ies in the large size of their chewing teeth, jaws, and jaw muscles. The robust australopithecines became extinct about 1.5 million years ago. Although scientists do not agree, many believe that after the evolutionary split that led to robust australopithecines, A. africanus evolved into the genus Homo. This was a species called Homo habilis, or "handy man." Appearing about 2.5 million years ago, the new hominid probably didn't look terribly different from its predecessors, but it had a somewhat larger brain. And, perhaps as a result of some mental connection other hominids were unable to make, Homo habilis figured out for the first time how to make tools. Earlier species had used tools like bits of bone for digging, or sticks for fishing termites out of their mounds (something modern chimps still do). But Homo habilis deliberately hammered on rocks to crack and flake them into useful shapes. The tools were probably not used for hunting, as scientists once thought. Homo habilis, on average, was less than 5 ft. tall and weighed less than 100 lbs., and it could hardly have competed with the lions and leopards that stalked the African landscape. The hominids were probably scavengers instead, supplementing a mostly vegetarian diet with meat left over from predators' kills. Even other scavengers like hyenas, jackals and such were stronger and tougher than early humans. But Homo habilis presumably had the intelligence to anticipate the habits of predators and scavengers, and probably used tools to butcher leftovers quickly and get back to safety. Their adaptations to the rigors of prehistoric African life enabled members of the Homo habilis species to survive for 500,000 years or more, and at least one group of them apparently evolved, around 2 million years ago. Around this time, East African mammals adapted to drier more open grassland conditions. It was about this time that the new form of human emerged in Africa, a hominid with a much lar...
