ape-faced human ancestor walked steadily on two feet. To get a picture of how Lucy's species, Australopithecus afarensis, moved, scientists compare fossils to the bones of modern humans ...

From the heart's blood-pumping ability to the liver's filtering power, each component of the human ... your anatomy with the answers to these questions, plus a few bonus facts about your bones ...

Modern human anatomy has built on the strengths ... toppling to one side when all our weight is on one foot in mid-stride. Chimps have thigh bones that do not slope inward to the knee like ours ...