It is known that Northern Europeans tend to be somewhat taller than Southern Europeans. This seems intuitively obvious if you spend a bit of time around representative populations. Growing up in the Pacific Northwest I’ve always been on the short side at 5 feet 8 inches, but when I was in Italy for 3 weeks one year back (between Milan and Rome, with disproportionate time spent in the Piedmont) I didn’t feel as small (I recall feeling similarly when I was in Cajun country in the early 2000s). Steve Hsu alerts me to the fact that Luke Jostins is back blogging at Genetic Inference, reporting from the Biology of Genomes meeting. Apparently Michael Turchin has found that:
1) Alleles known to be associated with greater height are found at higher frequencies in Northern Europeans
2) Alleles known to be associated with greater height also exhibit signatures of natural selection
He used the GIANT consortium data set. How big is it? 129 thousand individuals! Luke adds:
This is a textbook example of how an evolutionary study should be done; you show a phenotypic difference exists, that it is heritable, and that it is under selection. This opens the question as to why height has been selected in Northern Europe (or shortness in Southern Europe). Could the same data be used to test specific hypotheses there?
One thing we do know is that there isn’t much difference in heights between black Americans and white Americans, who are predominantly Northern European in ancestry. I wonder if perhaps the smaller sizes of Southern Europeans is due to the fact that these populations have lived for a longer period under a high density agricultural regime than either Northern Europeans or Africans (northern Sweden still was dominated by hunter-gatherers until ~5,000 years B.P.). My working hypothesis that for various reasons stable agricultural societies may reduce lifetime mortality rates but maintain higher levels of morbidity, making large body sizes less feasible. But that’s just speculation. At last European is a good testing ground for these sorts of explorations, as obviously obligate nutritional differences aren’t much of an issue anymore on that continent.