Re: Actually, it doesn't . . .
It doesn't fall flat, that is.
*A theory here in the U.S. is that the same natural selection applied to East Coast types who got sick of being pushed around and headed West. This explanation falls a little flat when you think about the People's Republic of California though. Seems here that most of the independent minded types wound up in the Rocky Mountain states.
I think that would be from later transitions, such as the airhead Hollywood wannabes who came in later, mixing with the natives and thereby drowning the previously dominant pioneer gene from much of the breed.
;^)
As in Lee's limited analogy, it just depends upon the 2D data you wish to employ,
Dan