Born to Run: the Human Advantage

An interesting theory on how human's capacity to run long distances may have played a role in evolution.

http://www.nytimes.com/2009/10/27/health/27well.html?_r=1

Most mammals can sprint faster than humans — having four legs gives them the advantage. But when it comes to long distances, humans can outrun almost any animal. Because we cool by sweating rather than panting, we can stay cool at speeds and distances that would overheat other animals. On a hot day, the two scientists wrote, a human could even outrun a horse in a 26.2-mile marathon.