EDIT: Wait a minute....Harry and Ginny are distantly related...they're 3rd cousins...and they married...OHMYGAWD THEIR CHILDREN ARE INBRED RESULT.
I lol'd so hard.
This tree friggin rules. I remember the books mentioning that all non-muggleborn wizards are related somehow, but dayum. All these names being interconnected, and then you think "lolinbreeding." It's weird when you see it right in front of you, in black and white.