ipPCA-guided STRUCTURE analysis on selected individuals from the Tishkoff et.al. dataset. A) All individuals assigned to SP4, SP5, SP15 and SP16 (see Figure 5), which included all African-American individuals, were analyzed by STRUCTURE from K = 2 to K = 5. Individuals were sorted according to the ipPCA assignments. Major ethno-linguistic labels for individuals within each subpopulation are also shown (see Figure 5 for complete listing). B) Expanded view of African-American individuals from A).