August 13, 2005

Ancestry of African Americans

A comprehensive new study of African American mtDNA in comparison to African mtDNA indicates that African Americans are primarily descended from West, West-Central, and South-Western Africa, with negligible contributions from Northern, East, Southern, and Southeastern Africa. As common sense would suggest, African Americans are descended from the primary Negroid area of Africa:
Africa is the most genetically diverse continent. A fine subdivision of African mtDNA lineages provides a powerful source of phylogeographic information: major regions of the continent display markedly different frequencies of the continent-specific mtDNA clades, or haplogroups (fig. 1a). However, the first point to make from this enhanced data set is the obvious similarity of the haplogroup frequency profiles of West Africa, west-central Africa, and southwestern Africa in comparison with the other major regions of the continent.

Am. J. Hum. Genet (Early View)

Charting the Ancestry of African Americans

Antonio Salas et al.

The Atlantic slave trade promoted by West European empires (15th–19th centuries) forcibly moved at least 11 million people from Africa, including about one-third from west-central Africa, to European and American destinations. The mitochondrial DNA (mtDNA) genome has retained an imprint of this process, but previous analyses lacked west-central African data. Here, we make use of an African database of 4,860 mtDNAs, which include 948 mtDNA sequences from west-central Africa and a further 154 from the southwest, and compare these for the first time with a publicly available database of 1,148 African Americans from the United States that contains 1,053 mtDNAs of sub-Saharan ancestry. We show that >55% of the U.S. lineages have a West African ancestry, with <41%>coming from west-central or southwestern Africa. These results are remarkably similar to the most up-to-date analyses of the historical record.


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