Australopithecines and Homo, Essay Example

There are two models that exist in reference of when the spit between the Australopithecines and Homo occurred. The first model proposes a split of between three and two million years ago. The second model proposes a split between the two groups 1.9 and 1.4 million years ago. Both of these splits seem to be, from all anthropological accounts, mostly of a reproductive nature; however, there are certainly adaptations and environmental influences that would have caused the split to happen.

The most significant features of the split between the australopithecines and the Homo can be seen in the size of the head. Early ‘humans’, or the Homo genus began to develop larger brains and smaller faces with proportionately smaller teeth and jaws than their counterparts. They also became better at adapting to their survival by become more ‘gracile’ than did the australopithecines.

The early hominids that were reconstructed were considered to be bipedal, but small-brained. These groups were A. afarensis and A. africanus and had a lighter build than did the other species during that time period. They are now considered to be the more gracile species and are regarded by many anthropologists as direct human ancestors.

In keeping with the adaptation process, A. afarensis and A. africanus had smaller jaws, molars, and premolars, which gave the assumption they kept to a generalized diet, while the australopithecines were more large-toothed and had heavier skeletons and more prominent jaws, molars, and premolars which would aid in the chewing of rougher materials. They also had larger and sharper canine like teeth, which would have also aided chewing rougher materials.