Anatomy, Behavior, and Modern Human Origins
Richard G. Klein~ 1995
The fossil record suggests that modern human morphology evolved in Africa between 150,000 and 50,000 years ago, when the sole inhabitants of Eurasia were the Neanderthals and other equally nonmodern people. However, the earliest modern or near-modern Africans were behaviorally (archaeologically) indistinguishable from their nonmodern, Eurasian contemporaries, and it was only around 50,000-40,000 years ago that a major behavioral difference developed. Archaeological indications of this difference include the oldest indisputable ornaments (or art broadly understood); the oldest evidence for routine use of bone, •ory, and shell to produce formal (standardized) artifacts; grea@ accelerated variation in stone artifact assemblages through time and space; and hunting-gathering innovations that promoted significantly larger populations. As a complex, the novel traits imply fully modern cognitive and communicative abilities, or more succinctly, the fully modern capacity for Culture. The competitive advantage of this capacity is obvious, and preliminary dates suggest that it appeared in Africa about 50,000 years ago and then successively in western Asia, eastern Europe, and western Europe, in keeping with an African origin. Arguably, the development of modern behavior depended on a neural change broadly like those that accompanied yet earlier archaeologically detectable behavioral advances. This explanation is problematic, however, because the putative change was in brain organization, not size, and fossil skulls provide little or no secure evidence for brain structure. Other potential objections to a neural advance in Africa 50,000–40,000 years ago or to the wider “Out-of-Africa” hypothesis, include archaeological evidence (1) that some Neanderthals were actually capable of fully modern behavior and (2) that some Africans were behaviorally modem more than 90,000 yeats ago.
My purpose is to place the origin of modem humans in the broad sweep of human evolution and to show that an understanding of modern human origins depends as much on archaeology as on the fossil record. My basic argument flows from the familiar, but controversial observation that a bundle of interrelated behavioral novelties appeared abruptly be- tween 50,000 and 40,000 years ago (Table I). Preliminary indications are that key elements of this bundle originated in Africa, in keeping with fossil evidence that the first physically modem or near-modern humans evolved there between 150,000 and 50,000 years ago. During this same interval the sole inhabitants of Eurasia were the Neanderthals and other, equally non- modem (“archaic”) people. In my view, the novel behavioral complex sig- nals the emergence of fully modem cognitive and communicative abilities, or more succinctly, the emergence of the modem capacity for Culture. The development of this capacity in turn explains how modem humans were able to expand from Africa about 50,000 years ago to supplant the Neanderthals and other archaic Eurasians whose cultural potential was more limited.