The debate is less about the truth than about how to handle it. For those who believe that morality comes straight from God the creator, acceptance of evolution would open a moral abyss...but I am wary of anyone whose belief system is the only thing standing between them and repulsive behavior. Why not assume that our humanity, including the self-control needed for livable societies, is built into us? Does anyone truly believe that our ancestors lacked social norms before they had religion? Did they never assist others in need, or complain about an unfair deal? Humans must have worried about the functioning of their communities well before the current religions arose, which is only a few thousand years ago. Not that religion is irrelevant...but it is an add-on rather than the wellspring of morality.de Waal gives an engaging review of his observations on primate behavior that show clear evidence for moral and altruistic behaviors that can not be linked to simple "selfish gene" models and he ends with this comment about monkey and chimpanzee behaviors:
...they strive for a certain kind of society. For example, female chimpanzees have been seen to drag reluctant males towards each other to make up after a fight, removing weapons from their hands, and high-ranking males regularly act as impartial arbiters to settle disputes in the community. I take these hints of community concern as yet another sign that the building blocks of morality are older than humanity, and that we do not need God to explain how we got where we are today. On the other hand, what would happen if we were able to excise religion from society? I doubt that science and the naturalistic worldview could fill the void and become an inspiration for the good. Any framework we develop to advocate a certain moral outlook is bound to produce its own list of principles, its own prophets, and attract its own devoted followers, so that it will soon look like any old religion.