I love the quote from Stephen Pinker (who is one of the high-profile evolutionary psychologists, along with Richard Dawkins, who contends that about 50% of our behaviour/personality is genetically inherited...) He says that our genome stabilized on the African savannah many thousands of years ago, so, basically, any characteristic that resulted in perpetuation of "the species" became fixed in us around that time...
HOWEVER, since that time, there have been so many layers of culture dolloped on us that whether something is "conducive to the perpetuation of the species" matters not one jot to the majority of us: it certainly mattered when there were only a hundred of us roaming the bush, but I'd say that nowadays we don't have any worries about the species dying out(!), so, frankly, who cares...
Anyway, lots of things are not conducive to perpetuation of the species -- being butt ugly for example... should we ban that too???
Actually, Pinker's point was that we don't have to obey nature; we can think for ourselves. For example, we can wear clothes, even in hot climates :-) . Or we can refuse to hit someone even when our instincts are telling us to... Pinker, who "remains childless", and intends to keep doing so, says that if his genes don't like it, "they can go jump in the lake..."