The adoption of bipedalism by the hominids: A new hypothesis

It is represented that hominids, from the earliest Australopithecines to modern man, exhibit modifications to the post-cranial structures that are more consonant with this hypothesis than with the interpretation that the modifications were directed initially and principally towards bipedalism.

Abstract

The hypothesis is advanced that the habitual adoption of the bipedal stance and of bipedal locomotion in the hominids arose from the development of a defence mechanism, namely, the throwing of stones. It is argued that for stone-throwing to become an effective weapon, modifications to the whole post-cranial skeleton and musculature, as well as to the central nervous system are required; including the development of a low centre of gravity and a «launching platform» of relatively high mass. It is represented that hominids, from the earliest Australopithecines to modern man, exhibit modifications to the post-cranial structures that are more consonant with this hypothesis than with the interpretation that the modifications were directed initially and principally towards bipedalism. Such an interpretation is shown to create several anomalies which disappear when viewed in the context of the stated hypothesis. The importance of the hypothesis for the evolution of Homo and especially for his brain and higher thought processes is commented upon.