@Philip Thanks for the comments.
And one cannot say, in a purely materialistic world, that there is any one CORRECT morality - not if all morality simply evolved. In a purely materialistic universe, who can authoritatively assert that the predator murderer / cannibal's morality is any better or worse than the morality of a peace-loving vegetarian. Kill a man, kill a cow - in a purely materialist world - not one bit of difference. In such a world, there is NO good or bad - there simply IS! There are outcomes - with winners and losers. At some point, neither would continue to exist - unequal in life, but equal in the end. Ruthless, brutal, but simply the way things are - that's the materialist universe, of which all moral debates are rather silly!
Well, the question is how you define morality. You ask for " one CORRECT morality" that is the same everywhere, that is an absolute moral. I agree with you that it is not possible to have an absolute moral in a materialistic/naturalistic world (even if there are lot of philosophers that don't agree). But you also seem to assume that if there is no absolute morality then there is no morality at all. Then you don't use the usual definition of morality. Merriam-Wester says " Morality: a doctrine or system of moral conduct ". I wrote " Morality is a set of rules that governs interindividual interactions." It's not at all "silly" to discuss morality even if there is no absolute morality. Different cultures have different moral systems. They are similar in many respects because of our common inherited morality developed through evolution but different because of different environments and histories.
The idea that morality is passed on because it has mutual societal benefits of peace and harmony, cooperation - really, while there are benefits in that approach, it's merely a result of whatever numbers of people agree with that approach, and that have the individual / collective ability to pursue it.
What passes on the morality of a group or society is how successful the group is when competing with other groups. If the group wins over other groups their code of morality will spread too and their concepts of right and wrong will take over. If a group sustains a morality that makes is praiseworthy to fight and sacrifice ones life the group has a greater chance to survive than if everybody just wants to sing and laugh.
But for many, especially those in positions of great power and the ability to dominate others, take a different approach - which is the Darwinian survival of the fittest - that the fittest take whatever they are able to, because it so suits their motives and desires.
It seems that you don't understand the evolution theory. Darwinian survival of the fittest is not about personal power and gain, it is about how many descendants you get and how they survive and how many descendants they get etc. Dawkins has coined the expression The selfish gene; that explains what's important.
PS I haven't lot of spare time and will not always respond rapidly but some day I will answer your questions that started this thread.
PPS Is there a spelling check and how do I find it?