quality:correction, structural:reformatting
Genome-wide studies

Correspondingly, Montinaro et al. (2014) observed that around 50% of the overall ancestry of African Americans traces comes from a population similar to the Niger-Congo-speaking Yoruba of southern Nigeria and southern Benin, reflecting the centrality of this West African region in the Atlantic slave trade. The next most frequent ancestral component found among African Americans was derived from Great Britain, in keeping with historical records. It constitutes a little over 10% of their overall ancestry and is most similar to the Northwest European ancestral component also carried by Barbadians. Zakharia et al. (2009) found a similar proportion of Yoruba-like ancestry in their African American samples, with a minority also drawn from Mandenka and Bantu populations. Additionally, the researchers observed an average European ancestry of 21.9%, again with significant variation between individuals. Bryc et al. (2009) note that populations from other parts of the continent may also constitute adequate proxies for the ancestors of some African American individuals; namely, ancestral populations from Guinea Bissau, Senegal and Sierra Leone in West Africa and Angola in Southern Africa. An individual African American person can have over fifteen African ethnic groups in their genetic makeup alone due to the slave trade covering such vast areas.