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.

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.

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.

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.

I CONCLUDE The Talk by saying that, although they don’t have to discard their religion in order to inform themselves about biology (or even to pass my course), if they insist on retaining and respecting both, they will have to undertake some challenging mental gymnastic routines. And while I respect their beliefs, the entire point of The Talk is to make clear that, at least for this biologist, it is no longer acceptable for science to be the one doing those routines, as Professor Gould and noma have insisted we do.

Despite these three evolutionary strikes, God hasn’t necessarily struck out. At the end of the movie version of “Inherit the Wind,” based on the famous Scopes “monkey trial” over a Tennessee law prohibiting the teaching of evolution, Spencer Tracy’s character, fashioned after the defense attorney Clarence Darrow, stands in the empty courtroom, picks up a Bible in one hand and Darwin’s “Origin of Species” in the other, gives a knowing smile and claps them together before putting both under his arm. Would that it were so simple.