Proceedings of the National Academy of Sciences Published: 15 June, 2011
The following is an excerpt from the article, (link above) which explores questions as to the origin of “Homo” species. I’m including it because, although the Out of Africa folks executed a remarkable marketing campaign in the media, which elevated the theory to a slam-dunk in popular science, publicity is not proof.
In the most parsimonious version of the “outside of Africa” scenario for the origin of Homo, H. erectus would have evolved from a H. habilis-grade hominin either in Asia or in Southeast Asia, and then H. erectus would have migrated to Africa some time before 1.87 Ma. This scenario is consistent with the aspects of the morphology of the Dmanisi and the Liang Bua hominins that are more primitive than the condition seen in H. erectus sensu stricto. This primitive morphology is one of stumbling blocks for a “within Africa” scenario for the origin of H. erectus taxon, for it would mean the migration out of Africa of two hominins, first a H. habilis-grade taxon then H. erectus sensu stricto. Another stumbling block for an ancestor-descendant relationship between H. habilis and H. erectus sensu stricto within Africa is that both the ancestor and the descendant overlap in time in East Africa for several hundred thousand years (5).