BioLogos and Theistic Evolution: Selling the Product

In any case, Giberson and Collins scrupulously avoid getting into the details of evolutionary theory and deny that it is even questioned among mainstream biologists. That such questioning occurs, even in the mainstream, consider Susan Mazur's The Altenberg 16, subtitled An Exposé of the Evolution Industry. This book, by a secular journalist, shows how secular biologists are finding Darwinian theory so full of unresolved conceptual difficulties that they are conceding the field is in disarray and needs a new theoretical underpinning.

Or consider Francisco Ayala, whom Giberson and Collins cite glowingly. When Ayala is speaking candidly and not trying to shore up Darwinism against critics of evolution, he admits, "Unfortunately, there is a lot, lot, lot to be discovered still. To reconstruct evolutionary history, we have to know how the mechanisms operate in detail, and we have only the vaguest idea of how they operate at the genetic level, how genetic change relates to development and to function . . . [sic] I am implying that what would be discovered would be not only details, but some major principles" (from a 2002 interview with Larry Witham). Yet as far as Giberson and Collins are concerned, the mechanism of evolution is all sewn up and was sewn up ages ago by Darwin.

Over and over again they merely assert the truth of Darwinian theory. The only detailed item of evidence they consider in favor of Darwinian evolution is the defective GULO gene in humans and other primates. This gene, when intact, allows for the synthesis of vitamin C. Its common defectiveness in humans and other primates, according to them, argues for its common ancestry apart from design (common defectiveness not being something readily explained by common design). But this same defect is also found in guinea pigs, which, on evolutionary grounds, are so far removed from humans that this common defect could not be attributed to a common ancestor but rather must be explained as some sort of evolutionary convergence. But in that case, the defective GULO gene hardly becomes compelling evidence for our common ancestry with primates—humans might have started off with a functional GULO gene, which then subsequently became defective. (For more on this, see my book with Jonathan Wells titled The Design of Life.)

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.

4/27/2011 4:00:00 AM