This article is from Greg Koukl of Stand to Reason. He is answering the question of whether observations of social behaviors in animals is an adequate ground for a robust prescriptive moral standard. (The “Wright” mentioned in the quote is Robert Wright)

Excerpt:

When morality is reduced to patterns of behavior chosen by natural selection for its survival value, then morality is not explained; it’s denied. Wright admits as much. Regarding the conscience he says:

The conscience doesn’t make us feel bad the way hunger feels bad, or good the way sex feels good. It makes us feel as if we have done something that’s wrong or something that’s right. Guilty or not guilty. It is amazing that a process as amoral and crassly pragmatic as natural selection could design a mental organ that makes us feel as if we’re in touch with higher truth. Truly a shameless ploy.[11] [emphasis mine]

Evolutionists like Wright are ultimately forced to admit that what we think is a “higher truth” of morality turns out to be a “shameless ploy” of nature, a description of animal behavior conditioned by the environment for survival. We’ve given that conduct a label, they argue. We call it morality. But there is no real right and wrong.

Does Bongo, the chimp, actually exhibit genuine moral behavior? Does he understand the difference between right and wrong? Does he make principled choices to do what’s right? Is he worthy of blame and punishment for doing wrong? Of course not, Wright says. Bongo merely does in a primitive way what humans do in a more sophisticated way. We respond according to our genetic conditioning, a program “designed” by millions of years of evolution.

The evolutionary approach is not an explanation of morality; it’s a denial of morality. It explains why we think moral truths exist when, in fact, they don’t.

Do observations of patterns of behavior in different societies and different times create any moral obligation in individuals to conform to those arbitrary patterns of behavior?

Koukl continues:

This observation uncovers the most serious objection to the idea that evolution is adequate to explain morality. There is one question that can never be answered by any evolutionary assessment of ethics. The question is this: Why ought I be moral tomorrow?

One of the distinctives of morality is its “oughtness,” its moral incumbency. Assessments of mere behavior, however, are descriptive only. Since morality is essentially prescriptive–telling what should be the case, as opposed to what is the case–and since all evolutionary assessments of moral behavior are descriptive, then evolution cannot account for the most important thing that needs to be explained: morality’s “oughtness.”

The question that really needs to be answered is: “Why shouldn’t the chimp (or a human, for that matter) be selfish?” The evolutionary answer might be that when we’re selfish, we hurt the group. That answer, though, presumes another moral value: We ought to be concerned about the welfare of the group. Why should that concern us? Answer: If the group doesn’t survive, then the species doesn’t survive. But why should I care about the survival of the species?

Here’s the problem. All of these responses meant to explain morality ultimately depend on some prior moral notion to hold them together. It’s going to be hard to explain, on an evolutionary view of things why I should not be selfish, or steal, or rape, or even kill tomorrow without smuggling morality into the answer.

The evolutionary explanation disembowels morality, reducing it to mere descriptions of conduct. The best the Darwinist explanation can do–if it succeeds at all–is explain past behavior. It cannot inform future behavior. The essence of morality, though, is not description, but prescription.

Evolution may be an explanation for the existence of conduct we choose to call moral, but it gives no explanation why I should obey any moral rules in the future. If one countered that we have a moral obligation to evolve, then the game would be up, because if we have moral obligations prior to evolution, then evolution itself can’t be their source.

What atheists mean by morality is this: accidental patterns of social behavior designed to promote group cohesion. The behaviors are accidental and they are basically the same as group food preferences, clothing preferences and traffic law preferences. They are MADE UP. Any member of the group who is sufficiently powerful can do as he pleases, because there is no real moral obligation – just customs and conventions. And the only reason not to do what you like is because you might get caught. That’s “monkey morality”. And that’s what atheists mean by morality.

And this is where this evolutionary morality leads atheists like Steven Pinker.

Excerpt:

One of the hippest intellectuals around recently argued in polite company that it’s difficult to defend laws against killing a baby. But he hardly drew a yawn.

Steven Pinker, an MIT psychology professor and best-selling author, presented his argument in a 2 November 1997 New York Times Magazine article entitled Why They Kill Their Newborns. The article attempted to shed light on the “prom mom” phenomenon of recent headlines. Pinker maintains that giving birth and then discarding the newborn in the trash is (of all things) best explained as an indirect result of species-preserving evolutionary adaptations. On this basis, Pinker eventually concludes, “The baby killers turn out to be not moral monsters but nice, normal (and sometimes religious) young women.”

That’s atheist morality.

Or you can read about atheist Peter Singer instead.

Excerpt:

In 1993, ethicist Peter Singer shocked many Americans by suggesting that no newborn should be considered a person until 30 days after birth and that the attending physician should kill some disabled babies on the spot. Five years later, his appointment as Decamp Professor of Bio-Ethics at Princeton University ignited a firestorm of controversy, though his ideas about abortion and infanticide were hardly new. In 1979 he wrote, “Human babies are not born self-aware, or capable of grasping that they exist over time. They are not persons”; therefore, “the life of a newborn is of less value than the life of a pig, a dog, or a chimpanzee.”

That’s atheist morality.

When a person says “I’m an atheist”, what they mean is “Every person can decide for themselves if murdering babies is right for them, and if a society decides that murdering babies is their evolved behavior, then it’s right for them – morality is what people decide it is”. In a time and place where slavery is acceptable, atheists would own slaves. In a time and place where killing your offspring is acceptable, atheists will kill their offspring. In a time and place where killing Jews is acceptable, atheists will kill Jews. They have no external standard of morality, other than the behaviors they observe in the people around them. And they only ape those behaviors to avoid losing social prestige. In their hearts they know that these behaviors are just arbitrary conventions, like driving on the right side of the road. This is what they believe.

Evolutionary ethics is an oxymoron. What atheist mean when they talk about morality is that there is no morality. What they want to talk about is why humans have feelings of obligation to do this or that. If you ask them whether there is anything humans ought to do, independent of feelings and instincts and social conventions, the answer is NO. And feelings are so easily dismissed when they go against self-interest, for atheists. They explain morality away, so that they can jettison moral feelings when they go against their self-interest. “I only feel bad when I kill my child because of genetic programming and social conditioning, but there isn’t anything really wrong with killing my child”. That’s atheist morality.

When an atheist condemns something, he is expressing a personal preference against that thing. And on his atheistic view, the denial of his preference is as warranted as the affirmation of his preference. He may not like rape, so he says “rape is wrong”. But on his own view, the person who says “rape is right” is as warranted in his personal opinion as the atheist is. They think that all talk about what people ought to do is basically opinions of individuals and groups. Slavery isn’t objectively wrong, it’s either “the way we do things in this time and place” or it’s “not the way we do things in this time and place”. It’s all about feelings, on atheism. If it feels good, do it. Just don’t get caught, because then you’ll feel bad. That’s the level of morality that atheists rise to because there is really nothing right or wrong objectively, on their view.

The great moral accomplishment of atheist morality in the last 150 years has been to murder 100 million people. And this is not counting the 40+ million deaths caused by abortion in the US alone, or the 20 million deaths caused by environmentalist alarmism. It also doesn’t count the millions of broken homes caused by the sexual revolution, or the social costs of fatherlessness.