@BowsacNoodle @Kirino @WashedOutGundamPilot @moomin > I read something long ago about 9/10 people never going more than 20 miles from their birth throughout history. It would make sense that there'd be a ton of 2nd, 3rd, and even 1st cousin marriages based on that number. It would also explain how distinct features become so common in a people group.

I follow you so far.
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>that ultimately adds fresh genes to the mix here and there. It makes sense.
It doesn't to me. What's "fresh" about different? Why are the genes from ppl that DON'T live there better than the genes from ppl that DO? Genes don't rot... And you would still have natural selection in a small population. So what makes it necessary to "trade" genes with the next tribe over, who has THE SAME PROBLEM? I just don't understand this shit no mo, and I took human genetics classes like woggy, fwiw