“The time has come to take seriously the fact that we humans are modified monkeys, not the favored Creation of a Benevolent God on the Sixth Day. In particular, we must recognize our biological past in trying to understand our interactions with others. We must think again especially about our so-called ‘ethical principles.’ The question is not whether biology—specifically, our evolution—is connected with ethics, but how.
As evolutionists, we see that no justification of the traditional kind is possible. Morality, or more strictly our belief in morality, is merely an adaptation put in place to further our reproductive ends. Hence the basis of ethics does not lie in God’s will… In an important sense, ethics as we understand it is an illusion fobbed off on us by our genes to get us to cooperate. It is without external grounding… Ethics is illusory inasmuch as it persuades us that it has an objective reference. This is the crux of the biological position. Once it is grasped, everything falls into place.” [Ed: Or not?]
Ruse, Michael. 1995. “Evolutionary Ethics: A Defense.” Biology, Ethics, and the Origins of Life. ed. Holmes Rolston, III. p.89-112, Boston: Jones & Bartlett Publishers, pp. 93 and 101. And, Michael Ruse and E. O. Wilson, “The Evolution of Ethics,” in Religion and the Natural Sciences: The Range of Engagement, ed. J. E. Hutchingson, Orlando, Fl.:Harcourt and Brace, 1991. Quoted here.