A. afarensis

The experts think of slow transitions but their own evidence says replacements. The analysis of a nearly complete skeleton found in the Afar Valley of Ethiopia told Johanson and his colleague that A. afarensis was a true upright walker with a brain about as large as that of a chimpanzee.4 More than 10 years after this sensational... 

Fig. 12.5. This gives an even more expanded view of the last 5,000,000 years, the time of homonids. At this scale one sees distinct differences, for example, between the origin of A. afarensis and the time when it became visible (arrow points) until extinction. Notice that H. erectus origin is somewhat later but the species is well established before the extinction of A. afarensis. Again, H. neanderthalenses and H. sapiens overlap H. erectus and probably numerous other homonids yet to be discovered.

Australopithecus A genus of fossil primates that lived 4-2 million years ago, coexisting for some of this time with early forms of humans (see Homo). They walked erect and had teeth resembling those of modem humans, but the brain capacity was less than one-third that of a modern human. Various finds have been made, chiefly in East and South Africa (hence the name, which means southern ape ). The earliest belong to the species A afarensis, which includes the specimen of a female, dubbed Luc/, found at Laetoli in Tanzania. Australopithecus and related genera are known as australopithe-cines. 

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