Neighbor-joining population trees for European, Jewish, and Middle Eastern populations. (a) Neighbor-joining tree based on the allele-sharing genetic distance. (b) Neighbor-joining tree based on the chord genetic distance. (c) Neighbor-joining tree based on Nei's standard genetic distance. External branches were colored to indicate the groups to which populations belong (blue - European; red - Jewish; green - Middle Eastern). Sequentially, internal branches were then colored if all colored branches to which they connected had the same color. The two remaining branches in black separate the European, Jewish, and Middle Eastern groups. The number on an edge represents the fraction of bootstrap replicates supporting that edge, among 10,000.