Ridley Scott's Prometheus imagines the origin of humans to be an experiment conducted by hyper-civilized aliens in some remote part of the galaxy. Enough of this fantasy. It is old and profoundly unscientific. It is old and childishly anthropocentric. If we need to film fantasies, then let them rise like mists from the solid ground of what we really know about the world and our history in it. We all come from Africa. We radiated from this one point. The shaper of the human brain, the most complicated organ known to us, is the African geography, environment, and climate. Nothing like it came out of Europe. To visit Africa is to visit the land of your wonderful intelligence.

A new, comprehensive review of humans' anthropological and genetic records gives the most up-to-date story of the "Out of Africa" expansion that occurred about 45,000 to 60,000 years ago.

This expansion, detailed by three Stanford geneticists, had a dramatic effect on human genetic diversity, which persists in present-day populations. As a small group of modern humans migrated out of Africa into Eurasia and the Americas, their genetic diversity was substantially reduced.