Movement in our field of vision can drastically affect the way our brain perceives the world around us. To explain these phenomena, visual researchers have come up with some mind-bending new motion perception illusions. Here, New Scientist brings you our pick of the best. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 14587 - Posted: 10.26.2010

By Rachel Ehrenberg Inhaling a blast of bitter fumes sends a breathe-easy message to the lungs, a new study shows. Stimulating bitterness receptors in the lungs relaxes and opens the airways, a counterintuitive finding that could lead to new asthma medications, scientists report online October 24 in Nature Medicine. Bitter-taste receptors just like the ones on the tongue abound on the smooth muscle tissue that wraps around the airway tubes leading to the lungs, reports a team from the University of Maryland and Johns Hopkins in Baltimore. In mice bred to have asthma, inhaled bitter compounds such as quinine did a better job of relaxing airways than did the standard asthma drug albuterol. These bitter-taste receptors in lung muscles should be good targets for new asthma medications that are based on the multitude of molecules known to stimulate bitter receptors, says Mathur Kannan, a pharmacologist in the College of Veterinary Medicine at the University of Minnesota in St. Paul. The relaxation response to bitter-flavored air remains somewhat puzzling. In the mouth, bitter receptors are part of the body’s first line of defense against possibly poisonous compounds. Cells lining the upper part of the respiratory tract also have bitter-taste receptors, scientists reported earlier this year. But there, they can trigger an “out, out” reaction, stimulating the featherlike cilia of the airways to push whatever’s nearby up and away. So it seemed more logical that muscles controlling air flow to lungs would constrict when stimulated by potential toxins, says Stephen Liggett of the University of the Maryland School of Medicine in Baltimore, who led the new work. © Society for Science & the Public 2000 - 2010

Keyword: Chemical Senses (Smell & Taste)
Link ID: 14586 - Posted: 10.26.2010

Roger Dobson At school they are more popular, have more friends and are less likely to be bullied. And as adults, they have more sexual partners, and are more likely to be married, have a good job, and earn a higher salary – around 10 per cent more than plain Joes and Janes. They are also perceived to be healthier, smarter, and more trustworthy, and if they go into politics they are more likely to be elected. But why are some people seen as attractive and others not? And why have we evolved to find some features attractive and others not? According to new research, it may all be down to oxidative stress and antioxidants. Psychologists have discovered that men who were rated as the most physically attractive by women have the lowest levels of markers of oxidative stress. "These findings have several important implications," says psychologist Dr Steven Gangestad who led the study. "They fit in with the idea that women evolved to find particular features attractive because those features are related to low levels of oxidative stress." Attractiveness has long been a source of fascination for psychologists, anthropologists, behavioural scientists – and singletons. Some have investigated the many life advantages that come with attractiveness, while others have looked at whether or not it is a learned criterion. One school of thought has it that attraction to specific features is not learned, but has evolved over time as a way of distinguishing the virile from the weak. This evolutionary theory is backed up by much research, including studies showing that newborn babies have a preference for attractive faces. It's suggested that physical attractiveness may serve as a biological signal of good health. In ancestral time, being able to spot an attractive, and therefore fit, partner would have carried a huge survival advantage. ©independent.co.uk

Keyword: Sexual Behavior; Evolution
Link ID: 14585 - Posted: 10.26.2010

By Floyd Skloot Oliver Sacks published his first book, “Migraine,’’ 40 years ago. A provocative mixture of scholarship, personal experience, and case studies, it approached the malady as experience rather than illness, viewing the patient in full human dimension and not simply a collection of symptoms, signs, and test results. The book showed Sacks’s gifts, even at the start of his career, for accurate description and fresh prose, such as his characterization of migraine’s hallucinatory aura as a “dance of brilliant stars, sparks, flashes.’’ Over his long career as a neurologist and writer, Sacks has addressed a range of subjects: “Awakenings’’ (1973) dealt with patients immobilized and silenced by sleeping sickness who were briefly returned to active function by the administration of a drug that failed to sustain its benefits; “Seeing Voices’’ (1989) was a journey into the world of the deaf; “Musicophilia’’ (2007) concerned the human passion for music. In all his work, Sacks has been fascinated by how the brain’s failures of function, its neuro-strangenesses, reveal essential truths about what makes us human. His books are populated by people — those with autism or Tourette syndrome or aphasia — whose experiences with and adaptations to neurological problems encourage us to think about our own perceptions of the world. From those earliest studies of migraine through his accounts of misperception in “The Man Who Mistook His Wife for a Hat’’ (1985) and congenital colorblindness in “The Island of the Colorblind’’ (1997), Sacks has returned to the subject of sight and the neurology of visual perception. Now in “The Mind’s Eye,’’ his 11th book, Sacks takes on the subject fully, offering seven essays about vision and what it is like when the sense of sight is radically changed or lost because of neurological damage. His exploration of this subject is deepened by personal experience, as Sacks’s own visual health becomes compromised. © 2010 NY Times Co.

Keyword: Vision
Link ID: 14584 - Posted: 10.26.2010

by Jessica Hamzelou Neurologists have found that the brain plaques associated with Alzheimer's can form when the proteins responsible are injected into the bellies of mice, suggesting that the guilty proteins can get from the body's periphery to wreak havoc in the brain. A protein called beta-amyloid makes up the brain plaques that accompany the disease. In 2006, Lary Walker at Emory University in Atlanta, Georgia, Mathias Jucker at the University of Tübingen in Germany and colleagues found that they could trigger Alzheimer's-like plaques by injecting samples of plaque-ridden brains into the brains of healthy mice. Now, Jucker and his colleagues at Tübingen have managed to create the same brain plaques by injecting the tissue elsewhere in the bodies of mice. The group used mice genetically modified to produce large amounts of beta-amyloid, meaning they develop brain plaques similar to those seen in Alzheimer's disease in people. When the mice were around 2 years old, the team removed some of their beta-amyloid-laden brain tissue and injected it into the peritoneum – the lining of the abdomen – of young transgenic mice. Another group of transgenic mice received an injection of healthy brain tissue from normal mice of the same age that had not developed plaques. Seven months later, before the mice had had a chance to develop plaques of their own accord, the team looked at the their brains. The mice injected with healthy brain tissue had normal-looking brains, but those injected with beta-amyloid-heavy tissue had developed full-blown plaques similar to those seen in people with Alzheimer's. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 14583 - Posted: 10.23.2010

By Emily Sohn New moms may feel their brain cells dying with every cumulative hour of sleep loss. But a new study offers hope. In the first months after giving birth, the study found, parts of a mother's brain may actually grow. Even better news, doting mamas who gushed the most about how special and perfect their babies were showed the most growth. The parts of the brain that grew are involved in motivation, reward behavior and emotion regulation. That suggests that, by reshaping itself, the post-partum brain motivates a mother to take care of her baby, and then feel happy and rewarded when she does. The findings may eventually help women who feel disconnected from their babies or even hostile toward them in the early months, said lead author Pilyoung Kim, a developmental psychologist, now at the National Institutes of Mental Health in Bethesda, Md. "We could maybe compare brain changes in mothers who were depressed or had problems bonding with their infants to normal mothers," said Kim, who was at Yale University when she did the work. "And we might be able to develop some kind of intervention programs to help mothers feel more rewarded about their parenting and their baby." During pregnancy and the post-partum period, women often feel their brains turning to mush. New moms report that they have trouble remembering things that they used to remember easily. It's such a common phenomenon that women often call it "Mommy Brain." Some research has even shown that women's brains shrink slightly during pregnancy. © 2010 Discovery Communications, LLC

Keyword: Sexual Behavior
Link ID: 14582 - Posted: 10.23.2010

by Patricia Churchland WHERE do moral values come from? Not from Plato's heaven, nor from any other. Aristotle, Confucius and Darwin all recognised valuing as a basic function of biological creatures generally, and moral valuing as a basic function of highly social and intelligent animals like humans. Until very recently, however, science could not explain how brains, built by gene networks interacting with the environment, give rise to morality. Natural selection being what it is, caring for others must serve the fitness of the animals involved. Evolutionary biologists have developed models to show how this might work, but it is only now that neuroscientists are catching the first glimpses of how altruistic behaviour happens in the brain. Morality seems to be shaped by four interlocking brain processes: caring, rooted in attachment to and nurture of offspring; recognition of others' psychological states, bringing the benefit of predicting their behaviour; problem-solving in a social context, such as how to distribute scarce goods or defend the clan; and social learning, by positive and negative reinforcement, imitation, conditioning and analogy. These factors result in the emergence of a conscience: a set of socially sanctioned responses to prototypical circumstances. © Copyright Reed Business Information Ltd.

Keyword: Emotions
Link ID: 14581 - Posted: 10.23.2010

by Martha J. Farah We have long known that moral character is related to brain function. One remarkable demonstration of this was provided by Phineas Gage, a 19th-century construction foreman injured in an explosion. After a large iron rod was blown through his head, destroying bits of his prefrontal cortex, Gage was transformed from a conscientious, dependable worker to a selfish and erratic character, described by some as antisocial. Recent research has shown that psychopaths, who behave antisocially and without remorse, differ from the rest of us in several brain regions associated with self-control and moral cognition (Behavioral Sciences and the Law, vol 26, p 7). Even psychologically normal people who merely score higher in psychopathic traits show distinctive differences in their patterns of brain activation when contemplating moral decisions (Molecular Psychiatry, vol 14, p 5). The idea that moral behaviour is dependent on brain function presents a challenge to our usual ways of thinking about moral responsibility. A remorseless murderer is unlikely to win much sympathy, but show us that his cold-blooded cruelty is a neuropsychological impairment and we are apt to hold him less responsible for his actions. Presumably for this reason, fMRI evidence was introduced by the defence in a recent murder trial to show that the perpetrator had differences in various brain regions which they argued reduced his culpability. Indeed, neuroscientific evidence has been found to exert a powerful influence over decisions by judges and juries to find defendants "not guilty by reason of insanity" (Behavioral Sciences and the Law, vol 26, p 85). © Copyright Reed Business Information Ltd.

Keyword: Emotions
Link ID: 14580 - Posted: 10.23.2010

By Amanda Chan If you're a guy who finds it hard to talk about your feelings, the problem might lie with your testosterone levels, a recent study suggests. A psychological condition called alexithymia is found in people who have an extraordinarily difficult time conveying emotions to others and interpreting others' feelings. Past studies have shown that alexithymia and depression are closely related, and the condition has long been associated with aging. Depression, low testosterone and erectile dysfunction are all known to become more common in men as they age. Researchers from Finland wanted to see if alexithymia is a result of aging itself, or if it is actually caused by other factors that typically come with aging, like a lower sex drive. In the study, nearly 1,400 men ages 25 to 65 filled out questionnaires during a three-year period, beginning in 1998, and reported difficulties they had in expressing thoughts and emotions, symptoms of depression and general life-satisfaction levels. Out of those 1,400 men, researchers chose 116, half who had symptoms of alexithymia and half who did not, and asked them to complete a follow-up survey and report their alcohol intake, smoking status, and other information, and were also given a blood test to check their testosterone levels, said study researcher Kirsi Honkalampi, a professor at the Kuopio Psychiatric Center in Finland. MyHealthNewsDaily Copyright © 2010.

Keyword: Hormones & Behavior; Emotions
Link ID: 14579 - Posted: 10.21.2010

By Carolyn Y. Johnson The black-and-white brain scans that have become a routine part of medicine reveal a curved gray structure folded around large lakes of white — a map that helps doctors diagnose, treat, and understand disease. But to some scientists, these images are crude and incomplete, akin to medieval maps of the world in which unexplored regions were filled in with sea monsters or dragons. “It’s like there’s a continent there, and we are nibbling along the shores,’’ said Dr. Van Wedeen, a physicist and radiologist at the Martinos Center for Biomedical Imaging at Massachusetts General Hospital. He is helping to lead an effort to develop a superscanner that can reveal that unknown territory and provide new insight into the brain. On a recent morning, Wedeen pulled up images created with the new technology, in which the lakes of white were crisscrossed by colorful, ropy bundles of fibers, revealing an elegant, three-dimensional architecture. Looking more like art than anatomy, these strands form the connections in the brain — the “connectome.’’ They are neural highways crucial for brain function, including thoughts, movements, and sensations. “This isn’t just statistical stuff, or mush, or steel wool, or chaotic spaghetti,’’ Wedeen said. “This is as important a structure as you’re ever going to meet, and this thing had to be designed by evolution.’’ © 2010 NY Times Co.

Keyword: Brain imaging
Link ID: 14578 - Posted: 10.21.2010

by Sara Reardon A pregnant mom who regularly chows down on cheeseburgers probably isn't doing her baby any good; she may even predispose him to obesity, according to some studies. But when pediatrician Sheau-Fang Ng noticed that her chubby child patients tended to have not just one but two overweight parents, she began to wonder: Could dad's habits be weighing in, too? She and her colleagues have now found the first direct evidence that a father's diet, not just his genes, can increase his offspring's risk of diabetes and other diseases, at least in rats. In a simple experiment, the researchers—based at the University of New South Wales in Sydney, Australia—fed normal male rats a diet consisting of more than 40% fat, the rodent equivalent of vending machine food. The animals quickly became obese. The rats' daughters, born from mothers of normal weight and fed a healthy diet, weren't fat, but they did show early signs of diabetes by the time they reached puberty. Not only did their insulin levels fail to rise in response to high glucose, the team reports online today in Nature, but their insulin-producing islet cells in the pancreas also expressed very different genes than do normal islet cells. In addition, many of the daughters were underweight at birth, which, in humans, often foretells obesity later in life. Sons of fat fathers showed some signs of diabetes, too, but to a much lesser extent than their sisters. Lead author Margaret Morris believes that the sons, too, would likely develop symptoms as they age or if they were fed a high-fat diet. © 2010 American Association for the Advancement of Science.

Keyword: Obesity; Development of the Brain
Link ID: 14577 - Posted: 10.21.2010

By Karl Deisseroth Despite the enormous efforts of clinicians and researchers, our limited insight into psychiatric disease (the worldwide-leading cause of years of life lost to death or disability) hinders the search for cures and contributes to stigmatization. Clearly, we need new answers in psychiatry. But as philosopher of science Karl Popper might have said, before we can find the answers, we need the power to ask new questions. In other words, we need new technology. Developing appropriate techniques is difficult, however, because the mammalian brain is beyond compare in its complexity. It is an intricate system in which tens of billions of intertwined neurons—with multitudinous distinct characteristics and wiring patterns—compute with precisely timed, millisecond-scale electrical signals, as well as with a rich diversity of biochemical messengers. Because of that complexity, neuroscientists lack a deep grasp of what the brain is really doing—of how specific activity patterns within specific brain cells ultimately give rise to thoughts, feelings and memories. By extension, we also do not know how the brain's physical failures produce distinct psychiatric disorders such as depression or schizophrenia. The ruling paradigm of psychiatric disorders—casting them in terms of chemical imbalances and altered levels of neurotransmitters—does not do justice to the brain's high-speed electrical neural circuitry. And psychiatric treatments have historically been largely serendipitous: helpful for many but rarely illuminating, and suffering from the same challenges as basic neuroscience. In a 1979 Scientific American article Nobel laureate Francis Crick suggested that the major challenge facing neuroscience was the need to control one type of cell in the brain while leaving others unaltered. Electrical stimuli cannot meet this challenge because electrodes are too crude a tool: they stimulate all the circuitry at their insertion site without distinguishing between different cell types, and their signals cannot turn off neurons with precision. © 2010 Scientific American,

Keyword: Miscellaneous
Link ID: 14576 - Posted: 10.21.2010

By ALAN SCHWARZ NORMAN, Okla. — Moments after her son finished practicing with his fifth-grade tackle football team, Beth Sparks examined his scuffed and battered helmet for what she admitted was the first time. She looked at the polycarbonate shell and felt the foam inside before noticing a small emblem on the back that read, “MEETS NOCSAE STANDARD.” “I would think that means it meets the national guidelines — you know, for head injuries, concussions, that sort of thing,” she said. “That’s what it would mean to me.” That assumption, made by countless parents, coaches, administrators and even doctors involved with the 4.4 million children who play tackle football, is just one of many false beliefs in the largely unmonitored world of football helmets. Helmets both new and used are not — and have never been — formally tested against the forces believed to cause concussions. The industry, which receives no governmental or other independent oversight, requires helmets for players of all ages to withstand only the extremely high-level force that would otherwise fracture skulls. The standard has not changed meaningfully since it was written in 1973, despite rising concussion rates in youth football and the growing awareness of how the injury can cause significant short- and long-term problems with memory, depression and other cognitive functions, especially in children. Copyright 2010 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 14575 - Posted: 10.21.2010

By John von Radowitz, PA A gene that helps drink go to your head has been discovered by scientists. As well as providing a cheap night out, it is believed to protect against alcoholism. Previous research has shown that people who react strongly to alcohol are less likely to become alcoholics. The gene, CYP2E1, provides the coded instructions for making an enzyme that breaks down alcohol. Scientists found that 10% to 20% of the population possess a particular version of the gene that causes them to get drunk easily. The first few drinks during a night out will leave these individuals feeling more inebriated than their friends. Drugs that enhance the effect of CYP2E1 could in future be used to sensitise people to alcohol before an evening's drinking - or even sober them up when they have had one too many, said the researchers. Scientists in the US investigated the genetics of 237 college student siblings who had one alcohol-dependent parent but were not alcoholics themselves. ©independent.co.uk

Keyword: Drug Abuse; Genes & Behavior
Link ID: 14574 - Posted: 10.21.2010

By Laura Sanders Researchers have pinpointed a region of the brain where scarcity of a key protein may contribute to depression. The new findings, appearing October 20 in Science Translational Medicine, may pave the way to treating some cases of depression with gene therapy. In the new study, researchers led by Michael Kaplitt of the Weill Cornell Medical College in New York City found that depressed people had lower than normal levels of a protein called p11 in the brain’s nucleus accumbens. This brain structure is important for reward, drug addiction and depression. Delivering the gene for the p11 protein to this region eliminated depression-like behavior in listless mice, the researchers showed. “We believe that low levels of p11 may be one of the causes of depression in at least some patients,” Kaplitt says. “If we can restore it to normal levels, we can potentially reverse the process.” Depression is notoriously difficult to treat. “It’s very hard to get people to remission and keep them well with the treatments currently available,” says psychiatrist Madhukar Trivedi of the University of Texas Southwestern Medical Center at Dallas. In a recent large-scale study, about 40 percent of patients with depression who received consistent treatment relapsed within a year. Developing new treatments like the one proposed in the new study is critical, he says. © Society for Science & the Public 2000 - 2010

Keyword: Depression; Genes & Behavior
Link ID: 14573 - Posted: 10.21.2010

By Richard Alleyne, Science Correspondent The popular belief that women's minds turn to mush during pregnancy and birth is completely wrong and their grey matter actually increases, they say. Research published by the American Psychological Association found that the brains of new mothers bulked up as they coped with the steep learning curve of dealing with a newborn. Mothers who gushed the most about their babies showed the greatest growth in key parts of the brain, it was found. The researchers at the National Institute of Mental Health in Maryland scanned the brains of 19 women who gave birth to 10 to boys and nine to girls. A comparison of images taken two to four weeks and three to four months after the women gave birth showed that grey matter volume increased by a small but significant amount in various parts of the brain. In adults, grey matter does not ordinarily change over a few months without significant learning, brain injury or illness, or major environmental change. The authors speculated that hormone levels and the need to cope with the challenges of a baby led to the increase in brain cells. The areas affected are involved with motivation – the hypothalamus -, reward and emotion processing – the amygdala – senses – parietal lobe – and reasoning and judgment – the prefrontal cortex. The findings were published in the journal Behavioural Neuroscience. © Copyright of Telegraph Media Group Limited 2010

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 14572 - Posted: 10.21.2010

By RONI CARYN RABIN At their first family therapy session, Rina Ranalli and her husband tried to coax their anorexic 13-year-old daughter to eat a bagel with cream cheese. What followed was a protracted negotiation. The girl said she would eat it only if she could have it plain, with nothing on it. The parents countered that they really wanted her to eat it with the cream cheese. Her last offer: she would eat half. “Does this happen at every meal?” the therapist, Daniel Le Grange, asked them, Ms. Ranalli recalled. He added gently, “It has to stop.” “It’s anorexic debate, and it’s really not helpful,” Dr. Le Grange said later in an interview. “I will usually turn to the parents and say: ‘Mom and Dad — it’s your decision what she has to eat. You have to make the choices for her, because the anorexia doesn’t allow her to think clearly.’ ” Unlike traditional treatments for anorexia nervosa in adolescents, in which the patient sees the therapist one on one, this kind of family-based treatment encourages parents to play a pivotal role in restoring their child’s weight while trying to avoid hospitalizations. It is a demanding program: for the first two weeks of treatment, at least one parent must be available around the clock to supervise meals and snacks, and monitor children between meals to make sure they do not burn off the calories with excessive exercise. Copyright 2010 The New York Times Company

Keyword: Anorexia & Bulimia
Link ID: 14571 - Posted: 10.19.2010

By CHRIS FILARDI Waking at 1,600 meters in the Solomons is like waking in the clouds. Cloud days begin with a vigil of sorts: a slow and deliberate ascent up a ladderlike trail through the tangles to a perch that hangs out into the gloaming heart of morning cloud surrounding the high ridges. At dawn, wind heaves up from the central caldera, shifting the heavy mist. Other than this mountain breath, there is little indication of anything beyond moss, wood and orchids splaying out everywhere along the limb holding me up. From this perch one can read the morning chorus of birdsong. Many bird species roost for the night at perches reflecting their distribution within a forest and then sing in a beautifully clocklike species-specific cadence at dawn. This awakening can disclose the presence and distribution of species that are otherwise seldom detected and, properly interpreted, can provide an incredible amount of information about a forest bird community. Mornings here I actually hear two choruses — one softly twittering in the mossy heights, and another, almost a din, rising from the crater floor far below. It is remarkable, indescribable really, hearing montane songs in the leafy tufts around my head unique to Kolombangara and reminiscent of Eurasia or North America, and simultaneously the blare of whistlers, monarch flycatchers, coucals, fantails and cuckoo-shrikes rising from tall hill forest nearly 1,100 meters below. Copyright 2010 The New York Times Company

Keyword: Animal Communication; Language
Link ID: 14570 - Posted: 10.19.2010

by Michael Balter Neandertals are looking sharp these days. Many researchers now credit our evolutionary cousins, once regarded as brutish and dumb, with "modern behavior," such as making sophisticated tools and fashioning jewelry, a sign of symbolic expression. But new radiocarbon dating at a site in France could mar this flattering view. The study concludes that the archaeological layers at the site are so mixed up that ornaments and tools once attributed to Neandertals could actually be the work of modern humans, who lived in the same cave at a later date. One prominent researcher even argues that this celebrated site, the Grotte du Renne (literally "reindeer cave") at Arcy-sur-Cure in central France, should now be eliminated from scientific consideration. "This key site should be disqualified from the debate over [Neandertal] symbolism," says Randall White, an archaeologist at New York University. But João Zilhão, an archaeologist at the University of Bristol in the United Kingdom who has often tussled with White and other researchers over the evidence from the Grotte du Renne, says that the new study "prove[s] the exact opposite of what [its] authors claim." The Grotte du Renne was excavated between 1949 and 1963 by the late French prehistorian André Leroi-Gourhan, who found 15 levels of hominid occupation ranging from about 45,000 to 28,000 years ago. This period includes the overlapping occupation of Europe by Neandertals, who show up about 130,000 years ago and disappear no later than 30,000 years ago, and modern humans, who arrived in Europe between 45,000 and 40,000 years ago and stayed for good. © 2010 American Association for the Advancement of Science.

Keyword: Evolution
Link ID: 14569 - Posted: 10.19.2010

By REUTERS LONDON (Reuters) — Starch grains found on 30,000-year-old grinding stones suggest that prehistoric humans may have dined on an early form of flatbread, contrary to their popular image as primarily meat eaters. The findings, published in The Proceedings of the National Academy of Sciences journal on Monday, indicate that Paleolithic Europeans ground down plant roots similar to potatoes to make flour, which was later whisked into dough. “It’s like a flatbread, like a pancake with just water and flour,” said Laura Longo, a researcher on the team, from the Italian Institute of Prehistory and Early History. “You make a kind of pita and cook it on the hot stone,” she said, describing how the team replicated the cooking process. The end product was “crispy like a cracker but not very tasty,” she added. The grinding stones, each of which fits comfortably into an adult’s palm, were discovered at archaeological sites in Italy, Russia and the Czech Republic. The researchers said their findings throw humankind’s first known use of flour back some 10,000 years, the previously oldest evidence having been found in Israel on 20,000-year-old grinding stones. Copyright 2010 The New York Times Company

Keyword: Evolution; Obesity
Link ID: 14568 - Posted: 10.19.2010