Climate change or competition? What factors might have caused the extinction of the Neanderthals? Perspectives from Finlayson and Mellars & French

Finlayson (2008: 2246) argues against the extinction of Homo neanderthalensis being caused by competition from Homo sapiens. He states that evidence for this view is non-existent and is therefore not a valid theory. Instead, Finlayson posits that it was rapid climate change that fragmented resources and habitats of Neanderthal populations that led to their extinction. Giving scores to 23 potential Neanderthal sites for their suitability, Finlayson (2008: 2247-2248) found that there was a high statistical significance between his given high scores and the last occupied places by the Neanderthals i.e. Neanderthals remained in high suitability areas longer than other areas. He (Finlayson 2008: 2249) also found that coastal strongholds allowed Neanderthals to survive for longer than those more inland. This may be because “coastal areas are prime ecotones that often combine marine with terrestrial and wetland resources”, allowing individuals to maintain small homeranges, with coastal shelves permitting links to other populations (Ibid: 2251). Finally, Finlayson’s (2008: 2249) climate hypothesis shows that populations fragmented in an east-west pattern, with some exceptions of western extinctions before some eastern.

While Finlayson (2008) argues so avidly against the competition hypothesis, Mellars & French (2011: 623) postulate that Neanderthal populations were replaced by H. sapiens across Europe between 45-35 thousand years ago (kya). They base this on age ranges of three successive techno complexes; the Mousterian-of-Acheulean (44-55 kya), the Châtelperronian (40.25-44.4 kya) and the Aurignacian (35-40.25 kya) industries; meat-weight densities and occupation areas. This in turn would show; total numbers of occupied sites, overall intensity of sites and “…overall spatial extent of the archaeological occupation levels” (Ibid: 625). The research shows that over the Neanderthal-to-modern-human transition, there is an increase in human population numbers and densities (Ibid: 626). Mellars & French (2011: 627) argue that their data is consistent with other research such as DNA data and human and cave-bear occupation sites that show changing population numbers and densities between Neanderthals and humans. They suggest that their data could indicate competition between the two hominin groups. They also state that “a range of climatic and associated environmental factors could have played a further, critical role in this demographic replacement and extinction process – above all, perhaps the impact of the sudden climatic cooling associated with Heinrich event 4…”(Ibid). Although Finlayson (2008) does give a good case for climate change and the reason why coastal areas were the last strongholds, he does not explain H. sapiens role in this historical period. Surely if humans were also in the area where Neanderthal populations were, and there were drastic changes in climate to allow for Neanderthals to die out, then humans would also be affected? Humans would therefore potentially be in competition with species that occupied similar niches. Even if humans were not directly killing Neanderthals, the need for food, shelter etc in harsher climates would lead to competition. Hence, environments with more resources, such as coastal areas, would have less competition. It would be interesting to know if population density fell within the H. sapiens groups during this time also, even though they clearly had higher densities than Neanderthals. 

 

[NOTE: What is Heinrich event 4? Heinrich event 4 was an abrupt cooling event that happened between 39-40 kya (Lopez-Garcia et al. 2013: 1053). Click here to read more on Heinrich events]

Bibliography

-  Finlayson, C. (2008). On the importance of coastal areas in the survival of Neanderthal populations during the Late Pleistocene. Quaternary Science Reviews 27 (23)

- Lopez-Garcia, J. M., Blain, H. A., Bennasar, M., Sanz, M., Daura, J. (2013). Heinrich event 4 characterised by terrestrial proxies in Southwestern Europe. Climate of the Past 9

-  Mellars, P. & French, J. (2011). Tenfold Population Increase in Western Europe at the Neanderthal-to-Modern Human Transition. Science 333 (6042)