Fig. 1

GWAS in bottlenecked European populations catch different types of disease loci than GWAS in non-bottlenecked African populations. Ancestral risk alleles are labeled red and derived risk alleles are labeled blue. Statistical power to detect associations is maximized at intermediate allele frequencies in the study population (gray shading). Filled circles indicate disease loci that are able to be caught by a GWAS, and open circles indicate disease loci that are unable to be caught by a GWAS. a Prior to divergence, allele frequencies are the same in both populations. b Non-African populations experience greater amounts of genetic drift. Diffusion of allele frequencies following divergence is indicated by red and blue shading. c European GWAS are predicted to catch derived risk alleles that have higher frequencies in Europe and ancestral risk alleles that have higher frequencies in Africa. d African GWAS are predicted to catch a relatively unbiased set of risk alleles