Arnold Kling

Faster Human Evolution

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Tyler Cowen talks about a new scientific paper. He quotes from the UK Telegraph.


Naturally, our friends at Gene Expressions are on top of this one. Razib writes,

One can think of "per locus error rate" [p] as basically mutation rate. [N is the size of the population.] The paper suggests that Np = 1 is a major threshold , below this point stochastic effects are powerful and the ambient rate of mutation is a major parameter shaping adaptive evolution (not neutral evolution, which is not dependent on population size). When Np > 1 stochastic effects are less salient and selection is powerful enough to swamp random deviation so that it can drive beneficial mutations to fixation.


Another GNXP blogger, p-ter , writes skeptically,

is the statistical power to detect alleles of different ages identical? If the test has low power to detect old sweeps and good power to detect recent ones, there you go-- an artefactual acceleration. There is little discussion of these parameters in the original paper and less here. Don't get me wrong-- the areas of the genome they identify as selected are almost certainly enriched for true selective events, but how enriched? These questions are perhaps less important in a first-pass scan for selection, but if you're going to make generalizations about selected sites, they're essential. The claim in the paper that "demographic causes of extensive LD can be discriminated easily from those caused by adaptive selection" is not demonstrated (and is false)

I tried to explain the concept of statistical power to my high school students yesterday, and near the end of class they asked why it was important. I hope I can use this example as an answer, without having to explain (which in turn would require that I understand) the biology .

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COMMENTS (3 to date)
razib writes:

"some economists" = alex tabarrok and his cronies btw. credit where it's due. bryan was out of town.

Douglass Holmes writes:

To properly understand evolution requires an understanding of a lot of math. I would prefer that we bypass the entire intelligent design/evolution controversy in middle school and high school and just focus on the math. What I found in college, studying under a biologist who taught a lot of math, is that the mathematical story is a lot more convincing than the more popular explanations of evolution.
It probably applies to economics as well.

razib writes:

doug, most high school students are scared of math. so are most college students. so are most biology graduates!

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