Median-joining network of FUT2 haplotypes in seven continental regions. America (gray), Central-South Asia (orange), East Asia (blue), Europe (green), Middle East and North Africa (red), Oceania (purple), and Sub-Saharan Africa (yellow). Circles correspond to haplotypes and their areas are proportional to the frequency of the haplotype. Haplotype number is shown next to circles. Inactivating mutations have been indicated by an arrow. The insert shows the same median-joining network of FUT2 haplotypes according to phenotypes: The topology is the same as in the main figure; here, colors indicate the haplotypes carrying different secretor/nonsecretor variants; se³⁰² (blue), se³⁸⁵ (gray), se⁴²⁸ (black), se⁵⁷¹ (red), and Se (yellow). The chimpanzee sequence has been included as an ancestral haplotype in both figures.