the world is not that different in some ways than five hundred years ago.. there are literate people and illiterate people, on a large scale. The rise and fall of literate languages is not the same story as the number of people that speak a language, or what colors are on the local police car. It is not popular to speak of this in the USA since there is a "unifying myth" of equality. What the USA did do brilliantly is use markets and local jurisdictions to let warring people settle nearby each other, and thrive. Over time the old ways show up however. Evolution is not practiced uniformly.