Opposite selection pressures on stature and intelligence across human populations
Open Behavioral Genetics , May 12, 2014, ISSN: 2446-3876
Principal component analysis was used to detect signals of recent polygenic selection for higher stature. This selection was stronger among sub-Saharan Africans and weaker among East Asians. The principal component significantly correlates with mean male height in 9 populations. ANOVA shows that the frequencies of 46 height-increasing alleles differ significantly across three continental races (Europeans, sub-Saharan Africans, East Asians). We can therefore reject the null hypothesis that random drift accounts for these differences. GWAS hits from different population samples have similar loadings on the principal component, implying that the same alleles have similar phenotypic effects across human populations. These height-increasing alleles are distributed among the three geographic groups in a way that inversely mirrors what we see for intelligence-enhancing alleles. This pattern might be explained by Allen’s rule and the cognitive demands imposed by cold climates.