Thursday, March 18, 2010

Climate Change and Human Evolution

ScienceDaily is reporting on an initiative by the National Research Council to understand how past climatic disturbances affected human evolution. The author writes:
Climate and fossil records suggest that some events in human evolution -- such as the evolution of new species or movements out of Africa -- coincided with substantial changes in African and Eurasian climate. This raises the intriguing possibility that environmental factors affected or controlled our species' evolution. By altering the landscape, past changes in climate may have exerted pressures that led to genetic selection and innovation in humans.
This is not really a new idea. From Elizabeth Vrba's turnover pulse hypothesis in the 1980s to the notion of biocultural evolution, it is clear that humans have been affected in large ways by climatic shifts. While it is quite possible that bipedalism originated in a forest environment, with the expansion of the grasslands and savannas, it took off. Neandertals adapted to a ridiculously cold environment in Europe that saw the tundra line at Vienna and glaciers completely covering Great Britain and Scandinavia. When the weather got warmer during the Würm interstadial, the modern traits began to arise, through assimilation, replacement or hybridization.

What I think is at the root of this enterprise is a major effort to research palaeoclimatology, to see if it can be used to predict what might happen in the future. The problem I see is that there are no reasonable analogues. Neandertals were using flakes and rudimentary blades to hunt and cook food. We have had toasters for a hundred years. Research into palaeoclimatology will yield clues to how we evolved, but, perhaps, not how we would currently face an impending climate crisis—especially if we don't know what that is going to be.

No comments:

Post a Comment