Message #208106

[Kara Sundstrom]

Clottes, however, thinks they could be on to something. "Language and abstract thought were probably practised long before 35,000 years ago, since 'modern humans' are some 200,000 years old. We shouldn't be surprised by the sophistication of these people's thinking: they were our great-great-grandparents after all," he says.

But if people really did have a symbolic culture this far back, why don't we find more evidence pre-dating 40,000 years ago? "Perhaps the earlier symbols tended to be carved into perishable things such as wood and skins, which have now disintegrated," says von Petzinger. And even if they did paint in caves many of the rock surfaces will have eroded away by now.