A History of Human Ancestors. What theories make up what we know about our earliest ancestors? What are the characteristics of our different homo ancestors?

Stringer and Brauer propose in their "Out of Africa" hypothesis that Homo ergaster, H. heidelbergensis, and H. sapiens emerged from Africa. According to their model, H. ergaster branched out and led to the rise of H. erectus in Asia; whereas H. heidelbergensis spread more of its species to Europe and possibly Asia. Homo sapiens were thought to have emerged right out of Africa, and then spread worldwide.
The recent discovery of the H. antecessor fossils at the Gran Dolina and Sima de los Huesos sites in Spain, however, conflicted with the "Out of Africa" model. The remains of H. antecesso…