New radiocarbon dating suggests that Neanderthals may not have lived alongside Homo sapiens in southern Europe as thought - let alone interbred with us.
Scientists have re-dated bones from two sites in southern Spain and say the results show that they're much older than previously thought. While Homo sapiens is believed to have arrived in the region around 40,000 years ago, with the Neanderthals surviving until ten thousand years later, the new dates imply that the Neanderthals could in fact have been long gone by then.
"It is improbable that the last Neanderthals of central and southern Iberia would have persisted until such a late date, approximately 30,000 years ago, as we thought before the new dates appeared," says Jesús F. Jordá of the Spanish National Distance Education University (UNED).
The team says its radiocarbon dating method improves on standard methods by including an ultrafiltration protocol that aims to purify the collagen of the bone samples from contaminants. And, they say, the results show that Neanderthal occupation of the sites didn't last until as late as previously thought; instead it should be placed approximately 45,000 years ago.
"The problem with radiocarbon dating alone is that it does not provide reliable dates older than 50,000 years," says Jordá. "Prehistory books would need revision."
Evidence for interbreeding between Homo sapiens and Neanderthals has come in the form of Neanderthal DNA, which cal still be found in many people today. An alternative explanation for its presence would be that the two species had a common ancestor, probably living in north Africa.