So Easy a Cave Man Can Do It

In a damp Spanish cave, Alistair Pike applies a small grinder to the world's oldest known paintings.

Every few minutes, the dentist-drill sound stops and Pike, an archaeologist from the University of Southampton, UK, stands aside so that a party of tourists can admire the simple artwork — hazy red disks, stenciled handprints, the outlines of bison — daubed on the cave wall tens of thousands of years ago. He hopes that the visitors won't notice the small scuff marks he has left.

In fact, Pike's grinder — and the scalpel that he wields to scrape off tiny samples — is doing no harm to the actual paintings, and he is working with the full approval of the Spanish authorities. Pike is after the crust of calcite that has built up over the millennia from groundwater dripping down the wall. The white flecks that he dislodges hold a smattering of uranium atoms, whose decay acts as a radioactive clock. A clock that has been ticking ever since the calcite formed on top of the art.

 

The results of an earlier round of sampling in El Castillo cave, published last June, showed that the oldest of the paintings, a simple red spot, dates to at least 40,800 years ago, roughly when the first modern humans reached western Europe. Pike and his colleagues think that when they analyze the latest samples, the paintings may turn out to be older still, perhaps by thousands of years — too old to have been made by modern humans. If so, the artists must have been Neanderthals, the brawny, archaic people who were already living in Europe.  Read more:

The Neanderthals are an extinct species or subspecies of the genus Homo which is closely related to modern humans. They are known from fossils, dating from the Pleistocene period, which have been found in Europe and parts of western and central Asia. The species is named after Neandertal ("Neander's Valley"), the location in Germany where it was first discovered.

Neanderthals...

Neanderthals are classified either as a subspecies of Homo sapiens (Homo sapiens neanderthalensis) or as a separate species of the same genus (Homo neanderthalensis). The first humans with proto-Neanderthal traits are believed to have existed in Europe as early as 600,000–350,000 years ago.