Doubt cast on age of oldest human art

Doubt cast on age of oldest human art
11:00 18 April 03
Jenny Hogan - newscience.com

If the rock art in the Chauvet cave is 30,000 years old, it is the most ancient example of human art in existence and the implications for the evolution of culture are immense. This date is accepted and celebrated by archaeologists. But could it be wrong?

"I would be astounded if this date proves to be correct," leading archaeologist Paul Bahn says now. "It flies in the face of all we know about ice-age art." He has reignited the debate about the age of the paintings at Chauvet by questioning the science that says they are so old. The controversy is currently dividing the archaeology community.

The Chauvet cave was discovered in a valley in southern France in 1994. Its walls are a spectacular gallery of prehistoric art and the depictions of wild animals - rhino, lions and bison among others - are so sophisticated that specialists in ice-age art first assumed they must be relatively recent. Certain features, such as animals shown face on, also suggested that the cave paintings were about 15,000 years old.

But a few months later, tiny samples of black charcoal were scraped from some of the pictures and sent away for radiocarbon dating. The date that came back from the Laboratory of Climate and Environmental Science (LSCE) in Gif-sur-Yvette, France, shocked everyone. It suggested that the paintings dated to the very beginning of the Upper Paleolithic era, around 30,000 years ago (New Scientist print edition, 13 July 1996).




People are generally wary of stylistic dating, explains Paul Pettitt, an archaeologist at the University of Oxford. So once the more "scientific" radiocarbon results were available, most researchers dismissed the more recent date suggested by the paintings themselves.

Instead the carbon data was used to support the revolutionary theory that sophisticated art developed extremely rapidly once modern humans arrived in Europe, and archaeologists who thought culture evolved over millennia were sidelined.

There is good reason to doubt chronologies based purely on style, admits Chris Witcombe, an art historian at Sweet Briar College in Virginia. He explains the difficulty with an analogy: "Imagine you are living in the distant future and only two objects survive from a lost and forgotten past: a painting by Picasso and a painting by Michelangelo. Which is the earlier work and which the later?"

But archaeologists must also be wary of radiocarbon dates, argue Pettitt and Bahn in a paper that appeared in Antiquity last month. Bahn's suspicions were aroused when he translated the latest coffee-table book on the Chauvet cave into English. Around 30 radiocarbon ages are presented in this book, but the measurements were all made at the same French laboratory. Using results from only one team, however skilled, just is not scientific, says Bahn.

Worse, the same laboratory is currently embroiled in an argument over the age of the artwork in another cave, Candamo in Spain. They dated black dots on its walls to 30,000 years ago, but Geochron Laboratories in Cambridge, Massachusetts, estimated the age of a second sample to be just half that.

The point is that carbon dating rock art is difficult. Because the samples tend to be incredibly tiny, it is difficult to measure the number of carbon-14 atoms relative to other carbon isotopes - the key ratio for pinning down the age.

"Everybody agrees there are problems," says Marvin Rowe, who heads a radiocarbon-dating lab at Texas A&M University in College Station. Contamination from groundwater or rock scrapings may further confuse the results.

Jean Clottes, the archaeologist at the French Ministry of Culture who led the team exploring the cave, stands by his Chauvet results. But he has agreed to send Rowe a sample of charcoal from the cave floor, so that they can compare their results. This is crucial, says Pettitt. "We are not saying the dates are necessarily incorrect, but they need to be checked."