Steve Connor Babies of older fathers are more likely to carry genetic mutations than those of younger fathers. And the mutations could lead to illnesses such as autism and schizophrenia in later life, a landmark study has shown. Scientists have, for the first time, counted the number of new mutations linked with a father's age at the time of conception and have concluded that older men are significantly more likely to have children with potentially harmful genetic changes. The results could explain previous studies showing that certain mental and developmental illnesses with strong genetic components tend to be more common among people whose fathers were older at the time of conception. Although the age of a child's mother has been linked with problems associated with chromosomal defects, such as Down's syndrome, there has been scant information about the contribution made by older fathers to the future health of their offspring. "These observations shed light on the importance of the father's age on the risk of diseases such as schizophrenia and autism," the researchers say in their study published in the journal Nature. The scientists found that a new-born baby's genome contains around 60 new small-scale mutations compared with its parents and that the actual number of new mutations carried by each child was strongly dependent on the age of the father, rather than the mother, at the time of conception. The researchers, led by Augustine Kong and Kari Stefansson of deCode Genetics in Reykjavik, calculated that a 20-year-old father transmits about 25 new mutations to his child while a 40-year-old man will pass on 65. © independent.co.uk

Keyword: Autism; Sexual Behavior
Link ID: 17196 - Posted: 08.25.2012

By Susan Milius Black bears, which live relatively solitary lives as adults, show an ability to learn concepts, a new study finds. Dave Allen Photography/Shutterstock American black bears that take computerized tests by pawing, nose-bumping or licking a touch screen may rival great apes when it comes to learning concepts. Using three zoo bear siblings as classroom subjects, comparative cognitive psychologist Jennifer Vonk of Oakland University in Rochester, Mich., and her colleagues presented pairs of pictures to the bears on a rugged computer screen and gave them food treats for pawing the image from a certain category. To demonstrate learning a concept, bears had to figure out what kind of picture would earn a treat and then pick that kind of image from a new set. One challenge, picking the portrait of a black bear instead of an image of a person, could be mastered by relying on a mix of visual clues such as furriness or snout shape. But picking out all the animals from non-animals — cars or landscapes, for example — required finding more abstract connections among pictures that didn’t look much at all alike. At least one of the three bears showed some capacity at each of the five levels tested, Vonk and colleagues report in an upcoming Animal Behaviour. Bear behavior has been “very underappreciated,” says comparative ethologist Gordon Burghardt of the University of Tennessee at Knoxville. “They’re very smart and they have large brains.” They also live relatively solitary lives, which make them an important contrast to the mostly social animals tested for complex mental capacities to date. © Society for Science & the Public 2000 - 2012

Keyword: Intelligence; Evolution
Link ID: 17195 - Posted: 08.25.2012

By Christine Gorman More than 25 years later details of the attack are still shocking: Sometime after 2 A.M. one Sunday morning in May 1987, Kenneth James Parks, then 23, left his house in a Toronto suburb and drove 23 kilometers to the apartment of his wife's parents. He got out of the car, pulled a tire iron out of the trunk and let himself into the older couple's home with a key they had given him. Once inside, he struggled with and choked his father-in-law, Dennis Woods, until the older man fell unconscious and then struggled with and beat his mother-in-law, Barbara Ann Woods, stabbing her to death with a knife from her kitchen. Parks then got back into his car, drove to a nearby police station and announced to the startled officers on duty, "I think I have killed some people." For several hours before the Toronto man left his home, however, and throughout the course of the attack, Parks was asleep and therefore not criminally responsible for his actions, according to five doctors and the defense lawyer at his 1988trial for the murder of Barbara Ann and the attempted murder of Dennis. After deliberating for nine hours, the jury agreed and Parks was set free. Although prosecutors at the time considered the defense "ludicrous" and appealed the judge's decision to allow the jury to consider a sleepwalking defense, the Canadian Supreme court upheld the original ruling in 1992. Even the sleep specialist who was first brought in as a consultant on the case was initially skeptical that a sleepwalker could have undertaken such a series of complex behaviors—including safely driving through three traffic lights and portions of an express highway—before attacking anyone. After all, most people who strike out in their sleep usually injure themselves or the person sleeping next to them—not someone 23 kilometers away. But further examination showed that the tragedy was not, as it had first seemed, a clear-cut case of murder. © 2012 Scientific American,

Keyword: Sleep; Aggression
Link ID: 17194 - Posted: 08.22.2012

By DOUGLAS QUENQUA Moleendo Stewart can’t say for sure what’s caused his lifelong sleeping problems. But he has his suspicions. There’s the childhood spent in loud, restless neighborhoods in Miami. “You hear people shooting guns all night, dealing drugs,” said Mr. Stewart, 41, who lives in the East Flatbush section of Brooklyn. He also cites his weight, 260 pounds, down from a peak of 310. Sleep experts would point to another factor working against Mr. Stewart: He is a black man. The idea that race or ethnicity might help determine how well people sleep is relatively new among sleep researchers. But in the few short years that epidemiologists, demographers and psychologists have been studying the link, they have repeatedly come to the same conclusion: In the United States, at least, sleep is not colorblind. Non-Hispanic whites get more and better-quality sleep than people of other races, studies repeatedly show. Blacks are the most likely to get shorter, more restless sleep. What researchers don’t yet know is why. “We’re not at a point where we can say for certain is it nature versus nurture, is it race or is it socioeconomics,” said Dr. Michael A. Grandner, a research associate with the Center for Sleep and Neurobiology at the University of Pennsylvania. But when it comes to sleep, “there is a unique factor of race we’re still trying to understand.” © 2012 The New York Times Company

Keyword: Sleep; Stress
Link ID: 17193 - Posted: 08.22.2012

Analysis by Sheila Eldred Behavioral control and decision-making take part in different regions of the brain's frontal lobe, new research shows The study effectively created a map of the frontal lobes, making it possible for patients with brain injuries to get an accurate prognosis early in treatment. "That knowledge will be tremendously useful for prognosis after brain injury," Ralph Adolphs, Bren Professor of Psychology and Neuroscience at Caltech and a coauthor of the study published in this week's issue of the Proceedings of the National Academy of Sciences (PNAS), said in a press release. "Many people suffer injury to their frontal lobes -- for instance, after a head injury during an automobile accident -- but the precise pattern of the damage will determine their eventual impairment," he added. When you're making a decision, several different parts of the brain might be activated. How a person functions after a brain injury depends on precisely where a brain injury occurs. Other parts of the brain might compensate, allowing the person to function typically, or the person might be left with a lifelong hardship in making decisions. "We can use our lesion maps and compare the location of damaged brain areas in new patients," Jan Glascher, lead author of the study and a visiting associate in psychology at Caltech, said in an email interview. "This way we can predict what impairments these new patients will likely have. This can facilitate medical diagnoses and spark ideas for treatment strategies." © 2012 Discovery Communications, LLC.

Keyword: Attention
Link ID: 17192 - Posted: 08.22.2012

by Hannah Krakauer Kanzi the bonobo continues to impress. Not content with learning sign language or making up "words" for things like banana or juice, he now seems capable of making stone tools on a par with the efforts of early humans. Eviatar Nevo of the University of Haifa in Israel and his colleagues sealed food inside a log to mimic marrow locked inside long bones, and watched Kanzi, a 30-year-old male bonobo chimp, try to extract it. While a companion bonobo attempted the problem a handful of times, and succeeded only by smashing the log on the ground, Kanzi took a longer and arguably more sophisticated approach. Both had been taught to knap flint flakes in the 1990s, holding a stone core in one hand and using another as a hammer. Kanzi used the tools he created to come at the log in a variety of ways: inserting sticks into seams in the log, throwing projectiles at it, and employing stone flints as choppers, drills, and scrapers. In the end, he got food out of 24 logs, while his companion managed just two. Perhaps most remarkable about the tools Kanzi created is their resemblance to early hominid tools. Both bonobos made and used tools to obtain food – either by extracting it from logs or by digging it out of the ground. But only Kanzi's met the criteria for both tool groups made by early Homo: wedges and choppers, and scrapers and drills. © Copyright Reed Business Information Ltd.

Keyword: Evolution; Language
Link ID: 17191 - Posted: 08.22.2012

by Gilead Amit The bath of cells in avian eyes could prolong a delicate quantum state that helps to explain how some birds navigate using Earth's magnetic field. It is thought that light reacts with receptors in the birds' eyes to produce two molecules with unpaired electrons, whose spins are linked by a special state called quantum entanglement. If the relative alignment of the spins is affected by Earth's magnetic field, the electron pair can cause chemical changes that the bird can sense. In 2009, researchers at the University of Oxford calculated that such entanglement must last for at least 100 microseconds for the internal compass to work. But how the sensitive state of quantum entanglement could survive that long in the eye was a mystery. Calculations by Zachary Walters of the Max Planck Institute for the Physics of Complex Systems in Dresden, Germany, now show that interactions with cells in the bird's eye allow the electron pairs to stay entangled for longer through a dampening effect. Rather like the way a car with stiff shock absorbers takes longer to stop bouncing after going over a bump, the signal from the electron pair dies away more slowly under strong interactions with the cellular bath. Predicting exactly how long entanglement is sustained won't be possible until the mechanism is better understood, says Walters. But he believes there's a good chance his model could account for the 100 microseconds. © Copyright Reed Business Information Ltd

Keyword: Vision
Link ID: 17190 - Posted: 08.22.2012

By Bruce Bower All too often, high school students have to decide whether to join in on gulping down booze with the cool kids or lighting up a cigarette with parking-lot rebels. A new study suggests that genetics plays a role in the likelihood that some teens will succumb to this kind of peer pressure. Adolescents generally report drinking and smoking a lot in schools with high levels of such behavior, and doing so relatively infrequently in schools with low levels of substance use. These trends were stronger in teens with two copies of a short version of a gene called 5HTT than peers with two long versions, sociologist Jonathan Daw of the University of Colorado Boulder reported August 18 at the American Sociological Association’s annual meeting in Denver. Teens who had inherited one long and one short gene reported rates of alcohol and cigarette use that fell in between those of the other two groups, regardless of how much substance use occurred at their schools, Daw and his colleagues found. The 5HTT gene helps regulate transmission of serotonin, a chemical messenger in the brain. Daw’s team likens teens with the two short versions of the gene to social chameleons, more likely to conform to smoking and drinking styles of students around them than teens with one or no short variants. “Our data suggest that, alongside many other influences on adolescent substance use, genetics partly underlie individuals’ susceptibility to peer smoking and drinking,” Daw says. © Society for Science & the Public 2000 - 2012

Keyword: Drug Abuse; Genes & Behavior
Link ID: 17189 - Posted: 08.22.2012

By Christie Wilcox Music has a remarkable ability to affect and manipulate how we feel. Simply listening to songs we like stimulates the brain’s reward system, creating feelings of pleasure and comfort. But music goes beyond our hearts to our minds, shaping how we think. Scientific evidence suggests that even a little music training when we’re young can shape how brains develop, improving the ability to differentiate sounds and speech. With education funding constantly on the rocks and tough economic times tightening many parents’ budgets, students often end up with only a few years of music education. Studies to date have focused on neurological benefits of sustained music training, and found many upsides. For example, researchers have found that musicians are better able to process foreign languages because of their ability to hear differences in pitch, and have incredible abilities to detect speech in noise. But what about the kids who only get sparse musical tutelage? Does picking up an instrument for a few years have any benefits? The answer from a study just published in the Journal of Neuroscience is a resounding yes. The team of researchers from Northwestern University’s Auditory Neuroscience Laboratory tested the responses of forty-five adults to different complex sounds ranging in pitch. The adults were grouped based on how much music training they had as children, either having no experience, one to five years of training, or six to eleven years of music instruction. © 2012 Scientific American

Keyword: Hearing; Development of the Brain
Link ID: 17188 - Posted: 08.22.2012

Kathryn Lougheed A chemical in llama semen responsible for inducing ovulation in females has been identified and, surprisingly, it is a protein already known for its role in promoting the growth and survival of nerve cells in many species1. The protein — nerve growth factor (NGF) — is also found in human semen, suggesting that it may play a previously unsuspected role in human fertility. Whereas many animals, including humans, cattle and mice, produce eggs as part of a cycle of spontaneous ovulation, others — including llamas, camels, rabbits and koalas — are ‘induced ovulators’ that need a chemical stimulus. In 2005, Gregg Adams, a veterinary surgeon and reproductive scientist at the University of Saskatchewan in Saskatoon, Canada, and his colleagues showed that in llamas, the stimulus was in the seminal fluid2. In the latest study, published this week in the Proceedings of the National Academy of Sciences1, Adams led a team that identified the chemical as NGF. Although human women do not require NGF in semen to ovulate, Adams says that the protein could still have a direct effect on human fertility. Earlier this year, he published a paper3 showing that llama seminal fluid shortens the ovulation cycles of cows and seems to stimulate the development of the corpus luteum — a structure inside the ovaries that forms after an egg has been released and secretes hormones vital to pregnancy. In some cases, NGF could explain why some couples find it difficult to conceive, says Adams. A couple could have fertility problems if either the man failed to produce enough NGF in his semen or the woman lacked the receptors to detect and respond to it, he says. © 2012 Nature Publishing Group

Keyword: Sexual Behavior
Link ID: 17187 - Posted: 08.22.2012

By Brett Israel and Environmental Health News A widely used pesticide – banned in homes but still commonly used on farms – appears to harm boys’ developing brains more than girls’, according to a new study of children in New York City. In boys, exposure to chlorpyrifos in the womb was associated with lower scores on short-term memory tests compared with girls exposed to similar amounts. The study is the first to find gender differences in how the insecticide harms prenatal development. Scientists say the finding adds to evidence that boys’ brains may be more vulnerable to some chemical exposures. “This suggests that the harmful effects of chlorpyrifos are stronger among boys, which indicates that perhaps boys are more vulnerable to this type of exposure,” said Virginia Rauh, a perinatal epidemiologist at Columbia University and co-author of the study published in July. Chlorpyrifos is an organophosphate insecticide, a powerful class of pesticide that has toxic effects on nervous systems. It was widely used in homes and yards to kill cockroaches and other insects, but in 2001 the U.S. Environmental Protection Agency banned its residential use because of health risks to children. Since then, levels inside U.S. homes have dropped [PDF], but residue remains in many homes. In addition, many developing countries still use the pesticide indoors. Known by the Dow trade name Lorsban, chlorpyrifos is still sprayed on some crops, including fruit trees and vegetables, and also is used on golf courses and for mosquito control. About 10 million pounds of chlorpyrifos are applied to agricultural fields annually, according to the EPA. © 2012 Scientific American,

Keyword: Neurotoxins; Learning & Memory
Link ID: 17186 - Posted: 08.22.2012

Posted by Kathleen Raven Families with autistic children must navigate a condition where questions outnumber the answers, and therapies remain sparse and largely ineffective. A clinical trial being conducted by the Sutter Neuroscience Institute in Sacramento, California to address this situation began recruiting participants today for a highly experimental stem cell therapy for autism. The institute plans to find 30 autistic children between ages 2 and 7 with cord blood banked at the privately-run Cord Blood Registry, located about 100 miles west of the institute. Already one other clinical trial, with 37 total participants between ages 3 and 12 years old, has been completed in China. The researchers affiliated with Beike Biotechnology in Shenzhen, the firm that sponsored the study, have not yet published any papers from that the trial, which used stem cells from donated cord blood. Mexican researchers are currently recruiting kids for yet another type of autism stem cell trial that will harvest cells from the participant’s fat tissue. But for each of these officially registered trials, many more undocumented stem cell therapy treatments take place for clients who are willing to pay enough. “Our research is important because many people are going to foreign countries and spending a lot of money on therapy that may not be valid,” says Michael Chez, a pediatric neurologist and lead investigator of the study at Sutter. © 2012 Nature Publishing Group,

Keyword: Autism; Stem Cells
Link ID: 17185 - Posted: 08.22.2012

By Jonathan Ball BBC News Young male fruit flies learn the smell of a receptive female to avoid wasting their sexual efforts, research shows. Promiscuous male flies initially court all females, but are rejected by those who have already mated. It is clear that the flies eventually learn to spot mated females, but just how they do has remained a mystery. Research published in Nature suggests that they smell a chemical signal called a pheromone left by other males during mating. The studies were performed using the common fruit fly - Drosophila melanogaster. This insect is used widely in genetic studies because they are easy to grow and they reproduce quickly - but principally because it is possible to generate and study flies that possess changes - or mutations - in their genetic material. In the study, Prof Barry Dickson and colleagues from the Research Institute of Molecular Pathology in Vienna, Austria, performed a series of studies to identify the mechanism that led to this change in behaviour in older flies. Using complementary approaches, the team showed that a pheromone called cVA was responsible. Pheromones are substances produced by one individual which modify the behaviour of another. They are widely known to work in the animal kingdom to warn of danger, define territories or attract mates. Mosquito The finding could be used for the control of other insects such as mosquitoes, which spread malaria BBC © 2012

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 17184 - Posted: 08.20.2012

A Brazilian construction worker has survived after a 2m (six-foot) steel rod fell from above and pierced his head, doctors who treated him say. Eduardo Leite was taken to a Rio de Janeiro hospital, where the rod was removed after five hours of surgery. The doctors said Mr Leite, who is expected to spend some two weeks under their care, had responded well to surgery. He narrowly escaped partial paralysis and loss of an eye, they added. The rod is said to have fallen from the fifth floor of a building under construction. It pierced Mr Leite's hard hat, then the back of his skull, before exiting between his eyes. Luiz Alexandre Essinger, chief of staff at the Miguel Couto hospital, said Mr Leite was conscious when he arrived there and explained what had happened to him. "He was taken to the operating room, his skull was opened, they examined the brain and the surgeon decided to pull the metal bar out from the front in the same direction it entered the brain," he said. Mr Leite had "few complaints" after the surgery, Mr Essinger added, saying "it really was a miracle" that he survived. BBC © 2012

Keyword: Miscellaneous
Link ID: 17183 - Posted: 08.20.2012

By Melissa Dahl, NBC News You lost 15 pounds! And gained it back. And lost it! And gained it back. It's been this way for years, so long that you've begun to believe that you've mucked up your metabolism, not to mention your odds of ever taking that weight off permanently. But take heart, yo-yo dieters: A new study suggests that your history of gaining and losing, gaining and losing, actually doesn't screw up your metabolism, nor does it wreck your chances at future weight loss attempts. The new research, recently published in the journal Metabolism, provides some hopeful news for those who've tried a series of diet fads and serious programs -- Weight Watchers, paleo, cleanses -- only to put that weight right back on. Advertise | AdChoices "Just because you didn't reach or keep to a goal before doesn't mean you won't succeed if you try again," says Anne McTiernan, a researcher at Fred Hutchinson Cancer Research Center in Seattle, whose work is primarily concerned with how diet and exercise affect a person's cancer risk. Up to 40 percent of people in Westernized countries like the U.S. have a tendency toward weight cycling, as it's academically termed. Previous studies have turned up mixed findings on the ways our bodies and behavior changes after repeated periods of weight loss and gain. But it's a commonly held belief that yo-yo diets increase our likelihood of gaining weight over time. Still, few studies have been able to prove this, so McTiernan set out to do so. © 2012 NBCNews.com

Keyword: Obesity
Link ID: 17182 - Posted: 08.20.2012

by Sara Reardon The carnival trick of guessing a person's age has just gained a lot more rigour. A new brain imaging technique can predict a child's age to within a year. The technique could be useful for determining whether a child is developing normally, or confirm that a young person is the age they say they are. There is no doubt that children of the same age often have vast differences in their maturity and mental ability, says Timothy Brown of the University of California in San Diego. But what hasn't been clear is how much of that difference is psychological and how much is biological. To simplify the question, Brown and his colleagues looked at brain structure rather than brain activity. Working with 10 hospitals in different parts of the US, they recruited 885 children and young adults between the ages of 3 and 20. They ensured that the participants represented many different races, socioeconomic statuses and education levels. The group performed structural magnetic resonance imaging (MRI) on the young peoples' brains. The images showed features such as the size of each brain region, the level of connectivity between neurons, and how much white matter was insulating the neurons. By putting all these features together in an algorithm, the researchers formed a picture of what the average brain looks like at each year of childhood. Different areas and features of the brain varied between individuals, but the algorithm correctly predicted a child's age to within a year in 92 per cent of cases. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Brain imaging
Link ID: 17181 - Posted: 08.18.2012

By Jason G. Goldman The largest fish in the ocean is the whale shark (Rhincodon typus). This massive, migratory fish can grow up to twelve meters in length, but its enormous mouth is designed to eat the smallest of critters: plankton. While the biggest, the whale shark isn’t the only gigantic filter-feeding shark out there: the basking shark and the megamouth shark also sieve enormous amounts of the tiny organisms from the sea in order to survive. While scientists like Al Dove and Craig McClain (of Deep Sea News) are learning more and more about the basic biology and behavior of these magnificent creatures, other scientists are busy investigating their neuroanatomy. A few years ago, Kara E. Yopak and Lawrence R. Frank from the University of California in San Diego got their hands on two whale shark brains from an aquarium, and put them into an MRI scanner. But they weren’t just interested in imaging the brains of the whale sharks. What they wanted to know was how the organization of whale shark brains compared to the brains of other shark species for which scientists had previously obtained neuroanatomical data. Would the brains of two species be more similar if they shared a recent evolutionary ancestor, and were therefore more genetically related? Or would shark brains be more similar among species that shared a similar lifestyle, such as those that patrol the middle and surface of the water column (pelagic sharks, such as the great white, oceanic whitetip, blue, mako, and whale sharks) versus those that live along the sea floor (benthic sharks, such as the nurse and cat sharks). Or perhaps the brains of sharks would be grouped according to their habitat, such as those that live in coastal waters, around reefs, or in the open ocean. Maybe sharks brains ought to be grouped according to behavioral specialization, such as hunting methods. Answers to these questions could shed some important light on brain evolution, both in sharks as well as more generally. © 2012 Scientific American

Keyword: Evolution; Brain imaging
Link ID: 17180 - Posted: 08.18.2012

Sandrine Ceurstemont, Most of us would probably find it difficult to remember everything we did yesterday. But for a small group of people with near-perfect memory, autobiographical events from decades ago can be recalled just as easily as scrolling through a DVD. Sean Conlon, a food and beverages director from Baltimore, Maryland, and Frank Healy, a counsellor based in Pennsylvania, are two of about 30 people now confirmed to possess highly superior autobiographical memory. In this video, you can watch them recall life events from specific dates without prior preparation. Since the dates coincide with historical events, we were able to check that they weren't making it up. The two men recently had their brain scanned by memory researcher James McGaugh and colleagues from the University of California, Irvine, whose work is now revealing differences in certain memory regions for people with the ability. The team also found that super-memorisers share some of the hallmarks of obsessive compulsive disorder (OCD). Conlon claims that he doesn't have obsessive tendencies, other than being preoccupied with his past. Healy, however, admits that he's quite germ-phobic: at restaurants he will go and wash his hands as soon as he places his order. Both men have found their memory to be advantageous in their jobs. "It helps me if I have a client who stops therapy for a year or two and then returns," says Healy. "I'm instantly able to remember their birthday, their issues and everything about them." © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory; OCD - Obsessive Compulsive Disorder
Link ID: 17179 - Posted: 08.18.2012

By Bruce Bower A callous, manipulative psychopath convicted of a brutal crime can count on a long prison stint. But a judge may issue a slightly shorter sentence if presented with a biological explanation for the criminal’s psychopathic personality. Supplying judges with scientific evidence about suspected brain deficits in psychopathy led to a reduction in prison sentences from about 14 years to 13 years, researchers report in the Aug. 17 Science. The results come from a nationwide, online survey of state judges given a hypothetical scenario about a psychopath convicted of what lawyers call aggravated battery. Judges taking the survey tended to view psychopathic criminals as dangerous, whether or not scientific evidence was introduced, say psychologist Lisa Aspinwall, lawyer Teneille Brown and philosopher James Tabery, all of the University of Utah in Salt Lake City. A hypothetical psychopath in the new study got sent to the slammer for longer than the average nine-year sentence given to non-psychopaths found guilty of aggravated battery in real courts. Aspinwall and her colleagues informed judges that clinicians use psychopathy — which is not an official psychiatric diagnosis — to refer to individuals who are impulsive, emotionally shallow, outwardly charming, lacking in empathy or remorse, chronic liars and callous manipulators (SN: 12/9/06, p. 379). Judges were told that psychopathy is incurable. © Society for Science & the Public 2000 - 2012

Keyword: Aggression
Link ID: 17178 - Posted: 08.18.2012

by Michael Marshall Big and strong predators are dangerous enough, but clever ones are the worst. There's nothing more annoying than realising you've been outwitted in the seconds before you're disembowelled. Killer whales are some of the smartest predators on Earth. They can climb onto beaches to catch sea lions, stun fish by slapping them with their tails, and create waves to knock seals off ice floes. That might be because they learn from each other. They are one of the few animals that can imitate behaviours that they haven't seen before, and they are ferociously quick students. Despite their name, killer whales are actually dolphins – albeit rather large ones. Populations in different areas are quite dissimilar, and genetic evidence suggests that there are actually several species. A key difference between populations is that they target different prey, using different techniques. In the Crozet Islands in the Indian Ocean, whales strand themselves on beaches to hunt southern elephant seals. In Patagonia, they hunt sea lions in the same way. Beaching oneself on purpose is unusual, and it takes young killer whales years to get the hang of it. Even at five or six years old, they often need their mothers' help to get back off the beach. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory; Aggression
Link ID: 17177 - Posted: 08.18.2012