Four West African populations show archaic introgression. Ancestry ranges 2-19% from archaic diverged before Neanderthal-modern split. Yoruba and Mende genomes map high-frequency archaic segments. Segments indicate adaptive introgression targets. Eurasians lack this specific archaic source. Neanderthal DNA found in some Africans. West African clade mixes modern human and archaic. Archaic component equals 2% in some models. Deep modern human adds 10-29%. Claim specifies Homo erectus or habilis unproven. No reference archaic genome exists. Finding controversial due to statistical models. Sub-Saharan genetic diversity exceeds rest of world. Non-Africans form subset of African DNA variation. All modern humans carry some archaic DNA.