Conservatives have more self-control

[Thumpalumpacus]

I'm making an obvious application of natural selection, one that evolutionists are generally afraid to make for some reason.

You're making an incorrect application of natural selection, based on the mistaken premise that physical strength defines the fittest.

Furthermore, sexual dimorphism is almost certainly a function of sexual selection rather than natural selection -- much the same way as peacocks evolved their tails not due to survival pressures, but because for whatever reason, peahens preferred them. Human females being more gracile probably has nothing to do with individual survival statistics, and more with human male preferences for smaller mates, or human female preferences for huskier men -- or more likely, a combination of both.