tag:blogger.com,1999:blog-5255439.post-1101140088435584532004-11-22T10:57:00.000-05:002004-11-22T11:14:48.436-05:00Were humans <a href="http://www.newscientist.com/news/news.jsp?id=ns99996681">born to run</a>?: <blockquote>Proponents of the theory say that <a href="http://news.bbc.co.uk/2/hi/health/4021811.stm">long-distance running</a> may be an even more significant evolutionary adaptation than bipedal walking, an ability which may have emerged with the appearance of the first hominids <a href="http://www.newscientist.com/news/news.jsp?id=ns99996353">some 6 million years ago</a>. It is true that we cannot keep up with the fastest four-legged mammals. The speediest humans can sprint at barely 10 metres per second for just 15 seconds, whereas horses and greyhounds can gallop twice as fast for many minutes. Yet anthropologists, in focusing on this lack of short-term speed, have overlooked how well adapted we are for endurance running, according to biologist Dennis Bramble at the University of Utah, and his colleague Dan Lieberman of Harvard University. "Our legs are full of tendons that are not present in other primates," says Lieberman. "You don’t use your Achilles tendon when you walk," he says, but it is essential for running. Our buttock muscles, whose large size is a distinctly human attribute, are also vital for running, as they help stabilise the trunk and prevent it pitching forwards. These muscles too are barely used in walking. Runners also need to keep their bodies cool, which could explain our large number of sweat glands and largely hairless skin. Many of these adaptations appeared with Homo erectus around 2 million years ago. The long legs, short arms and low shoulders of H. erectus and later humans match the demands of running, while in contrast, the limb proportions of the earlier australopithecines were much closer to those of modern chimps, say Lieberman and Bramble.</blockquote> Diarmidhttp://www.blogger.com/profile/16648277543055227127noreply@blogger.com