The Booty Pose: Necessary?

Add some alcohol, a bunch of women, a camera and stir.
Sooner or later, it will famously pop up (or toot down, I should say.)
The relentless staying power of the booty pose.
Why so popular? I mean, beside the fact that the fleshiest organ on the human body is bent all over in your face? I mean it is also the excrement depository for the body, but that's enough about anatomy. How about a simple, arms-folded, standing-straight-up smile? Women are endowed with beautiful smiles, frontal views with supple breasts, but the booty pose is the most popular one at the club. Why? Is it a not-so-subtle invitation to come hither? Are women sending estrogen smoke signals to men when they toot over like so? Whatever the reasons, the booty pose has shown elastic dexterity through the years.