New insights on Neanderthal distribution and extinction

In order to progress the understanding of Neanderthals, where they lived and when they went extinct, researchers need accurate dates where possible. Professor of Archaeological Science and Deputy Director of the Oxford Radiocarbon Accelerator Unit Tom Higham explains how his team was able to bring new evidence to bear on these questions with refined radiocarbon dating methods.

Transcript

PROF TOM HIGHAM

The distribution of Neanderthals is interesting. This map shows the locations where we find Neanderthals living. And this is based on the presence of their fossils and also the archaeological evidence that we link to them. And so you can see that they’re concentrated mostly in Europe. They go down into the Near East – down in modern-day Israel – into Iraq, Iran. And since 2008, we now know that they also were present in the Siberian Altai, because geneticists in Leipzig analysed the DNA of a large femur from a robust individual, and the DNA suggested it was Neanderthal, so we pushed out the distribution all the way out here. Neanderthals may have been more widely distributed even than this, but this is where we’re fairly sure that they lived. They could, for example, have also lived down in Saudi Arabia and perhaps in the subcontinent, but at the moment, the evidence is hard to interpret.

One of the big questions about Neanderthals is when did they go extinct? When did they disappear is something that my team in Oxford has been really working hard at and trying to understand, and it all revolves around the reliability of dating. This illustration was taken from a Nature review article in 2006, and it shows the distribution of very late dated Neanderthals. So the ones here in the south of Spain at a series of sites, including Gorham’s Cave in Gibraltar, are generally associated as being examples of where we find Neanderthals that are less than 30,000 years of age. And this site here at Mezmaiskaya in Russia is another one where we find Neanderthals dating to – according to this illustration anyway – between 30 to 35,000.

What we decided to do was to go back to some of these sites and test them again.

This is that site in the Russian Caucasus called Mezmaiskaya, and they found there two amazing little infant Neanderthals’ complete remains. And 20 or so years ago, one of these skeletons was dated to just over 29,000 radiocarbon years BP. So we went back to the same collection of material, and we dated another Neanderthal skeleton, which was found above this so therefore it should be younger, and we got a date which was much older – around 40,000 years ago. And this to us indicates another in the long pattern of underestimated radiocarbon dates based on insufficient decontamination.

Another site in the south of Spain. This date here of a bone found near this amazing complete mandible with a date of 33,000. We redated the same bone. These are just two of the dates. We’ve done the same date about four times, and they’re always greater than ages – that means they’re beyond the radiocarbon limit, more than 48,000 years ago.

So one by one, we’ve managed to go through these late surviving supposed Neanderthals and remove them from the record. Not only that though, we’ve also gone back and we’ve done a huge amount of dating from other sites from right across Europe all the way from the west of Spain over to the Levant and to Russia. And these are the summary data of all of the results we’ve got.

So what you’re seeing here are dates of the most recent archaeological sites which contain Neanderthals. And what you can see here is that they all cluster to between 45 to 50,000 years ago. And we can calculate a more precise date for the end or the demise of Neanderthals using a statistical technique called Bayesian modelling, and basically what we get is a range between 41,000 to just over 39,000 years ago. That is our estimate of the extinction of Neanderthals in Europe, based on 40 sites and more than 200 radiocarbon dates. And this is the summary of about 7 years of work. And it was published, this paper last year in the journal Nature. And we found this result on the basis of all of this work. So that gives you a little insight into the disappearance dates of Neanderthals.

The Science Learning Hub would like to acknowledge: Professor Tom Higham, University of Oxford The Allan Wilson Centre for Molecular Ecology and Evolution B&W map of Neanderthal distribution in Europe: Neanderthals in central Asia and Siberia. Johannes Krause, Ludovic Orlando, David Serre, Bence Viola, Kay Prüfer, Michael P Richards, Jean-Jacques Hublin, Catherine Hänni, Anatoly P Derevianko and Svante Pääbo. Nature, 449, 902-904 (18 October 2007). doi:10.1038/nature06193 Model of Neanderthal man, © The Trustees of the Natural History Museum, London/Kennis & Kennis Reconstructions Eric Delson and Katerina Harvati, Palaeoanthropology: Return of the last Neanderthal. Nature, 443, 762-763 (19 October 2006) | doi:10.1038/nature05207, published online 13 September 2006 Virtual reconstruction of Neanderthal infant skeletons from Mezmaiskaya Cave, Russia, and Dederiyeh Cave, Syria. Dr Marcia Ponce de León and Professor Christoph Zollikofer Zafarraya Neanderthal mandible bone, C Barroso-Ruíz Map of redated Neanderthal sites, The timing and spatiotemporal patterning of Neanderthal disappearance. Tom Higham, Katerina Douka, Rachel Wood, Christopher Bronk Ramsey, Fiona Brock, Laura Basell, Marta Camps, Alvaro Arrizabalaga, Javier Baena, Cecillio Barroso-Ruíz, Christopher Bergman, Coralie Boitard, Paolo Boscato, Miguel Caparrós, Nicholas J Conard, Christelle Draily, Alain Froment, Bertila Galván, Paolo Gambassini, Alejandro Garcia-Moreno, Stefano Grimaldi, Paul Haesaerts, Brigitte Holt, Maria-Jose Iriarte-Chiapusso, Arthur Jelinek et al. Nature, 512, 306–309 (21 August 2014) doi:10.108/nature1 621 Neanderthal couple models courtesy of S Estressangle/E Daynes