In the context of archaic populations (African like pygmies Mbuti/Biaka, !Kung/San, Bantu: Zulu-Xhosa, Alur/Nande/Hema: Indian: Irula/Madiga) vs. Europeans, the key is insertion polymorphism: Ancestral state (older, "no insertion"): This is the original genome variant (present in ancestors, such as chimpanzees, before insertion). More common in sub-Saharan Africa (average frequency of insertion ~0.42-0.46, i.e. no insertion in ~54-58% of alleles: e.g. in Mbuti/Zaire pygmies ~0.77-1.0 insertion, but in !Kung/San and some Bantu lower). In India (Irula/Madiga) average ~0.54-0.95, with polymorphism. These populations retained ancestral variant, because Africa has the highest genetic diversity (less migratory bottleneck). Derived state (younger, "presence of insertion"): This is the variant after the Ya5NBC157 insertion. Fixed (frequency ~1.0, or 100%) in Europe and Asia - all Europeans have an insertion on both copies of the chromosome (+/+ homozygotes). Europeans "do not have" the ancestral deficiency - they lost it through genetic drift after leaving Africa (~70,000 years ago). "The gene that the listed populations have, but Europeans don't" is an ancestral allele (no insertion), older by ~2 million years (the age of insertion came later). Europeans have only derived insertion, which is due to bottleneck - a smaller gene pool of migrants from Africa, where the insertion became fixed.