Tony, morality is about “what should be,” not “what is.” You are trying to explain why people do behave in a particular way (because it benefited their survival in the past). But that doesn’t explain why we should continue to behave that way today. First, you are arguing that “right” is what achieves a particular end – in this case, the survival of the most people. But that presupposes that such an end is itself morally commendable. In a Christian worldview, yes, people have innate value to God and are worth saving. But in an evolutionary worldview, how would maximizing the survival of a bunch of chemical accidents be morally commendable? Is it also morally commendable to maximize the chemical reactions taking place in a car engine? Should we try and create as many internal combustion engines as possible since this is morally right? So you are stealing from the Christian worldview when you presume that people have innate value.]

[Second, even if I grant that people have intrinsic worth (which makes no sense on your system), it would still lead to absurd results. If maximizing the survival of people is what determines morally right, then we should outlaw all extreme sports (sky-diving, car-racing, etc.) since these sometimes result in fatalities. In fact, if you really believed that maximizing human survival was what determines “right” then you would want to restrict as much human freedom as possible in order to accomplish this, e.g. along the lines of the robots in “I Robot.” It would be against the law to not have children. etc.]