Phylogenetic relationships of human populations in sub-Saharan Africa

This study utilizes the GM/KM immunoglobulin allotype system to elucidate t he phylogenetic relationships of sub-Saharan Africans. The importance of un derstanding the relatedness of these peoples stems from the sub-Saharan reg ion being the possible birthplace of humans. Haplotype distributions were d etermined for 19 populations and compared using chi-square analysis. Publis hed data of other sub-Saharan Africans and representative populations world wide were also added for comparison. Genetic distances between populations were calculated based on haplotype frequencies, and genetic relationships w ere observed through principal components analysis. Data from the GM/KM sys tem showed a genetic homogeneity of the Bantu populations, with some except ions, supporting the possibility of a common origin of these peoples. The M alagasy appeared as a divergent population, most likely due to Southeast As ian/Austronesian admixture, as indicated by the presence of the GM*AF B hap lotype. The Cape Coloured also showed a divergence, with their genetic stru ctures containing Caucasoid and Khoisan contributions. Finally, the Mbuti P ygmies appeared genetically isolated and had the highest frequency of the G M*A B haplotype out of all studied populations.