Human evolution, or anthropogenesis, is the origin and evolution of Homo sapiens as a distinct species from other hominids, great apes and placental mammals. The study of human evolution encompasses many scientific disciplines, including physical anthropology, primatology, archaeology, linguistics and genetics.
The term "human" in the context of human evolution refers to the genus Homo, but studies of human evolution usually include other hominids, such as the Australopithecines. The genus Homo had diverged from the Australopithecines by about 2.3 to 2.4 million years ago in Africa. Scientists have estimated that humans branched off from their common ancestor with chimpanzees - the only other living hominins - about 5â€“7 million years ago. Several species of Homo evolved and are now extinct. These include Homo erectus, which inhabited Asia, and Homo neanderthalensis, which inhabited Europe. Archaic Homo sapiens evolved between 400,000 and 250,000 years ago.
The dominant view among scientists concerning the origin of anatomically modern humans is the "Out of Africa" or recent African origin hypothesis,which argues that H. sapiens arose in Africa and migrated out the continent around 50-100,000 years ago, replacing populations of H. erectus in Asia and H. neanderthalensis in Europe. Scientists supporting the alternative multiregional hypothesis argue that H. sapiens evolved as geographically separate but interbreeding populations stemming from a worldwide migration of H. erectus out of Africa nearly 2.5 million years ago.