Unless the light skin and occasional red hair of our ape ancestors emerged again when dark skin no longer gave a reproductive advantage due to living in an environment with less sun than Africa?? The argument of course being that as human ancestors lost their body hair covering, dark skin evolved as protection for the skin from the sun -- in the Northern climes, light skin giving more sun exposure provided a reproductive advantage in a environment with limited sun. Always an argument one way or the other, isn't there.
Actually, I am inclined to believe, like you, that a combination of factors, one of which was inter breeding, contributed to the "disappearance" of the Neanderthal.
Well put.