Modern Africans harbor foreign DNA from unknown archaic species. This DNA differs from Neanderthal and Denisovan DNA. Interbreeding occurred 20,000-50,000 years ago in Africa. Foreign DNA appears in pygmies, Hadza, and Sandawe. No trace of this DNA in present-day Europeans. Archaic group confined to Africa. Humans shared Earth with cousin species for over 150,000 years. Interbreeding produced viable offspring across hominid groups. Pygmies average under five feet due to identified genes. African groups show 3 million new genetic variants. Africa holds vast human genetic diversity. Neanderthals left DNA in Europeans. Denisovans left DNA in Pacific Islanders. Mystery Africans resembled modern humans enough for reproduction. Modern humans outcompeted and conquered archaic groups.