Geographical coverage of hierarchical genetic subgroups detected in East Asia. (a) The initial division at K = 2 introduced a north-south partition. (b) Subsequent analysis allowed the Yakut to be nearly completely isolated. (c) Division in the southern cluster (S5A-2) produced four distinct clusters, one with a southern orientation (S5C-1), a westerly group (S5C-2), a completely isolated Lahu cluster (S5C-3) and a strongly anchored Japanese cluster (S5C-4). (d-f) Further analysis allowed the separation of a distinctly Japanese group (S5F-2) and mixed membership clusters in the remainder of the groupings.