Wednesday, December 19, 2007

Human evolution is accelerating?

I take the opportunity to make brief mention here of a study from the International HapMap Project (their website here).

I've read rather different takes on their claim that human evolution is speeding up. I have in front of me one article from the New Scientist, and another from the Sydney Morning Herald (sourced from the Guardian).

They quote different authors of the same study, published in the Proceeedings of the National Academy of Sciences, whose gist is this acceleration.

The New Scientist version (which I would trust more) quotes 1800 genes (7% of the human genome) as having changed through natural selection in the past 50,000 years. Examples of changes given (variously by the reports) include resistance to colder climates and to some diseases, and lactose tolerance into adulthood - for some.

The Herald/Guardian report at least quotes some dissenting views, which tend to revolve around the notion that our manipulation of environment (including built environment and technology) have now sheltered us from the effects of natural selection.

I'm not an expert in genetics, but I remain skeptical, largely for the reason above, but also because it sounds to me (at this stage in my readings) so damn counterintuitive.

One of the authors, paleoanthropologist John Hawks, has at least one blog - possibly several - and he writes here on this study. Sounds like that's preliminary, with more to come.

I'm happy to be proven wrong. There is undoubtedly some philosophical/epistemological debate around this.

11-Aug-09 Update: I would note that recent readings suggest humans are not likely to be up for much further evolution - simply because we mould our own environment, and we are so numerous. Unless there is some global environmental disaster to cause a genetic 'bottleneck', any mutations will get lost in the mix, and will not in any case experience selection specifically for survival.

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