OU Biochemist Phillip Klebba on the Bacterial Flagellum
|December 3, 2007||Posted by William Dembski under Intelligent Design, Darwinism|
My to-do list for some time has included addressing University of Oklahoma biochemist Phillip Klebba’s written response to my September 17, 2007 OU lecture at Meacham Auditorium. Klebba, during the Q&A, asserted that biologists know full well how the bacterial flagellum arose without the need for intelligent design. He then proceeded to describe a four-stage evolutionary process that went from a pilum to the type-three secretory system to an ATP-type motor to the full flagellum. I told him during the Q&A that he was bluffing and that his account of flagellar evolution did not provide the specificity needed to confirm its plausibility. He then lectured me on the fact that I’m not a biologist and thus was not in a position to make such a pronouncement. But the fact is that one does not have to be a biologist to assess Klebba’s claims. Rather, one needs some elementary facility with logic to see whether his claims stack up.
Fortunately, Klebba wrote up his proposal on flagellar evolution in an essay for the OU student newspaper (the essay appeared September 20, 2007 here). I urge UD readers to look at it carefully for it betrays the bankruptcy of evolutionary theorizing when it comes to explaining the emergence of molecular machines. Contrary to molecular and cell biologists such as James Shapiro and Franklin Harold, who regard current evolutionary explanations of molecular machines as spectacularly unsuccessful, Klebba proclaims that the problem is solved:
The evolutionary relationships that led to the bacterial flagellar motor — the poster of irreducible complexity for proponents of intelligent design — are now well-known among scientists studying the biochemistry of bacterial cell envelopes. In brief, the flagellar assembly, which propels bacteria through fluid environments, consists of a long, hollow polymeric filament, a basal body that holds the filament in the cell membrane system, and a molecular motor complex containing a stator and rotor that turn the filament around and around when it is energized.
I’m afraid that after all these years in the ID business, I’m still not entirely used to the brazenness of evolutionary theorists in proclaiming that its unsolved problems are solved. Klebba continues:
In reality, a number of precursors to the complete flagellar assembly are known. They provide the stepwise development of novel functions, and when juxtaposed together, lead to a selectable trait. The emergence of the flagellar motility system involves a progression from pili to type-III secretory systems, that acquires the proton-motive, force-driven rotational capability of the ATP synthase motor (a primary source of energy generation) and sensory and regulatory systems that determine the direction and the duration of cell propagation. Each individual system alone has survival benefits for the cell. When combined one-by-one, they provide a stepwise path to the development of a new advantageous trait: the ability to swim toward something desirable, e.g., high concentrations of sugars — and away from something noxious, e.g., high concentrations of acid. This adaptive evolutionary progression is simple and logical, but unfortunately, is not understood by Dembski and his colleagues.
Actually, my colleagues and I understand such explanations all too well. In fact, why stop at four evolutionary stages in explaining the flagellum? Nick Matzke some years back had six (see my reply to Matzke’s proposal here). Klebba, Matzke, and others seem not to understand that arguments from imagination in which one posits a few putative evolutionary precursors do not constitute a detailed testable model for how the flagellum arose. Take Klebba’s transition from a pilum to a type-three secretory system. Precisely which pilum and which type-three secretory system does he have in mind? How exactly did a pilum shed its hair-like filament in becoming a type-three secretory system (last I looked, type-three secretory systems are microsyringes that do not have hair-like filaments)? What new genes need to be added to form a type-three secretory system from a pilum? What old genes need to be lost to form a type-three secretory system from a pilum? In the evolution from the pilum to the type-three secretory system, how many intermediate systems whose functions were neither that of a pilum nor that of a type-three secretory system were there? Klebba and his colleagues never answer such questions.
To me it is mindboggling that evolutionary theorists continue to get away with this sort of shoddy reasoning (no, wait, I wrote an essay on “Evolutionary Logic” some years ago — I do understand!). Systems like the bacterial flagellum are engineered systems. An engineer explaining the technological evolution of such a system would have to exhibit the actual systems in its evolution and show the precise changes required to go from one system to the next. Evolutionary dreamers like Klebba, on the other hand, need merely cite some general categories of systems and then proclaim that “evolution” (used as a conjuring word like “abracadabra”) can tie them all together.
Toward the close of his essay, Klebba remarks: “As a researcher who understands the biochemistry that was the main subject of the lecture, I was surprised to find the discussion much less substantive than I anticipated.” The lack of substance is entirely on Klebba’s part. Indeed, simply citing his own credentials and then offering a handwaving account of how the flagellum arose does not resolve an outstanding open problem confronting evolutionary theory, namely, how Darwinian processes can actually clear the brick wall that they constantly seem to run into when trying to account for molecular machines such as the flagellum.
I ran Klebba’s essay by a molecular biologist colleague who works professionally on the flagellum (not Behe). Here’s what s/he wrote back:
I imagine Phil is citing the Matzke/Pallen article or Milt Saier’s recent article. What I find interesting is that both admit we have no evolutionary scheme to account for the flagella; instead they merely offer a “plausible” account. That being in print, it is now taken for gospel. Both Pallen and Saier have changed they position radically in recent publications. In 2005, Pallen wrote a bioinformatics paper asking how good is the E. coli/Salmonella flagella paradigm across the phylogenetic tree. Amazingly, it holds up well by their blast comparisons. In 2006, the situation has changed where they state now that to use E.coli/Salmonella for a paradigm, as used by ID proponents, doesn’t make sense — there is no true flagellum. Saier likewise argued in 2005 that based on bioinformatics, the flagellum must have arisen before the Type 3 system. Now he conveniently asserts that both are the product of some hypothetical ancestral protein secretion system. . . . [O]ne might ask where did Phil Klebba get his information (or more precisely his “revelation”) that the evolution of the flagellum has been worked out??? When no one knows. From Matzke? Someone with a Master’s degree in Geography? Reminds me of the old adage applied to fundamentalist preachers — “Argument weak, shout here!”