Not only are the Yoruba people of Nigeria high in rh negative blood, they also carry Neanderthal DNA which is rare for Africa.
Examining the origin of rh negative blood and Neanderthal DNA within the Yoruba population may help determine the origin of rh negative blood.
According to a 2017 study, Yoruba people have ~31% prehistoric “Basal Human” (BE) admixture.
Neanderthal-derived ancestry is absent from most modern populations in sub-Saharan Africa, while Denisovan-derived ancestry is absent from modern populations in Western Eurasia and Africa. However, in Africa, archaic alleles consistent with several independent admixture events in the subcontinent have been found. It is currently unknown who these archaic African hominins were.