Archaeologists have determined that cave art on the Indonesian island of Sulawesi is just as old, if not older, than similar but much more widely known examples in Spain and France. A hand stencil was laid down there at least 39,900 years ago, they report, and a drawing of a piglike animal was sketched at least 35,700 years ago.
The researchers established the minimum age of the designs by dating mineral deposits that have formed on top of them. The deposits contain trace amounts of uranium, which decays at a steady rate to thorium, so their age can be calculated from the ratio of the two elements.
The discovery raises the question of whether human artistic expression was pioneered independently in Western Europe and Southeast Asia, or had evolved in humans before they left Africa. “We really can’t say either way, but my gut feeling is that rock art developed in Africa before our ancestors spread out of that continent,” says Adam Brumm, an archaeologist at Griffith University in Australia. “Therefore, we would expect to find rock art of a similar age in many other parts of the world.”
