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The Big Bad Wolf, Theism and the Foundations of Intelligent Design - Page 7

Irreducible Complexity

"We believe in evolution because the evidence supports it, and we would abandon it overnight if new evidence arose to disprove it." - Richard Dawkins 69

In discussing and dismissing the argument for intelligent design from irreducible complexity, Dawkins quixotically dissects examples from a book with no named author, published by the Jehovah Witness' Watchtower Bible and Tract Society, entitled Life - How Did It Get Here? Dawkins easily blows away the argument that since the insect-trapping and purportedly "irreducibly complex" plant Aristolochia trilobata (Dutchman's Pipe) could not have happened "by chance" it therefore must have been intelligently designed. Of course, as Dawkins points out: "Design is not the only alternative to chance. Natural selection is a better alternative." 70 But such straw man bating is simply a red herring that avoids serious engagement with the far more sophisticated arguments of Intelligent Design theorists proper.

When Dawkins finally gets around to defining irreducible complexity, he summarizes the concept in his own words as follows: "A functioning unit is said to be irreducibly complex if the removal of one of its parts causes the whole to cease functioning." 71 This unreferenced definition is an oversimplification of irreducible complexity as defined by the originator of the phrase, biochemist Michael J. Behe. Behe's most notable presentation of irreducible complexity is Darwin's Black Box: the Biochemical Challenge to Evolution (1996/2006), where he defined irreducible complexity as follows: "By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning." 72

To propose that a system (such as the flagellum) is irreducibly complex (IC) is not to argue for design by definition, but to lay the foundation for an inference to design from uniform experience. Behe observes that if a system is IC then it is impossible to evolve that system via a direct evolutionary pathway: "An irreducibly complex system cannot be produced directly... by slight, successive modifications of a precursor system, because any precursor to an irreducibly complex system that is missing a part is by definition non-functional." 73 Behe admits that: "although irreducible complexity does rule out direct routes, it does not automatically rule out indirect ones." 74 However, he argues that the more complex the IC system in question is (i.e. the more necessary parts it contains): "the more unlikely the indirect routes become." 75 Behe does not move directly from the unlikelihood of an evolutionary explanation of an IC system to the hypothesis of intelligent design. Rather, he notes that:

irreducibly complex systems such as mousetraps and flagella serve both as negative arguments against gradualistic explanations like Darwin's and as positive arguments for design. The negative argument is that such interactive systems resist explanation by the tiny steps that a Darwinian path would be expected to take [because direct routes are impossible and indirect routes unlikely]. The positive argument is that their parts appear arranged to serve a purpose, which is exactly how we detect design. 76

Hence Behe defends his argument against the charge that it is an argument "from present ignorance":

there is a structural reason - irreducible complexity - for thinking that Darwinian explanations are unlikely to succeed. Furthermore... irreducible complexity is a hallmark of intelligent design... Truncating my case for intelligent design and then saying I commit the fallacy of argumentum ad ignorantium is not, in my opinion, fair play. 77

Dawkins fleetingly mentions Behe, but only to label him (inaccurately) as "the creationist Michael Behe... credited (if credited is the word) with moving creationism into a new area of biology: biochemistry and cell biology..." 78 Behe, the primary source of the argument Dawkins is opposing, apparently does not merit a single quotation by Dawkins (he'd rather dissect a popular work by an anonymous creationist), even when he critiques Behe's most famous example: the bacterial flagellum. (Dawkins writes that the flagellum is "happily described as a tiny outboard motor - and unusually for a biological mechanism - it is a spectacularly inefficient one." 79 However, the flagellum has an energy conversion efficiency "close to 100%" 80 and Japanese scientists have studied it with the aim of producing energy saving nanotechnology 81 ; so it seems that Dawkins has his facts wrong.)

Dawkins dismisses "The absurd notion that such complexity could spontaneously self-assemble" but asserts that "Evolution... goes around the back of [Mount Improbable] and creeps up the gentle slope to the summit: easy!" 82 Anyone familiar with the contemporary ID debate should know that such a response is far too "easy"; if a system is IC then it cannot evolve "directly" round the back of Mount Improbable and is unlikely to evolve "indirectly" up the back of Mount Improbable. Dawkins deduces the existence of a statistically plausible, indirect graded ramp up the back of Mount Improbable from the naturalistic assumption that evolution must be true; but as Danish philosopher Jokob Wolf observes:

An explanation of the evolution of an organism is scientifically adequate only if it is able to account for all the incremental steps required for the building of the system. These steps must be so small that their probability can be calculated. Which means that you should actually be able to quantify the probability of every small step, and so prove that it is reasonably probable that it constitutes a step on the evolutionary ladder. You also have to be able to prove that each step presents an advantage to the organism. Currently, there exist no Darwinian explanations of e.g. the bacterial flagellum which satisfy these criteria... Darwinian accounts purporting to account for the emergence of very complex systems are primarily expressions of the hope that the evolution of these systems is explainable by appeal to the Darwinian mechanism. They are wishful speculations. 83


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