The impact of climate change and climate variability on human populations during the last Glacial
The dispersal of modern humans into Eurasia and the extinction of Neanderthals during the last glacial period coincide with a pronounced period of climate instability. Prior to this, anatomically modern humans and Neanderthals produced very similar archaeological signatures and probably led very similar lives. By 45,000 years ago, however, modern human populations had adopted an Upper Palaeolithic culture characterized by the exchange of symbolic items of material culture within spatially extensive social networks and were dispersing across Eurasia. Several interesting questions arise from these observations, the most important of which concerns the role played by climate change in the development of modern human culture, the dispersal of modern human populations and the extinction of the Neanderthals (d'Errico and Sánchez Goñi 2003; Gamble et al. 2004; Müller et al. 2011; van Andel 2003). Our research will address these questions using the archaeological record and high-resolution climate simulations covering the last glacial period in Europe. The specific timeframe of interest begins 60,000 years ago with Marine Isotope Stage 3 (MIS 3) and finishes at the end of the Last Glacial Maximum (LGM), 19,000 years ago. Climate conditions directly and indirectly affect the spatial distribution and mobility of prehistoric populations; mobility patterns, in turn, are intrinsically linked to patterns of social organisation and the production of material culture (Delagnes and Meignen 2006; Delagnes and Rendu 2011; Kuhn 1995). Thus, climate change is a potentially significant factor to consider when studying the cultural dynamics of prehistoric people.
With few exceptions (Banks et al. 2013) archaeologists have used climate simulations at relatively coarse spatial (>100 km2) and temporal resolution to investigate the impact of climate change on prehistoric populations (Davies and Gollop 2003; Gamble et al. 2004; van Andel 2003). Climate change and climate variability have yet to be thoroughly investigated at finer spatial and temporal scales, however. The amplitude of climate change and the degree of variability required to affect social networks and stimulate dispersal are not yet established, therefore, nor do we fully understand how humans and Neanderthals may have differed in their response to environmental change at different scales. Our research programme aims to correct this situation by using high-resolution climate simulations (14 km2) which we have developed for this purpose to create detailed, dynamic spatial models of the geographic distribution of modern human and Neanderthal populations in Western Europe during the last glacial period. These models will allow us to track the responses of Neanderthal and modern human populations to environmental change at a critical period in their biological and cultural evolution (MIS3 to the LGM). We will also use these models to evaluate the relative importance of two hypothetical dispersal routes for modern humans entering Western Europe: 1) the Middle Danube and the Rhône valley corridor; 2) the Mediterranean route, which connects coastal Italy (Liguria) to France and the Iberian Peninsula. Finally, the predictive power of the spatial models we produce will be harnessed to design archaeological field surveys along the proposed dispersal routes. The results of this research programme will help fill significant gaps in our understanding of the fate of Neanderthals and the history of human colonisation of Europe as well as contributing to a better understanding of the range of reactions human societies display in the face of climate change with implications for the future.