Out of Africa

Every human alive today, all 8 billion of us, descends from a population that lived in Africa roughly 200,000 to 300,000 years ago. This isn't philosophy. It's genetics.

When scientists compare DNA from people across the globe, a clear pattern emerges: African populations have the most genetic diversity. The further from Africa you sample, the less diversity you find. That is exactly what you'd expect if small groups left Africa and carried only a fraction of the original gene pool with them.

Consider the technology available: no boats (at first), no maps, no metal tools. Yet within about 50,000 years of leaving Africa, humans had reached nearly every habitable landmass on Earth.