, but on 4 April researchers announced that the disease had been discovered in a free-ranging reindeer (Rangifer tarandus tarandus) in Norway. This is both the first time that CWD has been found in Europe and the first time that it has been found in this species in the wild anywhere in the world. “It’s worrying — of course, especially for animals. It’s a nasty disease,” says Sylvie Benestad, an animal-disease researcher at the Norwegian Veterinary Institute in Oslo who, along with colleague Turid Vikøren, diagnosed the diseased reindeer. A key question now is whether this is a rare — even unique — case, or if the disease is widespread but so far undetected in Europe. “If it’s similar to our prion disease in the United States and Canada, the disease is subtle and it would be easy to miss,” says Christina Sigurdson, a pathologist at the University of California, San Diego, who has shown that reindeer can contract CWD in a laboratory environment1. © 2016 Nature Publishing Group,
Link ID: 22117 - Posted: 04.19.2016
Scientists believe injections of a natural protein may lessen the symptoms and progress of Alzheimer's dementia after promising early trials in mice. The treatment - IL 33 - appeared to improve memory and help clear and prevent brain deposits similar to those seen in people with Alzheimer's. Tentative human studies of the treatment will soon begin, but experts say it will take many years to know if it could help patients in real life. The work is published in PNAS journal. Interleukin 33, or IL 33 for short, is made by the body as part of its immune defence against infection and disease, particularly within the brain and spinal cord. And patients with Alzheimer's have been found to have lower amounts of IL 33 in their brains than healthy adults. The researchers from the University of Glasgow and the Hong Kong University of Science and Technology tested what effect a boost of IL 33 might have on mice bred to have brain changes akin to Alzheimer's. The rodents rapidly improved their memory and cognitive function to that of the age-matched normal mice within a week of having the injections. Prof Eddy Liew, who led the work at the University of Glasgow, is excited but cautious about his findings. "Exciting as it is, there is some distance between laboratory findings and clinical applications. There have been enough false 'breakthroughs' in the medical field to caution us not to hold our breath until rigorous clinical trials have been done." © 2016 BBC.
Link ID: 22115 - Posted: 04.19.2016
By Jillian Bell, CBC News New medical marijuana products produced by yeast could soon be on the market, the co-founder of a biotech company says. That could potentially lead to a wider range of cannabinoid-based drugs that proponents say could be more effective for treating certain medical conditions than medical marijuana itself. The appropriate use of medical marijuana has been a controversial topic, with many arguing that further research is needed to evaluate its efficacy as a treatment for a variety of ailments. In Canada, where the Liberal government has said it will legalize marijuana, medical marijuana is already used to treat a variety of conditions and symptoms, including lack of appetite in people with HIV/AIDS and nausea in those undergoing cancer treatment. The most well-known cannabinoid is tetrahydrolcannabinol, or THC, which is approved by the U.S. Food and Drug Administration to treat nausea and improve appetite. It's found in large amounts in marijuana plants, which is the reason why medical marijuana is often prescribed to treat nausea and increase appetite. But other cannabinoids, like cannabidiol (CBD) and cannabigerol (CBG) may have the potential to be potent treatments for other conditions as well. CBG also has its own medical properties. But it can also be easily chemically converted into other cannabinoids, including THC. ©2016 CBC/Radio-Canada.
Keyword: Drug Abuse
Link ID: 22111 - Posted: 04.18.2016
By David Shultz Mice supposedly don't speak, so they can't stutter. But by tinkering with a gene that appears to be involved in human speech, researchers have created transgenic mice whose pups produce altered vocalizations in a way that is similar to stuttering in humans. The mice could make a good model for understanding stuttering; they could also shed more light on how mutations in the gene, called Gnptab, cause the speech disorder. Stuttering is one of the most common speech disorders in the world, affecting nearly one out of 100 adults in the United States. But the cause of the stammering, fragmented speech patterns remains unclear. Several years ago, researchers discovered that stutterers often have mutations in a gene called Gnptab. Like a dispatcher directing garbage trucks, Gnptab encodes a protein that helps to direct enzymes into the lysosome—a compartment in animal cells that breaks down waste and recycles old cellular machinery. Mutations to other genes in this system are known to lead to the buildup of cellular waste products and often result in debilitating diseases, such as Tay-Sachs. How mutations in Gnptab causes stuttered speech remains a mystery, however. To get to the bottom of things, neuroscientist Terra Barnes and her team at Washington University in St. Louis in Missouri produced mice with mutation in the Gnptab gene and studied whether it affected the ultrasonic vocalizations that newly born mouse pups emit when separated from their mothers. Determining whether a mouse is stuttering is no easy task; as Barnes points out, it can even be difficult to tell whether people are stuttering if they’re speaking a foreign language. So the team designed a computer program that listens for stuttering vocalization patterns independent of language. © 2016 American Association for the Advancement of Science.
Link ID: 22110 - Posted: 04.16.2016
By Matthew Hutson Bad news for believers in clairvoyance. Our brains appear to rewrite history so that the choices we make after an event seem to precede it. In other words, we add loops to our mental timeline that let us feel we can predict things that in reality have already happened. Adam Bear and Paul Bloom at Yale University conducted some simple tests on volunteers. In one experiment, subjects looked at white circles and silently guessed which one would turn red. Once one circle had changed colour, they reported whether or not they had predicted correctly. Over many trials, their reported accuracy was significantly better than the 20 per cent expected by chance, indicating that the volunteers either had psychic abilities or had unwittingly played a mental trick on themselves. The researchers’ study design helped explain what was really going on. They placed different delays between the white circles’ appearance and one of the circles turning red, ranging from 50 milliseconds to one second. Participants’ reported accuracy was highest – surpassing 30 per cent – when the delays were shortest. That’s what you would expect if the appearance of the red circle was actually influencing decisions still in progress. This suggests it’s unlikely that the subjects were merely lying about their predictive abilities to impress the researchers. The mechanism behind this behaviour is still unclear. It’s possible, the researchers suggest, that we perceive the order of events correctly – one circle changes colour before we have actually made our prediction – but then we subconsciously swap the sequence in our memories so the prediction seems to come first. Such a switcheroo could be motivated by a desire to feel in control of our lives. © Copyright Reed Business Information Ltd.
Link ID: 22109 - Posted: 04.16.2016
By Robin Wylie Bottlenose dolphins have been observed chattering while cooperating to solve a tricky puzzle – a feat that suggests they have a type of vocalisation dedicated to cooperating on problem solving. Holli Eskelinen of Dolphins Plus research institute in Florida and her colleagues at the University of Southern Mississippi presented a group of six captive dolphins with a locked canister filled with food. The canister could only be opened by simultaneously pulling on a rope at either end. The team conducted 24 canister trials, during which all six dolphins were present. Only two of the dolphins ever managed to crack the puzzle and get to the food. The successful pair was prolific, though: in 20 of the trials, the same two adult males worked together to open the food canister in a matter of few minutes. In the other four trials, one of the dolphins managed to solve the problem on its own, but this was much trickier and took longer to execute. But the real surprise came from recordings of the vocalisations the dolphins made during the experiment. The team found that when the dolphins worked together to open the canister, they made around three times more vocalisations than they did while opening the canister on their own or when there was either no canister present or no interaction with the canister in the pool. © Copyright Reed Business Information Ltd.
By BENEDICT CAREY Five years ago, a college freshman named Ian Burkhart dived into a wave at a beach off the Outer Banks in North Carolina and, in a freakish accident, broke his neck on the sandy floor, permanently losing the feeling in his hands and legs. On Wednesday, doctors reported that Mr. Burkhart, 24, had regained control over his right hand and fingers, using technology that transmits his thoughts directly to his hand muscles and bypasses his spinal injury. The doctors’ study, published by the journal Nature, is the first account of limb reanimation, as it is known, in a person with quadriplegia. Doctors implanted a chip in Mr. Burkhart’s brain two years ago. Seated in a lab with the implant connected through a computer to a sleeve on his arm, he was able to learn by repetition and arduous practice to focus his thoughts to make his hand pour from a bottle, and to pick up a straw and stir. He was even able to play a guitar video game. “It’s crazy because I had lost sensation in my hands, and I had to watch my hand to know whether I was squeezing or extending the fingers,” Mr. Burkhart, a business student who lives in Dublin, Ohio, said in an interview. His injury had left him paralyzed from the chest down; he still has some movement in his shoulders and biceps. The new technology is not a cure for paralysis. Mr. Burkhart could use his hand only when connected to computers in the lab, and the researchers said there was much work to do before the system could provide significant mobile independence. But the field of neural engineering is advancing quickly. Using brain implants, scientists can decode brain signals and match them to specific movements. Previously, people have learned to guide a cursor on a screen with their thoughts, monkeys have learned to skillfully use a robotic arm through neural signals and scientists have taught monkeys who were partly paralyzed to use an arm with a bypass system. This new study demonstrates that the bypass approach can restore critical skills to limbs no longer directly connected to the brain. © 2016 The New York Times Company
Link ID: 22106 - Posted: 04.14.2016
By Amy Ellis Nutt I saw it all: The beginning of Time and the end of Time. Creation and annihilation. Somehow I’d slipped through a seam in the space-time continuum, and from my privileged mental perch I'd peered into the center of the universe. I was exhilarated and drew diagrams of my visions, trying to figure out what it all meant. But when I shared those visions with friends, they were confused and concerned. I was manic, they said, and making no sense. We were at an impasse. Was I sick – or simply in search of myself? Those questions from my own past hovered in the background while I watched two very different documentaries recently. Both explore bipolar illness -- a diagnosis I received more than 25 years ago and one that 5.5 million Americans share. But the films come from very different perspectives. The first, "Ride the Tiger: A Guide Through the Bipolar Brain," was produced by Detroit Public TV and airs on PBS Wednesday. It chronicles the latest in cutting-edge research into bipolar disorder and in doing so firmly plants its flag in the biological camp: The disorder is about misfiring brain circuits, genetic mutations, neurochemical disruptions and other neurological processes not yet delineated. The result is dramatic swings in mood and behavior that affect a person's ability to think clearly. "Ride the Tiger" features appearances by former congressman Patrick Kennedy and the late actress Patty Duke, both of whom talk about their own experiences. The second documentary, "Bipolarized: Re-Thinking Mental Illness," questions the very reality of the disorder -- at least for one former psychiatric patient.
Link ID: 22104 - Posted: 04.14.2016
Eleanor Ainge Roy in Dunedin An octopus has made a brazen escape from the national aquarium in New Zealand by breaking out of its tank, slithering down a 50-metre drainpipe and disappearing into the sea. In scenes reminiscent of Finding Nemo, Inky – a common New Zealand octopus – made his dash for freedom after the lid of his tank was accidentally left slightly ajar. Staff believe that in the middle of the night, while the aquarium was deserted, Inky clambered to the top of his cage, down the side of the tank and travelled across the floor of the aquarium. Rob Yarrell, national manager of the National Aquarium of New Zealand in Napier, said: “Octopuses are famous escape artists. “But Inky really tested the waters here. I don’t think he was unhappy with us, or lonely, as octopus are solitary creatures. But he is such a curious boy. He would want to know what’s happening on the outside. That’s just his personality.” One theory is that Inky slid across the aquarium floor – a journey of three or four metres – and then, sensing freedom was at hand, into a drainpipe that lead directly to the sea. The drainpipe was 50 metres long, and opened on to the waters of Hawke’s Bay, on the east coast of New Zealand’s North Island. Another possible escape route could have involved Inky squeezing into an open pipe at the top of his tank, which led under the floor to the drain. © 2016 Guardian News and Media Limited
By Gareth Cook What are the most intelligent creatures on the planet? Humans come first. (Though there are days when we have to wonder.) After Homo sapiens, most people might answer chimpanzees, and then maybe dogs and dolphins. But what of birds? The science writer Jennifer Ackerman offers a lyrical testimony to the wonders of avian intelligence in her new book, “The Genius of Birds.” There have long been hints of bird smarts, but it’s become an active field of scientific inquiry, and Ackerman serves as tour guide. She answered questions from Mind Matters editor Gareth Cook. What drew you to birds? I’ve watched birds for most of my life. I admire all the usual things about them. Their plumage and song. Their intense way of living. Their flight. I also admire their resourcefulness and pluck. I’ve always been intrigued by their apparently smart behavior, whether learned or innate. I grew up in Washington, D.C. — the second youngest in a gaggle of five girls. My parents had precious little time for one-on-one. Especially my dad, who had a demanding government job. So when he asked me if I wanted to go birdwatching with him one spring morning when I was seven or eight, I jumped at the chance. It was magical, going out in the dark woods along the C&O canal and listening for bird song. My father had learned his calls and songs in Boy Scout camp from an expert, an elderly Greek man named Apollo, so he was pretty good at identifying birds, even the shy woodland species. Eventually he gave me my own copy of Peterson’s Field Guide, along with a small pair of binoculars. I’ve loved birds ever since. My first run in with a clever bird was on our dining room table. We had a pet parakeet, a budgerigar named Gre-Gre, who was allowed to fly around the dining room and perch on our head or shoulders. He had a kind of social genius. He made you love him. But at breakfast, it was impossible to eat your cereal without his constant harassment. He liked to perch on the edge of my bowl and peck at the cereal, flapping his wings frantically to keep his balance, splashing my milk. I’d build a barricade of boxes around my place setting, but he always found a way in, moving a box or popping over the top. He was a good problem-solver. © 2016 Scientific American
By Virginia Morell Moths have an almost fatal attraction to lights—so much so that we say people are drawn to bad ends “like moths to a flame.” But in this age of global light pollution, that saying has a new poignancy: Moths, which are typically nocturnal insects, are dying in droves at artificial lights. The high levels of mortality should have evolutionary consequences, leading to moths that avoid lights, biologists say. To find out, two scientists tested the flight-to-light behavior of 1048 adult ermine moths (Yponomeuta cagnagella, shown above) in Europe. The researchers collected the insects in 2007 as larvae that had just completed their first molt. Three hundred and twenty came from populations that lived where the skies were largely dark; 728 were gathered in light polluted areas. They were raised in a lab with 16 hours of daylight and 8 hours of darkness daily while they completed their life stages. Two to 3 days after emerging as moths, they were released in a flight cage with a fluorescent tube at one side. Moths from high light pollution areas were significantly less attracted to the light than those from the darker zones, the scientists report in today’s issue of Biology Letters. Overall, moths from the light-polluted populations had a 30% reduction in the flight-to-light behavior, indicating that this species is evolving, as predicted, to stay away from artificial lights. That change should increase these city moths’ reproductive success. But their success comes at a cost: To avoid the lights, the moths are likely flying less, say the scientists, so they aren’t pollinating as many flowers or feeding as many spiders and bats. © 2016 American Association for the Advancement of Science.
Link ID: 22100 - Posted: 04.13.2016