Final answer:
Molecular evidence supports the "Out of Africa" model as the division between humans and African apes, indicating that humans and chimps diverged 5 to 7 million years ago. Modern humans emerged in Africa around 200,000 years ago and spread globally 100,000 years ago.
Step-by-step explanation:
Molecular evidence indicates that the division between humans and African apes took place due to humans evolving from a common ancestor shared with Australopithecus about two million years ago. Genetic studies suggest that humans and chimpanzees diverged between 5 and 7 million years ago. The most commonly accepted model of human evolution, the "Out of Africa" model, proposes that modern humans first emerged in Africa around 200,000 years ago and then spread out of Africa to populate different parts of the globe around 100,000 years ago, replacing other human species.
An alternative to this is the multiregional evolution model, which proposes simultaneous evolution from Homo erectus to Homo sapiens in various regions of the world. However, this latter model is less supported by genetic data, which indicates that modern humans have a much closer genetic link to populations within Africa, supporting the "Out of Africa" model.
A key fossil in this discussion is Sahelanthropus tchadensis, which lived approximately 7 million years ago and may represent the last common ancestor of humans and chimpanzees. During the subsequent millions of years, significant evolutionary changes occurred, such as bipedalism evidenced by Australopithecus, and eventually leading to the genus Homo, which includes modern humans, Homo sapiens.