Redating Neanderthals in Europe
When did Neanderthals occupy Europe, and did they overlap significantly with modern humans? This question has vexed paleontologists for decades. partly because dating methods have not been accurate enough.
The primary dating method is for dating modern human and Neanderthal sites at the crucial time, 30-50,000 years ago, is carbon 14 dating or organic remains (like charcoal from fires). This dating method, however, is accurate only to about 50,000 years, and as it gets beyond 30,000 years it becomes less accurate because little carbon isotope remains and contamination begins to have a proportionally larger effect.
Tom Higham, an archaeologist at the University of Oxford, UK, and his team, however, have developed a refined method that is accurate to 55,000 years. First they treat bone remains to remove contaminants then use a particle accelerator to detect the minute amounts of remaining carbon isotopes.
They have just published in Nature a reanalysis of 196 remains from various European sites. They found that modern humans were in southern Italy as early as 45,000 years ago. At that time Neanderthals still dominated Europe. Over the next 5 thousand years Neanderthal populations decreased, finally disappearing between 39,000-41,000 years ago.
This leaves about 5,000 years of overlap – more than enough time for exchange of culture and DNA. Modern humans, for example brought with them a more sophisticated tool kit, as well as jewelry, bone needles, and dyes. Neanderthals started showing some of the same innovations around the same time, leading scientists to speculated that they learned their new skills from modern humans.
There are still holdouts, however. Clive Finlayson is a scientists who has dated Neanderthal remains in Spain to as late as 28,000 years ago. He argues that Higham’s technique does not work as well at warmer sites, like in Spain, and there may yet be later Neanderthal sites that were not included in the study or remain undiscovered.
There clearly remains much to be discovered, but the new technique and analysis does refine our understanding of the complex history of Neanderthals and modern humans. It does not, however, answer the question of why Neanderthals became extinct while our ancestors survived and thrived.