The Silence of the Evolutionary Biologists
I am reviewing Jason Rosenhouse’s new book, The Failures of Mathematical Anti-Evolutionism (Cambridge University Press), serially. For the full series so far, go here.
The Darwinian community has been strikingly unsuccessful in showing how complex biological adaptations evolved, or even how they might have evolved, in terms of detailed step-by-step pathways between different structures performing different functions (pathways that must exist if Darwinian evolution holds). Jason Rosenhouse admits the problem when he says that Darwinians lack “direct evidence” of evolution and must instead depend on “circumstantial evidence.” (pp. 47–48) He elaborates: “As compelling as the circumstantial evidence for evolution is, it would be better to have direct experimental confirmation. Sadly, that is impossible. We have only the one run of evolution on this planet to study, and most of the really cool stuff happened long ago.” (p. 208) How very convenient.
Design theorists see the lack of direct evidence for Darwinian processes creating all that “cool stuff” — in the ancient past no less — as a problem for Darwinism. Moreover, they are unimpressed with the circumstantial evidence that convinces Darwinists that Darwin got it right. Rosenhouse, for instance, smugly informs his readers that “eye evolution is no longer considered to be especially mysterious.” (p. 54) It’s not that the human eye and the visual cortex with which it is integrated are even remotely well enough understood to underwrite a realistic model of how the human eye might have evolved. The details of eye evolution, if such details even exist, remain utterly mysterious.
A Crude Similarity Metric
Instead, Rosenhouse does the only thing that Darwinists can do when confronted with the eye: point out that eyes of many different complexities exist in nature, relate them according to some crude similarity metric (whether structurally or genetically), and then simply posit that gradual step-by-step evolutionary paths connecting them exist (perhaps by drawing arrows to connect similar eyes). Sure, Darwinists can produce endearing computer models of eye evolution (what two virtual objects can’t be made to evolve into each other on a computer?). And they can look for homologous genes and proteins among differing eyes (big surprise that similar structures may use similar proteins). But eyes have to be built in embryological development, and eyes evolving by Darwinian means need a step-by-step path to get from one to the other. No such details are ever forthcoming. Credulity is the sin of Darwinists.
Intelligent design’s scientific program can thus, at least in part, be viewed as an attempt to unmask Darwinist credulity. The task, accordingly, is to find complex biological systems that convincingly resist a gradual step-by-step evolution. Alternatively, it is to find systems that strongly implicate evolutionary discontinuity with respect to the Darwinian mechanism because their evolution can be seen to require multiple coordinated mutations that cannot be reduced to small mutational steps. Michael Behe’s irreducibly complex molecular machines, such as the bacterial flagellum, described in his 1996 book Darwin’s Black Box, provided a rich set of examples for such evolutionary discontinuity. By definition, a system is irreducibly complex if it has core components for which the removal of any of them causes it to lose its original function.
No Plausible Pathways
Interestingly, in the two and a half decades since Behe published that book, no convincing, or even plausible, detailed Darwinian pathways have been put forward to explain the evolution of these irreducibly complex systems. The silence of evolutionary biologists in laying out such pathways is complete. Which is not to say that they are silent on this topic. Darwinian biologists continue to proclaim that irreducibly complex biochemical systems like the bacterial flagellum have evolved and that intelligent design is wrong to regard them as designed. But such talk lacks scientific substance.
Next, “From Darwinists, a Shift in Tone on Nanomachines.”
Editor’s note: This review is cross-posted with permission of the author from BillDembski.com.