Overview
This chapter applies much of what has already been discussed to a description and analysis of what we know about the evolution of the primates in general and the early hominids in particular. The complex fossil record of the prehominid primates is presented fairly briefly, more to give a narrative summary and set the stage for what's to come than to delve into the myriad details and points of view.The centerpiece of the chapter is an extended discussion of the beginnings of hominid evolution and the importance of bipedalism, the first, and the defining hominid trait (although with the plethora of new finds one has to wonder if bipedalism is really exclusive to our evolutionary line). The scientific method is applied to the question of bipedalism by describing several hypotheses and then examining the data and logic in their support. The question of when, how, and why bipedalism evolved is, of course, far from settled, but this discussion should give students a good idea of just how science operates.
The early evolution of hominids is covered, both before and after the bipedalism section, with, again, an attempt to make a complex and contentious topic as clear and simple as possible. Here, however, I do go into some detail about anatomy and different points of view. With all the new material on very early hominids coming out of Africa , it is likely that some updating will be needed. The chapter ends with a section on how various authorities have suggested all the fossil forms are related.