There is a presumption that this was the only time this had happened. We cannot rule out the possibility that humans migrated out of Africa 80k years ago to reconquer the world. I seem to recall an article in a mainstream magazine, I think it might have been "New Scientist" which identified a point n our prehistory when we almost went extinct as a species. I recall, perhaps inaccurately, that our numbers were about 15,000 before we started gaining enough members to be ensured of species survival. This I recall had to do with the eruption of the Toba supervolano in Indonesia,

I seem to recall this genetic bottleneck occurring, based o genetic studies, around 70k years ago. Obviously the dates of 80k and 70k years ago have to be taken with a grain of salt since we can only approximate. I do remember that there is also a suggestion that our numbers dipped to about 2 thousand for about 1000k years until about 40k years ago.

I wonder how many times we have gone out and repopulated the world from a species near extinction, and more importantly, are we going to have to do it again soon?

Howdy Metamagic

There are a number of theories. Yep there is a theory of multiple waves of humans-I think it was more a movement olike molasses. No one was aware they were moving. They just headed in different direction a few miles away every few years and drifted along.

Yeah there seems to have been a bottle neck and that is probably where the mutation for greater intelligence/social cooperation came to the fore.

Fantastic stuff.