I'm not saying this is what happened and I'm not here even trying to argue against common descent. The point is that Giberson and Collins want to rise above the debate over evolution by simply proclaiming that no serious thinker would even engage in that debate given how well, in their view, the theory is now established. And yet, at the one place where they do consider actual evidence for common ancestry, it is less than compelling. Moreover, at no place do they show how natural selection has the creative power they ascribe to it. This is a defect shared in their previous work (Giberson's Saving Darwin and Collins' The Language of God). Throughout The Language of God, for instance, evidence for common descent is equated with evidence for the power of natural selection. But in fact, there are design theorists (e.g., Michael Behe) who accept common descent but reject natural selection as the primary engine of evolution.

Because Giberson and Collins assert that natural selection is such a powerful mechanism for driving evolution—and one that admits no reasoned dissent—it's worth recounting here briefly why the intelligent design community is so skeptical of it. It's not, as theistic evolutionists often suggest, that we have a desperate need to shore up faith and morality and are using ID as our instrument of choice to accomplish that end. Rather, it's that natural selection is, in essence, a trial and error tinkering mechanism for which all evidence suggests that its power is quite limited. Trial and error works fine when you have something that's functional and are trying to enhance it or adapt it to a new situation.

But for natural selection, as a trial and error mechanism, to traverse vast swatches of biological function space, we need to see an extended series of small gradual structural changes (under neo-Darwinism, these are genetic mutations leaving effects at the phenotypic level) that continually improve, or at least maintain, function, with evolving functions and evolving structures covarying and reinforcing each other. But we know of no detailed testable (macro-)evolutionary pathways like this in any field, whether in the evolution of living forms or in the evolution of language or in the evolution of technologies. In fact, when we can trace such evolutionary pathways, we find that significant change happens in creative leaps, not via trial and error tinkering.

Throughout The Language of Science and Faith, Giberson and Collins attempt to broaden evolution's appeal to the wider Christian, and specifically evangelical, community. Theistic evolution is already well entrenched at Christian colleges and universities (in fact, it is the default position and one would be hard pressed to find a CCCU school that will hire an outspoken ID proponent, to say nothing of a creationist). But among the unwashed masses (of which I count myself a member), evolution is widely doubted and even condemned. Giberson and Collins, convinced that their theory is right, are certainly in their rights to argue for it. As already noted, there's nothing wrong with selling one's ideas. But it needs to be done honestly, and that's just what I don't find in this book.