New fossil evidence seems to confirm that a key ancestor of ours could walk upright consistently - one of the major advances in human evolution.

The evidence comes in the form of a 3.2 million-year-old bone that was found at Hadar, Ethiopia.

Its shape indicates the diminutive, human-like species Australopithecus afarensis had arches in its feet.

Arched feet, the discovery team tells the journal Science, are critical for walking the way modern humans do....