The first humans:Modern humans belong to the mammalian order of primates, which originated about 55 million years ago; primates included the only extant hominid species. The earliest hominid was Ardipithecus (“ground ape”) and Australopithecus (“southern ape”), both small-brained intermediates between apes and humans that were capable of standing and walking upright. Homo habilis, the earliest member of the genus Homo, appeared at least 2 million years ago. This larger-brained “handy man” began making tools for hunting. Homo ergaster first appeared in Africa about 1.8 million years ago and spread into Asia about 800,000 years later. Smaller-toothed than Homo habilis, H. ergaster—followed by Homo erectus—developed fire as a tool, which enabled it to cook food. Neanderthals, a near relative of modern humans, originated about 200,000 years ago, and Homo sapiens (modern humans) appeared in Africa about 100,000 years later. The two coexisted for thousands of years, but by 30,000 years ago, Homo sapiens had become dominant and the Neanderthals had died out. Classification of Homo sapiens in relation to its ancestors is enormously problematic: modern humans must be classified not only by bone structure, but also by specific
behavior—the ability to plan future action; to follow traditions; and to use symbolic communication, including complex language and the ability to use and recognize symbols.
