Pan-continental group ancestry of African-descended Americans.

(a) mitochondrial DNA, (b) Y-chromosome (reflecting maternal and paternal admixture, respectively), (c) Ancestry Informative Markers (AIMs, reflecting the autosomal genome), showing the relative ratio of the three world populations that significantly contribute to the admixed populations of the United States (represented here as the entire US or by our sample from Philadelphia), the Caribbean Islands, and Brazil. The diverse socio-cultural histories of South and North America are reflected in sex-specific admixture and in overall admixture levels that differ between North and South America. The autosomal genome admixture proportions (c) approximately reflect the combination of the maternal and paternal contributions (a and b). AIMs-based estimates for Senegalese and Nigerian samples (far right) were added for comparison of African ancestral vs. American admixed populations. (Note: * designates samples typed and analyzed by the authors, while # designates previously published estimates. The remaining sample sets were collected from the literature as raw sequence and/or haplotype data and analyzed by the authors.)