Figure 4.

The putatively yellow Amboseli baboon HAP exhibits a signature of historic admixture. (A) F_st levels between HAP and the SWY yellow baboon (yellow line) are low in regions inferred as homozygous yellow but high in regions of the genome inferred as homozygous anubis; the pattern is reversed for F_st comparisons between HAP and the SWA anubis baboon (green line). Genetic diversity in HAP is highest in regions of mixed ancestry (dashed gray line). (B–D) Principal components projections of genotype data on scaffolds where HAP is estimated to have homozygous yellow ancestry group him with other yellow baboons (B), but genotype data from scaffolds where HAP has heterozygous or homozygous anubis ancestry group him with hybrids (C) and anubis baboons (D), respectively. Colors depict a priori ancestry assignments based on population of origin or, for Amboseli, pedigree, life history, and morphological scores (see Methods and Table S2); shapes show population of origin. Note that –PC1 and –PC2 are plotted on the x and y-axes of (B) to maintain visual consistency with (C,D).