Previous studies of the genetic structure of Afro-Americans have observed a considerable presence of European haplotype R1, among Afro-Americans in North America and the Caribbean. Researchers have assumed that these European genetic signals were probably the result of European males mating with Sub-Saharan African (SSA) females during the Atlantic Slave Trade. Even though this is the usual explanation for the presence of European clades carried by Afro-Americans (AA), recent studies show a high frequency of R haplogroup ancestry among SSAs in West Africa. This study illustrates that the existence of Y-chromosome R1a, and R1b (M-269 and V88) among Afro-Americans may be derived from SSAs instead of Europeans.
Clyde Winters. (2017). DID AFRICAN SLAVES BRING THE Y-CHROMOSOMES R1 CLADES TO THE AMERICAS?; International Journal of Innovative Research and Review , Vol. 5 (2) April-June, pp.1-10/Winters . http://www.cibtech.org/J-Innovative-Research-Review/Publications/2017/VOL-5-NO-2/01-JIRR-001-JUNE-WINTERS-DID-CHROMOSOME.pdf