That somehow all culture exist in a perpetual state of competition, and the spread/growth of one necessitate the decline of other. While cultures usually can claim a direct ancestry down the ages, the truth is that the cultures and norms existing today in different part of the world is MUCH closer to each other than say their direct ancestral culture 500 years ago - and it happened because cultures are NOT in a competition, rather it adapts to the new technologies and outside cultural influences. As a result the world is closer together than it ever has, and that's a good thing.
