Do you believe that our mammalian heritage has equipped us with a sense of morality that is, in some objective sense, correct?
TFA obviously can answer for himself, but I'm butting in, because I have some strong opinions.
No, someone was alluding to the is/ought problem, which is relevant -- Just because our moral intuitions *are* this way doesn't mean they *ought* to be this way.
Or had we evolved differently, could our moral intuitions have been the polar opposite, and what would that mean? If they were truly randomly selected
No, they could not have been the polar opposite. Also, you are not quite right about how evolution works. The principle Darwin came up with was not 'random selection', but 'natural selection'. Assuming our moral intuitions are subject to evolution, selection would favor those moral intuitions that allow one to produce more offspring. So evolution would never favor the moral intuition that "procreation is immoral".
As an interesting (to me) example, when a male lion takes over a pride, he typically kills the cubs. An evolutionary explanation for this is that he's eliminating his rival's genes, and if the females are no longer nursing, they will be fertile sooner, so that he can pass on more of his own genes. I don't know that lions think in terms of morality, but this is a behavior that evolution favors.
When we turn to humans, I don't think anyone is going to publicly state as a moral law that "Men ought to kill one's stepchildren, so that they can produce their own children with their wives."
And yet we know as a fact that stepfathers are about 100 times more likely to kill their stepchildren, than fathers are to kill their children.
Now,
if one were an idiot (and some evolutionary psychologists flirt with this idiocy) one could say that this behavior in humans has an obvious evolutionary rationale. And that, since it is natural, it is moral.
Fortunately, back in question one, I agreed that just because something *is* that way, doesn't mean it *ought* to be that way. Even if this behavior is produced by evolution doesn't mean we should accept it as moral.
, could it be possible even in principle to use intellect to refine them? In other words, can we use our intellect to determine which of our evolutionary instincts are "good" and which are "bad" if the very concept of right and wrong is based solely in those instincts?
Yes, exactly. I don't know that all morality is necessarily entirely generated by evolution, but to the extent that it is, or whether it is or it isn't, we're not stuck with those intuitions and instincts, we can refine them.
(Don't worry. I'm a theistic evolutionist--
Phew! That's a relief.