The timing and spatiotemporal patterning of Neanderthal disappearance

Accelerator mass spectrometry radiocarbon dating is used to construct a chronology of Neanderthal disappearance, showing that Neanderthals overlapped with anatomically modern humans for between about 2,000 and 5,000 years. Gradual displacement of Neanderthals Did anatomically modern humans coexist with Neanderthals? Attempts to answer this question are complicated by the fact that conventional methods of radiocarbon dating become unreliable at just about the time in question: as sample ages approach 50,000 years little carbon-14 is left and it is difficult to obtain accurate measurements. Tom Higham and colleagues have worked to improve sample processing and accelerator-mass-spectrometry radiocarbon dating in order to construct a robust chronology based on the last appearances of the Mousterian tool culture -- considered diagnostic for the presence of Neanderthals -- from forty sites from Spain to Russia. The results indicate that Neanderthals disappeared at different times in different regions, with a significant overlap with incoming modern humans for around 2,600 to 5,400 years. Rather than a rapid model of replacement, this work suggests a complex picture in which cultural and biological interchange could have occurred between the two groups across a period of several thousand years. The timing of Neanderthal disappearance and the extent to which they overlapped with the earliest incoming anatomically modern humans (AMHs) in Eurasia are key questions in palaeoanthropology.sup.1,2. Determining the spatiotemporal relationship between the two populations is crucial if we are to understand the processes, timing and reasons leading to the disappearance of Neanderthals and the likelihood of cultural and genetic exchange. Serious technical challenges, however, have hindered reliable dating of the period, as the radiocarbon method reaches its limit at ~50,000 years ago.sup.3. Here we apply improved accelerator mass spectrometry .sup.14C techniques to construct robust chronologies from 40 key Mousterian and Neanderthal archaeological sites, ranging from Russia to Spain. Bayesian age modelling was used to generate probability distribution functions to determine the latest appearance date. We show that the Mousterian ended by 41,030-39,260 calibrated years bp (at 95.4% probability) across Europe. We also demonstrate that succeeding 'transitional' archaeological industries, one of which has been linked with Neanderthals (Châtelperronian).sup.4, end at a similar time. Our data indicate that the disappearance of Neanderthals occurred at different times in different regions. Comparing the data with results obtained from the earliest dated AMH sites in Europe, associated with the Uluzzian technocomplex.sup.5, allows us to quantify the temporal overlap between the two human groups. The results reveal a significant overlap of 2,600-5,400 years (at 95.4% probability). This has important implications for models seeking to explain the cultural, technological and biological elements involved in the replacement of Neanderthals by AMHs. A mosaic of populations in Europe during the Middle to Upper Palaeolithic transition suggests that there was ample time for the transmission of cultural and symbolic behaviours, as well as possible genetic exchanges, between the two groups.
Author(s): Tom Higham [sup.1] , Katerina Douka [sup.1] , Rachel Wood [sup.1] [sup.2] , Christopher Bronk Ramsey [sup.1] , Fiona Brock [sup.1] , Laura Basell [sup.3] , Marta Camps [sup.4] [...]