Morality is a form of cooperation, but it evolved to help individual groups of humans. It can be applied between groups of humans, but that is not required.
For example, codebreaker believes that only creationists are going to heaven. In fact, he revels in his fantasy of Gould burning in hell. Yet, he would be horrified by the idea of himself burning in hell, with his skin blistering and flesh melting for all time. He can do this because he only applies his morality to his group of people, the creationists. Anything is ok for anyone else. This is exactly what Genghis or Hitler did. Morality, in humans, only seems to apply to the group that you are in.
Is this good, or just? No. It is just true.
In a universe governed solely by the mechanisms of random evolution, cooperation is both an evolved behavior, and also an engine of evolution. You're probably correct that in such cases "morality" is definable only in terms of how one adheres to the evolved methods of cooperation.
And you're probably also correct that cooperation is not a strict evolutionary requirement, nor are the means or goals of cooperation constant -- which says that morality is only a relative concept, grounded in random mutation.
But note that in saying this, one must surrender any means of differentiating between right and wrong, except perhaps for the strict utilitarian criteria embodied in evolutionary theory. From that perspective, the only thing wrong with Soviet Communism was that it didn't work. The present Chinese tyranny cannot be morally condemned, because it has yet to fail.
By the same token, Athenian democracy is morally inferior to Spartan despotism, as history shows the latter to have been far more successful than the former.
Morality, in humans, only seems to apply to the group that you are in.
That is a false statement -- Christian morality, for example, teaches precisely the opposite idea, even if the practice sometimes falls short.
Be that as it may, your postulated morality does allow one to express a preference for a particular outcome -- indeed, "cooperation" implies that a group of people can share and pursue a common preferred result.
But again, this does not translate into any universal concept of right or wrong. Indeed, this approach basically denies the possibility of "unalienable rights," especially for individuals; not to mention any pretense to standards of proper behavior.
This highlights the severe logical difficulty underlying the philosophy of, say, Ayn Rand and her libertarian followers here on FR, who quite vocally claim to have access to a set of absolute moral principles.
Gould's contribution to the fray was in putting forth an attractive (if ultimately indefensible) case for an atheistic view of evolution, the logical end of which we have addressed above. It's interesting, therefore, that many of the people who lionize his scientific positions on threads like this one, are the same ones who loudly complain about the practical results of his theory on political threads.