Move any population closer to the equator and over about 10-20 generations their skin colour will change.That's right. If two white parents have a child, it could easily come out black. And if two black parents have a child, it could just as easily come out white. Its a coin toss.
Hair color, hair texture, eye color, skin color, facial features. None of these are biological. They're "social constructs". So are things like lactose intolerance, skin cancer rates, etc.






