Evolution gave us the rational mind, hence we are under something of an obligation, evolutionarily speaking, to rise above biologically motivated impulses and baseless social assumptions, in order to affect a better state of being. We are the only species on the planet, so far as we know, with an awareness of our place in the universe. That means that even though we are of nature, we are not bound by it, and thus we waste our potential trying to settle on 'natural' excuses for our behavior. Our mandate is to improve, plain and simple.