Right.  That's how come there's no Tay Sach's disease, and no hemophilia.  Oh wait--there is.  My bad.  Actually, we marry across so-called "racial borders" more than any other religious group.  The exceptions are reflections of culture, not religion, particularly among south-Asian Hanafi Sunnis, and even they're getting away from it.  Compared to us overall you're the inbred ones.  Until half a century ago "interracial" marriages were ILLEGAL among you.  Never have been among us.  Sorry, sonny, the more you attempt to teach me about that which I know FAR more than you, the more ridicule you heap on yourself.