6 Answers

Probably because they stayed in Africa.

Weren't Neanderthals discovered in Europe?

Maybe they could not afford 'LEVI'S' LOL.

Maybe we didn't all walk out of Africa. 

 Makeup of all humans has evolved over time due to sun - ultraviolet exposure, food we eat , and climate conditions. Genetics will change. Some people just are not lucky in the gene pool as others as an example.  As people evolved from "apes" genetic and hormonal changes occurred to what we are today. I kind of understand what you are saying , but I don't think it is entirely correct. We all can be traced back to seven black African descent women and that's all it can be traced back to at this time , from what I have learned. Heterosis - a percentage difference in variation due to additive genetic differences - is whats important in improving evolution of all living plant and animal breeds.

good question.

Ducky

Good answer. :)