Baby We Were Born To Run

It all started about four and a half million years ago, when some striving Australopithecus decided that it would be more fashionable to walk upright than to crawl around like some kind of quadriped. Since then, anthropologists say, the human skeleton, muscles, tendons and ligaments have been evolving into an efficient and elegant running machine. The New York Times reports on a new theory that the development of our sleek new running physique took much longer than previously thought.