I explained my theory of cultural evolution. After leading 17 expeditions to explore ancient mysteries, I noticed that over time, customs and traditions of successful cultures seem to undergo an unconscious but intelligent natural selection: Practices not good for a society tended to disappear while beneficial ones often survived—no matter how counterintuitive they may seem. I remember a story about a tribe in sub-Saharan Africa that cooked over open fires inside their huts. The huts filled with smoke that the villagers breathed. When a Peace Corps worker saw this he reasoned that the people’s
...more