Behe Starts a Furor
“By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease function.”
Michael Behe, Chapter 2, Darwin’s Black Box
In 1996, Dr. Michael Behe provided in his book, Darwin’s Black Box (DBB), this simple definition for a simple, yet potentially powerful concept – irreducible complexity (IC). In the subsequent years, an academic war of words broke out which beckoned the question: why the furor? Surely the above definition alone couldn’t have started the maelstrom of criticisms that began soon after it was published?
Let me propose that much of the hullaballoo (did I really just write hullaballoo???) is due to Behe’s application of IC, which amounts to IC = evolution impossible. To clarify Behe’s argument, while it is impossible for a direct evolutionary pathway to produce an IC system, it is possible for indirect evolutionary pathways to do so. However, when he scanned the scientific literature, Behe noted that there was no paper describing the indirect routes in significant detail.
The Traditional Template Invoked
The concept IC as defined by Michael Behe is simple, brilliant and stands as a potential marker of design. To provide backup, Behe eloquently presented several cases of IC systems (cilia, flagellum, blood clotting, etc.). He also anticipated most of the criticisms directed towards his thesis and answered them fairly adequately. However, Behe became entangled within the Tradition Template of the debate the moment he presented a negative argument (IC = evolution impossible), and even though Behe attempts to make a positive argument for design in Chapters 8 through 11, the negative argument dominates DBB. In my opinion, this tactic has halted the concept of IC in its tracks before teleologists could take it for a proper test drive. By arguing an impossibility, Behe unwittingly assumed the “traditional role” of the dissenter.
Accordingly, Behe’s critics were more than willing to assume their “traditional role” to demonstrate that it is possible for DE to produce IC systems. Kenneth Miller, a biologist at Brown University, is generally credited with proposing the best argument against Behe’s application of IC: cooption* - the parts of an IC system were coopted from parts of other precursor systems. With cooption, Miller showed it was possible for evolutionary mechanisms to develop IC systems (Note I said possible, not plausible nor probable). Since Behe is arguing it is impossible for evolution to produce an IC system, all Miller had to do was show it was merely possible. Thus it would appear that the Traditional Template has given a seemingly crushing blow to IC**.
Hopping Down the Bunny Trail
Enter Mike Gene. In his book, The Design Matrix (DM), Gene takes IC for a test drive within the Explanatory Continuum.
First, Gene pointed out that cooption was “really the only evolutionary explanation that has the potential to explain the origin of an [IC] system.” Second, he recognised a flaw in the cooption argument:
“The most basic problem with the conventional use of [cooption] is its complete reliance on chance.”
Mike Gene, Chapter 8, The Design Matrix
Third, Gene made the cooption explanation plausible by incorporating his working front-loaded evolution*** (FLE) hypothesis.
Mike Gene then applied the brakes and headed back to the starting line. He granted that cooption is possible, thus avoids getting entangled in the Traditional. Gene then investigated what independent evidence is needed to progress it to plausible.
If cooption was to be a viable explanation, it must be gradual. Then Mike Gene pointed out that to construct an IC system through gradual cooption, “the previous existence of simpler precursors and multiplied functions” should be abundant. If these precursors are missing, then the IC system can be said to consist of “system-dependent parts”.
“A system-dependent part would be something that does not exist or function apart from the context of the machine.”
Mike Gene, Chapter 8, The Design Matrix
With this, Mike Gene laid the framework for one of four criteria in his Design Matrix (more on this in the next post). This, coupled with FLE, has advanced IC from Behe’s simple yet powerful concept to a possible marker of design. Thanks to Mike Gene, IC has new life.
Behe, M., Darwin’s Black Box: The Biochemical Challenge to Evolution, 2006
Gene, M., The Design Matrix: A Consilience of Clues, 2007
*Even if I am wrong and Miller did not originally come up with cooption, he is at least credited with being the “front-man” for the argument against IC = evolution impossible.
**There are many other critiques of Behe and IC; one of the more extensive (and honest) ones comes from Thornhill and Ussery, “A Classification of Possible Routs in Darwinian Evolution.” from Journal of Theoretical Biology in 2000. A summary of their findings can be found in Chapter 8 of The Design Matrix
*** “Front-loading is the investment of a significant amount of information at the initial stage of evolution (the first life forms) whereby this information shapes and constrains subsequent evolution through its dissipation. This is not to say that every aspect of evolution is pre-programmed and determined. It merely means that life was built to evolve with tendencies as a consequence of carefully chosen initial states in combination with the way evolution works.” Mike Gene, Chapter 7, The Design Matrix