In paleoanthropology, the recent African origin of modern humans, or the "out of Africa" theory (OOA), is the most widely accepted model of the geographic origin and early migration of anatomically modern humans. The theory is called the "out-of-Africa" theory in the popular press, and the "recent single-origin hypothesis" (RSOH), "replacement hypothesis", or "recent African origin model" (RAO) by experts in the field. The concept was speculative before it was corroborated in the 1980s by a study of present-day mitochondrial DNA, combined with evidence based on physical anthropology of archaic specimens.