That is a great question. One that I have put many hours of thought into. In truth, if mankind had continued as one people with a common language, we would have achieved more than we have in a much quicker time frame. As you can see as we bridge the gap of language, we spring forward in leaps and bounds of knowledge and achievement.
In deed, we would have travelled to the outer edge of creation, and who knows, found GOD? That is the reason HE gives us for confusing the language.
Thank you everyone for your ideas...I was thinking more of actual bone stucture, facial shapes lips, eyes, noses small and large frames. Actually the idea of DNA makes sense that God put DNA for all the races into Adam and Eve with His foreknowlege...I hadn't thought about that...