I once heard the following as a response to Rosenberg on Morality and Evolution:

It seems it is possible for our morality to stem from natural selection and adaptive drives. But if this were really the case, why aren’t our morals more viciously competitive? Natural selection implies a sort of dog-eat-dog competition. So why isn’t this dog-eat-dog mentality morally right to humans? It seems like dog-eat-dog or survival of the fittest socialization would produce in us the determination to overpower and out-live others. One could go so far as to say that we would adopt murder, hurting others, and bullying to be morally right if our morality stemmed from natural selection so as to establish fitness and weed out the less fit and unfit. We would feel it would be right to overpower and bully both the strong AND the weak.
On the contrary, at the very least we feel that it is actually wrong to muder, hurt others, and overpower and bully the weak. It seems contradictory that these viciously competitive things that increase our chances for survival would go against the moral values we currently observe (that those viciously competitive things are wrong).

1. If our morality stems from natural selection, then our morals would be more viciously competitive.
2. Our morals are not viciously competitive (e.g. we do not think murder of socially unfit people is morally right).
3. Therefore, our morality does not stem from natural selection.

Here is my response:

I would object to (1). Specifically, I would object to the claim that natural selection AMONG HUMANS is like a dog-eat-dog mentality that produces viciously competitive morals. Sure, it is survival of the fittest. But humans survive and be fit not by ‘eating’ each other, but by cooperating within groups in order to compete better at the individual level. From this, it follows that rather than murder, hurting people, etc. being adopted as morally right, more cooperative and postive actions would be morally right. What determines survival and fitness is one’s ability to cooperate with others and give others what they want, so that others will do the same back and advance one’s well-being. Plus, as one’ well-being is advanced, the cooperation aspect implies that everyone involved advances their own well-being as well (assuming we are rational beings with good information). In short, the response to above is not a strong objection to Rosenberg.

What do you all think?