The Long Way Back to Ourselves

1.9

The Great Migration: How Humanity Took Over the Planet

This episode follows humanity's spread, opening with a crossing of open ocean into Indonesia roughly 65,000 years ago, requiring boats and the belief that land existed beyond an invisible horizon. It cites geneticist David Reich to correct the assumption that skin color tracks deep ancestry: genetic diversity within Africa exceeds that of the rest of humanity, since everyone outside Africa descends from a small founder population. It also walks back the claim that a Toba volcanic eruption around 74,000 years ago wiped out most of humanity, since ash layers in East Africa and India show no break in human activity. Rather than bodily adaptation, the episode credits sweating, endurance running, and clothing and fire.