For this period in Europe much has been done to classify and group in sequence cultures identified by their implements. The climate was not constant; though usually cold, there were important fluctuations, probably including the sharp onset of the coldest conditions for a million years somewhere about 20,000 years ago. Such climatic variations still exercised great determinative force on the evolution of society. It was perhaps 30,000 years ago that the climate changes began which later made it possible for human beings to enter the Americas, crossing from Asia by a link either provided by ice or by land left exposed because the ice-caps contained so much of what is now sea-water and the sea-level was much lower. They moved southwards for thousands of years as they followed the game which had drawn them to the uninhabited continent. The Americas were from the start peopled by immigrants. But when the ice sheets retreated, huge transformations occurred to coasts, routes and food supplies. This was all as it had been for ages, but this time there was a crucial difference. Man was there. A new order of intelligence was available to use new and growing resources in order to cope with environmental change. The change to history, when conscious human action to control environment will increasingly be effective, is under way.
This may seem a big claim in the light of the resources early men possessed, judging by their tool kits and weaponry. Yet they already represent a huge range of capacities if we compare them with their predecessors. The basic tools of
It is tempting to see support of this in the most remarkable and mysterious evidence of all which has survived the men of the Upper Palaeolithic: their art. It is the first of its kind of whose existence we can be sure. Earlier men or even man-like creatures may have scratched patterns in the mud, daubed their bodies, moved rhythmically in dance or spread flowers in patterns, but of such things we know nothing, because, of them, if they ever happened, nothing has survived. Some creature took the trouble to accumulate little hoards of red ochre some 40,000–60,000 years ago, but the purpose of doing so is unknown. It has been suggested that two indentations on a Neanderthal gravestone are the earliest surviving art, but the first plentiful and assured evidence comes in paintings on the walls of European caves. The first were made over 30,000 years ago and their number swells dramatically until we find ourselves in the presence of a conscious art whose greatest technical and aesthetic achievements appear, without warning or forerunner, almost mature. They continue so for thousands of years until this art vanishes. Just as it has no ancestor, it leaves no descendant, though it seems to have employed many of the basic processes of the visual arts still in use today.