Because their skin changed for some reason.Religion is real,don't doubt it.
Their skin color and culture changed and they spread out all over the world?
Skin color depends on where you live because it adapts to the environment. For example, Africans have darker skin so they won't get sunburns as easily in their hotter environment. As for culture, that developed over the years as humans spread out throughout the Earth. See? Science and religion CAN coexist. :)
Everything changes, for the better or worse. who's to say one religion is better then the other? no one.
Ha, my Social Studies teacher was once a substitute at a really religious school, and he wasn't allowed to teach anything that contradicted the Bible. Anyway, one kid in his class goes "Sir, how long have Aborigines lived in Australia?" and the teacher goes "X Thousand years" (Sorry, I forget the number) And then the kid goes "But how did they survive the flood?"
Because it is yet another story in a book full of fiction.