I have a genuine question: In a world fully connected where cultural and national boundaries sexist but travel is for the most part free, and immigration between countries is exclusive and total, meaning if you go to X country you adopt X culture, wouldn't humanity tend to become a single race of mutts?
From the perspective of genetic fitness, wouldn't a mutt be the most adaptable to the greatest number of situations as compared to one specific subspecies?
A grain of white sand is symbolic of a genetic trait that is optimal for climates with less sun & a grain of black sand is symbolic of a genetic trait that is optimal for climates with more sun
Imagine mixing two jars of pure black sand and pure white sand together then letting natural selection fix things by moving one grain of sand every 18 to 45 years at a time until pure white sand is achieved in a less sunny environment or pure black sand is achieved in a more sunny environment
White people were already naturally selected to be optimal for Europe and Black people were already naturally selected to be optimal for Africa
If you mix them you will have a mixture of traits that are suboptimal for Europe and also suboptimal for Africa
It would take thousand of years to partially repair the damage
And if there is a cataclysm humanity might become extinct in that region before then
@DoubleD
Now if welfare as a reward for undesirable behaviors was eliminated natural or artificial selection could work to improve the next generation by weeding out the bad offspring that were produced by race mixing or without race mixing
But as long as welfare is a reward for genes that are harmful to society each generation will get worse for humanity as a whole with or without race mixing