A study on a piece of jawbone from a cave in Devon, UK, has revealed that modern humans were living in northwestern Europe between 41,000 and 44,000 years ago, scientists report in the journal Nature today.
This suggests early modern humans, Homo sapiens, dispersed across Europe quicker than previously thought. Homo sapiens migrated out of Africa around 60,000 years ago and, until now, evidence of the first arrivals in Europe had been from remains dating to about 40,000 years ago.
The study also reveals more clues about our co-existence with Neanderthals and suggests there was a significant overlap in time, something that has been in dispute.
The piece of jawbone with 3 teeth from Kent's Cavern. It was uncovered in 1927 and originally dated to 35,000 years old but scientists have now carried out more accurate dating giving an even older age.
The study on a piece of maxilla, or upper jaw, with 3 teeth from Kent’s Cavern near Torquay, Devon, was led by scientists at the Natural History Museum and the University of Oxford, and is part of the Ancient Human Occupation of Britain (AHOB) project.
Another study, also published today in Nature, by an Oxford University scientist and collaborators, dates 2 early modern human teeth from Cavallo, Italy, to 43,000-45,000 years old. This makes them the earliest remains of modern humans in the whole of Europe.
Both studies confirm a much earlier dispersal of modern humans across both southern and northern Europe during the time of Neanderthal occupation.
The Kent's Cavern jawbone was uncovered in 1927 and had previously been dated to around 35,000 years old. However, doubts were raised about the reliability of this age because traces of glue, which was used to conserve the bone, were found on its surface, meaning it was probably contaminated.
The remaining uncontaminated bone fragment was too small to re-analyse so the team dated animal remains excavated from the same site, above and below where the jawbone was found. The bones from a wolf, deer, cave bear and woolly rhinoceros had been looked after at the Torquay Museum in Devon.
CT scan of Kent’s Cavern maxilla before reconstruction. It was part of the upper jawbone. © University of Hull and the Hull York Medical School/ Torquay Museum
The animal bones were radiocarbon dated and then the team carried out a statistical analysis that gave them an age for the jawbone of between 41,000 and 44,000 years old.
‘The new dating evidence we have obtained allows us for the first time to pinpoint the real age of this key specimen,’ says Professor Thomas Higham of the Oxford Radiocarbon Accelerator Unit. ‘We believe this piece of jawbone is the earliest direct evidence we have of modern humans in northwestern Europe, at a site at the very outermost limits of the initial dispersal of our species.’
Human origins expert Professor Chris Stringer of the Natural History Museum, who is co-leader of the research team and author of the new book The Origin of Our Species, comments, 'This research has been underway for the last decade, but it was only with the application of the latest investigative and dating techniques that we were able to make this breakthrough in identifying the jawbone as early modern human.'
The new date suggests modern humans may have been living in Europe at the same time Neanderthals were, and so the team needed to make sure the jawbone belonged to a modern human and not a Neanderthal.
Stringer and Tim Compton, also of the Natural History Museum, used a 3D virtual model based on a CT scan of the jawbone, created by scientists at Hull and York universities, to carry out a detailed analysis (a video clip is shown at the top of page). The scan reveals great detail without damaging the specimen and the resulting models are extremely accurate virtual replicas.
They were able to compare the internal and external shapes of the teeth with those of modern human fossils from Gough’s Cave in Somerset, UK, and Neanderthal fossils from a number of different sites.
They found early modern human characteristics in all but 3 of the 16 dental characteristics. Stringer explains, 'While the dominant characteristics are certainly modern, there are some which are ambiguous, or fall into the Neanderthal range.'
‘The Neanderthal characteristics most likely reflect inadequate sampling of modern human variation or shared primitive features between early modern humans and Neanderthals, and it will take further study and new discoveries to resolve such questions.’
The new dating evidence could solve the apparent discrepancy between the known dates of the Aurignacian period, in which artefacts and tools thought to be produced by the earliest modern humans in Europe had much older dates than their rare skeletal remains.
Aurignacian tools and ornaments were dated as early as 43,000 years ago. Previous attempts to date relevant human remains resulted in dates that reached no further than between 41,000 and 39,000 years old, indicating a significant gap.
Higham says of the new date, ‘It confirms the presence of modern humans at the time of the earliest Aurignacian culture, and tells us a great deal about the dispersal speed of our species across Europe during the last Ice Age.'