Limb lengths in Australopithecus and the origin of the genus Homo

The recent discovery of fossil limbs of Australopithecus africanus,(1) incl uding a partial skeleton, makes it possible to compare body proportions of this 3-2.3-million-year-old species with those of A. afarensis (3.9-3 Myr), Homo habilis (2-1.6 Myr), and H. ergaster/erectus (1.9-0.4 Myr). Australop ithecus africanus is more similar to H. habilis in having larger forelimbs and smaller hindlimbs than expected from proportions seen in later Home. Cu riously the earlier and craniodentally more primitive A. afarensis is more similar to later Home in fore-to-hindlimb proportions. This implies that li mb proportions changed back and forth in the hominid lineage or our present view of hominid relationships is too simplified.