The transition from the historical period known as the Middle Paleolithic to the Upper Paleolithic around 40 to 35 thousand years ago (kya) represents one of the major developments in the prehistory of humankind. The basic features of this transition include more versatile stone implements and the use of antler, bone, and ivory for tools, figurative art, music, and personal decoration. So striking were the strides in human achievement during this period that it is sometimes referred to as the Upper Paleolithic Revolution.

Until recently it had been argued that the Upper Paleolithic Revolution was an archaeological phenomenon found only in Eurasia. The apparent lack of equivalent evidence in other regions suggested that a fundamental change had occurred in human intellectual development around 40 kya in Europe. The recent discovery in the Blombos Cave in South Africa of a block of decorated ochre and then sets of shell beads, dated to around 77 kya, opened up the debate. This supports other evidence of more versatile stone implements and bone tools found in Africa from the same period. Now the Upper Paleolithic Revolution is being seen as simply the most visible example of the evolving process of modern human behavior that had been developing over a much longer timescale.

This raises two further questions. First, what was happening to the human cognitive process during the 40,000 years or so between the creations in the Blombos Cave and the flourishing of human creativity in Europe around 35 kya, and second, was climate change a component Climate change is associated with the sudden occurrence of creative activity in Europe at the beginning of the Upper Paleolithic.

The question of whether the sudden transition seen in Europe was built on earlier developments in Africa has been addressed at length by anthropologists Sally McBrearty and Alison Brooks. They argue that the whole issue of the Upper Paleolithic Revolution stems from a profound Eurocentric bias and a failure to appreciate the depth and breadth of the African archaeological record. In fact, many of the components of this revolution are found earlier in the African Middle Paleolithic tens of thousands of years before they appeared in Europe. These features include blade and microlithic technology, bone tools, increased geographic range, specialized hunting, exploitation of aquatic resources, long-distance exchange networks, systematic processing and use of pigment, and art and decoration. These items do not occur suddenly together as predicted by the revolutionary model, but at sites that are widely separated in space and time. This suggests a gradual assembling of the package of modern human behaviors in Africa and its later export to other regions of the Old World.

The extraordinary range of rock art in Australia adds great weight to the idea that artistic creativity was part and parcel of the intellectual capacity of modern humans that migrated out of Africa around 70 kya. The fact that these people almost certainly arrived in Australia before 60 kya and were, in any case, completely isolated from any evolutionary events that may have occurred in Europe around 40 kya makes this argument compelling.

The consequence of this analysis is that the question of the sudden emergence of creative activity that appears to constitute the Upper Paleolithic Revolution falls to the ground. The obvious explanation is that the gap between African developments and the subsequent better-known European events is a matter of the limitations of the archaeological record. This does not altogether cover the question of why there was the sudden flowering of creativity at the beginning of the Upper Paleolithic in Europe. It may be that earlier creative efforts have either been lost in or have yet to emerge from the mists of time. Recent finds of decorative pierced shells dating from 43 kya or even earlier in caves in parts of western Asia near Europe may be examples of a process extending the evidence back in time. The creative flowering may also be a result of the climatic conditions at the time that governed the movement of modern humans into Europe. Following a period of extreme cold around 39 kya, a period of warming around 35 kya rendered the region more hospitable. As the ancestors of today's Europeans moved into a largely depopulated region, their presence in the archaeological record appeared revolutionary.