Australopithecus Afarensis, and Australopithecus Africanus Essay

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The phylogeny started off with Proconsul heseloni as the common ancestor to Sivapithecus indicus, Australopithecus afarensis, and Australopithecus Africanus. The reasoning for this was from the approximated age of Proconsul heseloni of 23 million years ago. This places Sivapithecus indicus roughly 15 million years after, suggesting that Sivapithecus indicus directly evolved from Proconsul heseloni.
From Proconsul heseloni, it was decided that three species evolved from it. These species included A. A. afarensis, A. africanus and Sivapithecus indicus. Sivapithecus indicus was branched off the early human evolutionary line as the characteristics from the dentation and skull characteristics differed from that of A. afarensis and A. africanus (See Fig.1 Dentation of early humans, Fig.2 Skull Characteristics of early humans).
P. Boisei was placed as a direct descendent Sivapithecus indicus and not of Proconsul heseloni. Justification for this was the data obtained through the comparison of skulls. P. Boisei has a similar brain size to body weight ratio to that of Sivapithecus indicus, indicating that whilst they were not identical, the brain to body weight ratio may have increased through evolution over millions of years. More reasoning of this placement is that the characteristics of P. Boisei were similar to the modern chimpanzee, which is known to be a descendant of Sivapithecus indicus.
As time progress on the phylogeny, Australopithecus africanus and Australopithecus…