[shubi]

Yes, it is like a Ring Species group, but does not rise to the level of speciation. Interbreeding is evolution, when populations change genetic characteristics.

The alleles for dark skin are more prevalent where filtering the sun is a survival advantage. You see, since there is a selection against darker skins in the North, eventually lighter skins prevail (as long as people are living outside). Today it might not work exactly the same way since we have Vit D supplements and many people never see sunlight in the modern world.

But there was a gradiation present prior to the relatively recent historical events you cite. For instance, you might site the example of the Eskimos in Alaska. But these are a recent immigration within the last 70,000 years over the land bridge that existed in the vicinity of the Bering Strait.

It took a lot longer than that for natural selection to turn into the gradient we see. But I would bet there is selection going on for lighter skin in native eskimo populations, especially if compared to native south american populations.

[UnbelievingScumOnTheOtherSide]

It took a lot longer than that for natural selection to turn into the gradient we see. But I would bet there is selection going on for lighter skin in native eskimo populations, especially if compared to native south american populations.

What you are saying is that modern man's migration south to north was 75,000 years ago (all Black from Africa) and then migration was strictly west to east or not at all (while Blacks turned into Asians and White people, even in places as close and sunlit as Egypt where no desert barrier existed as recently as 6000 years ago) until historic times when south to north migration suddenly resumed. Does that sound rational?

[Elsie]

All that sunlight grows TREES which shade the pre-humans, eh?