[blam]

"I was told that Africa has more genetic diversity than the rest of the world combined."

The Toba eruption 75,000 probably is responsible for killing most of the other genes outside Africa. Albeit, the Neanderthals and apparently the 'Hobbits' on Flores suevived that eruption. It was the 'nuclear-winter' effect that did the killing, btw.

[Varda]

The human race seems to have had some really close calls. I think it's possible other Homo erectus populations survived too (New World maybe).