Alabama Family Tree 

A family tree in which the parents continue to produce a daughter and a son, that get married to each other and also have a daughter and a son, this continues. The family tree ends up looking like two vertical straight lines next to each other.

He has such a diverse background, almost like the opposite of an Alabama family tree

Alabama Family Tree by Stoven Logg January 11, 2017

Alabama Family Tree 

When a diagonal line is drawn in you family tree inferring that incest has occurred.

"Did you see how ugly that kid is?"
"Yea, I bet he has an Alabama Family Tree"

Alabama Family Tree by Hoophy October 26, 2011