ABSTRACT
Since the fovea is typical of animals that are active during the day, its absence implies that early primates were probably nocturnal. Moreover, brain size estimates of some fossil hominins are higher than those of monkeys and apes. Changes in the position of the face are correlated with changes in brain size, whereas canine reduction is probably related to less intense male-male competition derived from weak polygyny. With these caveats in mind, the evidence reviewed in the rest of the chapter suggests the following: Biogeography, and Age. All the early fossil specimens that provide good evidence of bipedalism were found in Eastern Africa. The most complete skull belongs to a male with an estimated cranial capacity of 1,450 cm, within the range of modern brain size.
