Many changes in the physical environment contributed to the evolution of these early humans.
Australopithecines comprise a genus of primitive hominids that resided in Eastern Africa about 4.2 million years ago. Many scientists think that some of the australopithecine species are direct ancestors to humans. Others believe that the Australopithecines represent a branch of hominids from which humans evolved, but are not directly related to humans. There several established taxonomic methods for classifying the australopithecines, but the four most frequently acknowledged species are Australopithecus afarensis, Australopithecus africanus, Australopithecus robustus, and Australopithecus boisei (Chardin). The species can be differentiated, because A. robustus and A. boisei have bigger bones and are more "robust" than A. afarensis and A.africanus (O'Neill).
Most species of the Australopithecus were not any more adept at using tools than modern primates. But, Australopithecus garhi seems to have been the most sophisticated, because its remnants have been discovered near tools and slaughtered animal carcasses, which suggests the advent of a highly antediluvian tool conception. This caused many scientists to infer that A. garhi must be the predecessor of the Homo genus, even though recent deductions held that A. ...Show more