A likely ancestor of the australopithecines is the "Ardipithecus" genus, which lived in East Africa. The genus "Homo" (humans), appears about 2.4 million years ago with "Homo habilis". Australos moved into mixed savannah/woodland habitats as the climate cooled in the later Miocene. This explains their adaptations to walking or walking plus climbing. It also explains the changes to their diet and teeth, though not in detail. The great increase in brain size of modern man began with the genus "Homo": it did not start with the australos.