I already demonstrated yesterday how your central justification of this - that segregation is necessary to maintain diversity - is false because your example of the way that alleles can be "extinguished" is
extremely improbable in populations that are large enough where inbreeding is not a factor.
Now I see your next to last concluding sentence here:
Without this freedom, no matter where we travel on this planet in the future, the people will all look generally the same.Again, this is completely
false. Hybridization
cannot produce uniform "blending" throughout entire populations in the absence of natural selection. This is because of something that you would be aware of if you had bothered to learn anything about genetics before imagining yourself to be an expert, known as
Hardy-Weinberg Equilibrium.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/H/Hardy_Weinberg.htmlConsider our example from yesterday of the two equal populations of people, one being homozygous for the dominant brown eye trait, the other being homozygous for the recessive blue eye trait. Because there is no known evolutionary advantage to having either brown or blue eyes, the resulting interbred population will be at Hardy-Weinberg Equilibrium. It will
not result in a population that looks "generally the same". Instead the population will always and for every succeeding generation contain approximately 75% brown eyed people
and 25% blue eyed people.
The blue eye trait will never be "extingished" from the hybrid population.