there is this theory called "hybrid vigor"
It states that different races have strengths. If you mix these races together, the offspring will have the strengths of both races.
if blacks are good at running, and the Chinese are good at math, maybe you create offspring that's good at both.
But, this is rare. You will likley just create a kid that can't run or do math.
Race mixing usually creates weaker offspring.
A positive example might be different ethnicities of the same race that mix.
almost all of us have a lot of race mixing anyway, don't we?
Depends what you mean.
Are white people a mix of different European ethnicities? Sure. You have white people that are part Italian/Swedish/Russian and so on.
But that person is still 100% white.
Is everyone half black or half Asian or something? Definitely not. Although it's more common nowadays.
@ToyotaTime
maybe the darker skin color and coarser dark hair of southern europeans comes from an infusion of negroid or arab blood or both