Not until the late 19th century did humans learn of the extraordinary art produced by their Ice Age ancestors, the Cro-Magnon people of Western Europe. These early artists decorated walls of caves with delicate, dramatic animal paintings.
The multicolored cascades of prey and predator animals -- bison, deer, bears, cattle, mammoths, and reindeer -- are interspersed with geometric symbols and, in some places, female images probably referring to fertility. Some of the animals have been overdrawn several times and pierced with spears in what were likely some kind of ritual act.
The oldest representational cave painting dates from about 30,000 years ago. Most date from 20,000 years ago or less, in what's called the Upper Paleolithic era. Rocks were ground up to make pigments -- black and ochre were the main ones -- which were then sometimes applied to outlines of figures first engraved into the stone and at others painted directly onto the cave wall.
They were made at a time when Western Europe was dominated not by forest, but by fertile steppes that were home to an abundance of animals that the Cro-Magnons hunted, brought home, divided up, cooked, and ate. It was dangerous work, judging by a scene painted in the renowned Lascaux cave of a man being killed by a bison. Other tableaux are hard to interpret without knowing what cultural beliefs and aspirations these Stone Age artists were representing.
Because the paintings are often found deep inside caves in spots difficult to get to, it's likely that they were rarely visited and therefore of special importance. One hypothesis is that the art is reflects "sympathetic magic," a ritual aimed at bringing good luck to the hunters.
The true significance of these magnificent cave paintings at Lascaux and Chauvet in France and at Altamira in Spain remains elusive. But scientists conclude that this art, some of it brilliant even by today's standards, reflects the development of "symbolic life," an important turning point in hominid evolution that has sometimes been dubbed "the mind's big bang." The evidence for this creative spark that blossomed among our ancestors first appears in the European fossil and archeological record around 50,000 years ago. But some researchers argue that its traces can be seen in African sites that date back to 100,000 years ago or even earlier, and that as more fieldwork is done on African sites of this age, a more gradual emergence of symbolic life may be revealed.