SRS -- I'd be interested in that book title if you get the chance to get around to it....
And, alas, some ideas about WHY! Yeah, I had thought of (read about) that, too, the whole sex for the carrying on of genes and the food thing (tweed and DW). Sounds plausible, for sure.
But then, why do most of us prefer to LOOK at those that don't jiggle as much? I get the whole thing about it not mattering once you love someone, and it is what is on the inside, and someone to BE with is different than someone to LOOK at, or someone just for a one nighter....
Why the discrepency? Any suggestions out there?