There's much in his article which merits criticism, but I want to focus on three claims with which Barash confronts his students, and which he apparently believes are devastating to his students' religious beliefs. Barash writes:
As evolutionary science has progressed, the available space for religious faith has narrowed: It has demolished two previously potent pillars of religious faith and undermined belief in an omnipotent and omni-benevolent God.Well, if this is all it takes to demolish his students' faith their faith probably wasn't very well-informed to start with. In the first place, Barash misunderstands the argument he thinks he has refuted. It's not an argument from complexity, it's an argument based on specified complexity, i.e. information. It is information which needs to be explained because the living world is full of it and it's no more a product of random processes such as operate in evolution than a library is a product of blindfolded monkeys hacking away at a computer.
The twofold demolition begins by defeating what modern creationists call the argument from complexity. This once seemed persuasive, best known from William Paley’s 19th-century claim that, just as the existence of a complex structure like a watch demands the existence of a watchmaker, the existence of complex organisms requires a supernatural creator.
Since Darwin, however, we have come to understand that an entirely natural and undirected process, namely random variation plus natural selection, contains all that is needed to generate extraordinary levels of non-randomness. Living things are indeed wonderfully complex, but altogether within the range of a statistically powerful, entirely mechanical phenomenon.
Secondly, it's pretty much an open secret among biologists that the processes Barash cites, random variation and natural selection, cannot account for the introduction of new information into the genome. The most they can accomplish is a reshuffling of the information that currently exists. This allows for variation to arise, like various breeds of dogs from an ancestral prototype, but it doesn't explain how dogs could ever have arisen from a single-celled structure.
Thirdly, the Darwinian processes Barash cites cannot explain how that single-cell ever arose in the first place. There is no more frustrated group of biologists today than those who are seeking a plausible explanation for the origin of life. The reason for their frustration is simple. It's maddeningly difficult to come up with a mechanism which could have operated prior to the existence of living things which could have created the information contained in even the simplest cell, especially since, in our experience information is never produced by anything other than intelligent agency.
Barash goes on to boast that:
A few of my students shift uncomfortably in their seats. I go on. Next to go is the illusion of centrality. Before Darwin, one could believe that human beings were distinct from other life-forms, chips off the old divine block. No more. The most potent take-home message of evolution is the not-so-simple fact that, even though species are identifiable (just as individuals generally are), there is an underlying linkage among them — literally and phylogenetically, via traceable historical connectedness. Moreover, no literally supernatural trait has ever been found in Homo sapiens; we are perfectly good animals, natural as can be and indistinguishable from the rest of the living world at the level of structure as well as physiological mechanism.This is a peculiar argument: Barash is saying that because we are physiologically indistinguishable from other animals therefore there's nothing about us to suggest that we have not descended from other animals, but this is a straw man. No one has ever said that what makes us unique is our bodies. What makes us distinguishable from other animals are not physical traits but mental and/or spiritual traits such as reason, language, art, the capacity for wonder, compassion, morality, a sense of transcendence, a sense of truth, etc. No one knows how these things evolved or why. No one knows how the human mind with its ability to discern meaning, to do math, and to form abstract ideas could have evolved. For Barash to suggest to his students that we're just phylogenetic mammals and that's the end of the matter is to burden them with the misconception that the ontological gulf between humans and other creatures is narrower than it really is.
Barash continues his demolition work:
Adding to religion’s current intellectual instability is a third consequence of evolutionary insights: a powerful critique of theodicy, the scholarly effort to reconcile belief in an omnipresent, omni-benevolent God with the fact of unmerited suffering.This is not the place to discuss the problem of suffering which is indeed vexatious. Suffice it to say, though, that it's not at all clear how human suffering is logically incompatible with the existence of an all-powerful and good God, as Barash implies. The fact that it may be difficult to see why such a God would permit suffering hardly entails the conclusion that such a God doesn't exist.
Theological answers range from claiming that suffering provides the option of free will to announcing (as in the Book of Job) that God is so great and we so insignificant that we have no right to ask. But just a smidgen of biological insight makes it clear that, although the natural world can be marvelous, it is also filled with ethical horrors: predation, parasitism, fratricide, infanticide, disease, pain, old age and death — and that suffering (like joy) is built into the nature of things. The more we know of evolution, the more unavoidable is the conclusion that living things, including human beings, are produced by a natural, totally amoral process, with no indication of a benevolent, controlling creator.
The point, though, to which I wish to call attention is Barash's claim that we are "produced by a natural, totally amoral process." If this is so, then where does our moral sense come from? How does a totally amoral process produce the universal belief that some things are objectively wrong to do? And if a totally amoral process did give rise to such beliefs why do we feel compelled to obey them? How can blind, impersonal processes impose upon us a duty to behave in accord with them? It's like thinking that it's somehow wrong to go up in a hot air balloon because we'd be offending the law of gravity.
So here's the syllogism with which Barash's students should confront him: If man is the product of a totally amoral process then no objective moral duties exist. However, objective moral duties do exist (e.g. a duty not to abuse children, or to cheat the elderly out of their life savings). Therefore, we are not the product of a totally amoral process.
Now having a student raise that argument would certainly make Professor Barash's talk a lot more interesting.