Evolution of morality discussions are sometimes derailed by well-intended objections such as 1) “Science and morality occupy different domains of nonoverlapping magisteria”, (2) “You are committing the elementary logical error of deriving a moral ‘ought’ from what ‘is’”, and 3) “Deriving morality from evolution produces repulsive nonsense such as the claim that whatever increases reproductive fitness is moral.”
Otherwise well-informed individuals (even moral philosophers!) who are not familiar with the science of morality still commonly bring up variations of these old objections. Philip Clayton and Jeffrey Schloss have pointed out1 that confusion about the science of morality and its ethical implications can be reduced by understanding that there is not just one area of inquiry in evolution and ethics; there are three independent, but related, areas. Those three independent areas of inquiry are listed in the title of this post.
Identifying the specific area of inquiry each of the above objections is motivated by will clarify why none of them are serious impediments to understanding morality as an evolutionary adaptation being culturally useful.
In brief, the three areas of inquiry are:
The “evolution of morality” is the science of understanding the origins and evolution of moral behavior. “Morality from evolution” attempts to derive normative moral knowledge, such as what moral codes ought to be advocated and enforced, from the science of morality. And “morality of evolution” attempts to derive normative moral knowledge from the process of evolution (not from morality as one of evolution’s products).
With our approach defined:
A) The evolution of morality is the science that seeks to explain 1) the biological origins of our ‘moral’ emotions such as empathy, loyalty, guilt that motivate altruism and cooperation and 2) the functional origins (the primary reason they exist in cultures) of past and present enforced moral norms such as versions of the Golden Rule, ‘Christian’ virtues that emphasize humility, ’pagan’ virtues that emphasize leadership, and prohibitions against gay sex and eating shrimp.
It should be uncontroversial that the evolution of morality can be sensible science, though of course people may disagree about what that science is. If anyone claims that the origins and functions of moral behaviors are somehow off-limits to science, then it is up to them to justify their remarkable claim.
Since the science of morality is purely descriptive, it is no more logically capable of making normative claims about what human morality imperatively ‘ought’ to be than is any other branch of science. Thus nonoverlapping magisteria objections are irrelevant to the science of morality.
B) Morality from evolution at first glance might seem limited to producing a big zero since the science of the evolution of morality is merely descriptive; science can only show us what morality ‘is’, not what morality ‘ought’ to be.
But all of science is merely descriptive. Being only descriptive does not mean science can’t help define the best means of achieving whatever a group’s ultimate goals are.
For example, assume groups of people roughly agree on a goal such as increased well-being in the group or perhaps even a religious goal such as maximizing compassion. Once such goals are defined, there is no logical problem with descriptive science informing us how we can best achieve these goals. Therefore, the science of morality can help inform us which moral norms, such as “Do to others as you would have them do to you” ought (instrumental) to be advocated and enforced to best achieve our existing goals such as increased well-being. (Forms of the Golden Rule are useful heuristics for a powerful cooperation strategy called indirect reciprocity from game theory.)
Like the rest of science, morality from evolution is only useful for defining the ‘means’ for achieving separately defined goals. Thus, morality from evolution cannot be the source of the imperative ‘oughts’ that Hume’s “ought from is” fallacy refers to. So when morality from evolution is used only to help define the most effective ‘means’, and not moral ‘ends’, the “ought from is” fallacy objection becomes as irrelevant as it is to the rest of science.
C) Morality of evolution posits moral implications about the process of evolution (not about morality as a product of evolution). This area of inquiry is the source of “the philosophical equivalent of a bad smell” as the philosopher Michael Ruse memorably phrased it. Based on bad science and worse moral philosophy, it led to nonsense claims in the past such as “Whatever increases reproductive fitness is moral.”
More careful science and moral philosophy might rescue this perspective’s cultural utility from the trash bin of history. Until then, this area of inquiry’s chief utility is in pointing out how NOT to apply the science of morality.
1)Philip Clayton; Jeffrey Schloss (editors) Evolution and Ethics: Human Morality in Biological and Religious Perspective (p. 6). Kindle Edition.

In order from the left, Charles Darwin first described the “Evolution of morality”, David Hume first described the ‘ought’ from ‘is’ fallacy which is key to understanding “Morality from evolution”, and Francis Galton, a pioneering advocate of eugenics, which some have argued is morally justified by the “Morality of Evolution”