Conscience and the Moral Argument as Evidence for the Goodness of God.

[The Grand Nudger]

There is little evidence that it's a natural trait if it were natural why do militaries need to train men not just how to kill but make them want to kill someone they have never met and who has done them no harm? If rape were natural why do humans seem to have such a strong negative reaction to it? this can't merely be cultural indoctrination as even in cultures where there were few written rules in rape there seemed to be a disgust for the act.

That we use rape as a weapon suggests that we innately understand the offense of the act even if a cynical view would suggest that the raping warband doesn't see a problem with it.  Rape the warbands daughters then ask them what they think about that.  As for training people to kill, modern armies have learned that the best way to get people to reliably kill, is not to train them to kill, but to disconnect the lethal act from "killing" first semantically and then cognitively.

Depending on a persons metaethical view, I can see why morality can be thought of as an evolved trait, but I don't think that's the case.  The traits we use to apprehend moral properties are evolved, and evolved for other purposes entirely, but not moral properties themselves.  Those were there to be apprehended before we possessed those traits - we simply weren't moral creatures at the time.  Nothing about rape or killing has changed from before that moment..after that moment, or since.