Walking and running upright on two feet as humans do requires some specialized adaptations of the skeleton and muscles. Modern human anatomy has built on the strengths and the weaknesses of a body ...

had been made by some of the first upright-walking hominids. An almost unimaginable sequence of events preserved what paleontologist Ian Tattersall calls a fossil of human behavior -- prehistoric ...

The first human-like traits to appear in the hominin fossil record are bipedal walking and smaller, blunt canines.