What is our fate?

We live in a diverse world, where races are very much intergrated within every country. There may be more diversity over the others within locations, nonetheless I don't think you can find a state or country that resides only its "original" race. My question is: why is it that humans always seem to have the innate nature to migrate? We all know how America has come to be. The American Indians were chased out; the African Americans were enslaved; and every other race, who has come after the original settlers, was simply made inferior. Consider warfare and domination in which humans try to take over states or countries. Is it because the grass is always greener on the other side? Or is it because we cannot defy our nature to conquer (and overcome)? Would it ultimately lead humans to finally see that we're all just one big race? Or would intergration cause more segregation, hate crime and other social disorder? Or, perhaps somewhere in between, that we'll come to see that "the best fit is never another monkey's monkey" (quote from Mystery Cookie)?