Evolutionary advantage of curves

[Tank]

Narrow hips = small pelvic opening = increased potential of birth difficulties.

But saying someone either has "narrow" hips or "wide" hips is a bit misleading. You can't actually see the parts of the pelvic structure that have much to do with delivering a baby. Me, for instance, I'm a pretty "hippy" looking person, but I broke my tail bone delivering my son because my pubic bone was too close to my spine.



The top parts in this picture are mostly what we see of hips, versus the opening near the base of the spine which is where the baby passes. It could have been totally possible for men and women to evolve with the exact same hip "aesthetic", but with women having the wider pelvic opening. If you think about it, from an evolutionary perspective, that would have been the path of least resistance. But instead you see women with a more "flared" and "outwardly hippy" appearance. I think there has to be some kind of external reason for this difference - either, like some other people have said, because somewhere along the way it because a desirable trait for reproduction or because the hip shape itself actually serves some evolutionary purpose (my proposal: carrying young children  ).

Valid point.

[xSilverPhinx]

I just thought it'd be a neat idea to throw into the mix of considerations 

Makes me wish some scientist would start a web site where laypeople could post suggestions for further research.

I agree, there are some people that make good intuitive leaps around.