The Evolution of Primates

Free Response

How did archaic Homo sapiens differ from anatomically modern humans?


Archaic Homo sapiens differed from modern humans by having a thick skull and a prominent brow ridge, and lacking a prominent chin.

Why is it so difficult to determine the sequence of hominin ancestors that have led to modern Homo sapiens?


The immediate ancestors of humans were Australopithecus. All people past and present, along with the australopithecines, are hominins. We share the adaptation of being habitually bipedal. The earliest australopithecines very likely did not evolve until 5 million years ago. The primate fossil record for this crucial transitional period leading to australopithecines is still sketchy and somewhat confusing. By about 2.5 million years ago, there were at least two evolutionary lines of hominins descended from early australopithecines.