What happens if your parents are first cousins? You don’t have as many ancestors as the article assumes. And it’s only now that people are so connected that suc

What happens if your parents are first cousins? You don’t have as many ancestors as the article assumes. And it’s only now that people are so connected that such a situation can arise, but earlier people used to marry mostly within their local communities, so each spouse would share many of the same ancestors as the other.