We are creatures of cold.
The changes that make the history of Homo sapiens distinctive began with a period of unprecedented cultural divergence during a spell of low temperatures (an ‘Ice Age' in conventional parlance), about a hundred thousand years ago, or a little more.
By the time global warming resumed, Homo sapiens had transformed from a small group in East Africa to a globally dispersed, relatively numerous species, living, by comparison with fellow-primates, in large communities, typically hundreds strong and sometimes larger, inhabiting environments more numerous and more diverse than those of any other known creature (apart from the bacteria we carry around in our bodies).By comparison with other surviving great apes, all of whom occupy a relatively narrow ecological range and rarely migrate beyond contiguous zones, the reach of human dispersal seems astonishing. As they multiplied in numbers and embraced a widening variety of environmental challenges, groups of Homo sapiens lost touch with each other. A long history of mutual differentiation began, which is still going on in some respects, and which has equipped this single species with an incomparably bigger range of lifeways, and a faster (and, it seems, for still poorly understood reasons, generally accelerating) rate of cultural change than any other cultural animal.
This chapter represents an attempt at three objectives: first, to document the most conspicuous and widespread of the changes that occurred during the Ice Age, and others (equally spectacular in their way) that accompanied them and followed them during the next 10,000 years or so, when climate underwent considerable fluctuations and periodically reverted to prolonged cold spells; secondly, to relate the cultural changes to environmental conditions, as far as evidence permits; and finally to broach, at least, the problem of how far environment explains (or, in language some people prefer, ‘determines') culture.