ABSTRACT
Whatever the relationship of the australopithecines to ourselves, it is with the appearance of the earliest members of the genus Homo, to which we belong, that human evolution took a major leap forward. Important biological changes occurred and they were accompanied by the first indications of the human learned behaviour that anthropologists call culture. The strongest evidence for this new behaviour consists of the stone tools that were now made, probably for the first time. They demonstrate the existence of both greater manual dexterity and substantial mental development, to which their manufacture must also have contributed. Their possession enabled their makers to adapt to a greater range of environments and, almost certainly, to increase the meat content of their diet. Stone tools could also have contributed to a more efficient exploitation of plant foods and made it possible to shape wood and use animal skins. The earliest of such tools were simple and persisted from about 2.6-2.5 million years ago to about 1.7-1.6 million years ago. However, more sophisticated forms were subsequently developed and were made until about 250,000 years ago, by which time further evolutionary changes had occurred amongst their makers. Furthermore, by sometime before 1 million years ago early humans had not only spread into most African environments but had also expanded beyond the continent. Crucial to that achievement was the interaction of culture and evolution that characterized this long period.
