Re: [asa] Behe Responds To Ken Miller - Edge of Evolution

David C. said:* Co-option falsifies IC (irreducible complexity) because it
provides a
way to assemble the complex system step by step.*

Not so. In itself, cooption shows only that some components of a putatively
IC system could possibly have been borrowed from some other system. It does
not, in itself, show how the entire system could have been assembled
step-by-step such that there is some utility in the system at each step.

The posibility of cooption might suggest a system really isn't IC, but it
would have to be the case not only that there are coopt-able parts that
would "fit" the system, but also that the putatively coopted parts were
available for cooption and that they could have been assembled all at once
into the IC system. This requires both some kind of proximity as well as
some possibility of self organization of the system. It isn't enough to
suggest that there is a small piece of metal on Mars that could be used as
the catch bar in a mouse trap; you have to show that there is a small piece
of metal in proximity to the other components and that there is a mechanism
for spontaneous and complete self-assembly of the proximate parts into a
system; or that there are intermediate systems to which proximately
available parts could gradually be added, each of which intermediate systems
has some utility.

So, to suggest that cooption in itself falsifies IC, it seems to me, is
really just hand-waiving. Either that, or it really is a fundamental
misunderstanding of what IC is supposed to mean.

Now, Ken Miller cites a bunch a papers that supposedly show a pathway in
which the bacterial flagellum could have been assembled through gradual
cooption of parts into the present motor system. But this is where it gets
frustrating for someone like me: when you dig into the papers he cites,
they don't seem to support anything like such a grandiose claim. In some
instances, it seems more like "well, there's a little piece of metal on Mars
that could serve as the catch on a mousetrap," rather than any kind of
meaningfully plausible scenario. (Either that, or my incompetence with the
literature makes me -- and Angus Menuge, from whose "Agents Under Fire" much
of this rebuttal comes from -- miss something.)

I do think it's fair to say that the possibility of cooption suggests that
something that *seems* to be IC *might* be derivable through natural
selection after all, which I would agree should make us chary of grand
claims for the concept of IC -- certainly it should make us reject any claim
that the concept of IC *must be* a show-stopper. However, it equally
overstates the case, IMHO, to claim that the concept of cooption
conclusively settles the matter against IC as a possible roadblock for
natural selection.

On 7/13/07, David Campbell <pleuronaia@gmail.com> wrote:
>
> There are a lot of other studies on mutation frequencies. Selecting a
> single one does not give much credibility. Another problem is that
> Behe is assuming a specific target for the mutation in calculating
> probability, whereas in reality evolution proceeds with anything
> functional enough to survive and reproduce. Thus, Behe has
> demonstrated that humans are not very likely to evolve resistance to
> chloroquine, not that humans are not likely to change in some fashion.
> Drug resistance is likely to be somewhat atypical in this regard, as
> drugs typically target a very specific cellular mechanism in the
> target organism and require a specific response. In contrast, global
> warming might be compensated for by metabolic, behavioral, or
> geographic shifts (and maybe more).
>
> > John T -- I don't think you're getting at the same thing Behe is saying
> > here. Behe says an IC system is one in which the removal of one part
> will
> > collapse the system. Behe says Miller represents that an IC system is
> one
> > in which the parts of the system can't be used for any other
> purpose. Thus,
> > Miller claims to have falsified IC by showing that the parts of a
> putatively
> > IC system could be used for another purpose, in a different
> system. This is
> > the "cooption" argument -- the IC system could arise through the
> cooption of
> > its parts from other systems. Behe says that is not a falsification of
> IC
> > at all; whether the parts can have functions in other systems doesn't
> > matter; one still has to show how the incomplete IC system would
> function > as it coopts parts, or how the IC system could spontaneously
> coopt all the
> > parts at once into a working system. Angus Menuge makes some
> > interesting arguments about this in his book "Agents Under Fire."
>
> Co-option falsifies IC (irreducible complexity) because it provides a
> way to assemble the complex system step by step. Behe's reasoning is
> wrong because he assumes that the system must provide the final
> function in order to exist. Co-option tells how the incomplete IC
> functions-it does something else.
>
> There's an underlying issue of how to define IC. One definition is a
> system that requires all its parts to function and will not perform
> that function unless all the parts are there. However, such a system
> can readily form without intelligent intervention. It may build up
> from existing pieces, with the novel function of the system appearing
> once all the parts are in place. Or it may be the case that the
> system could be reduced with a little tweaking (e.g., one part could
> ), or has a very similar function when reduced a bit, etc. In fact,
> this definition is so broad that a large molecule would qualify.
> E.g., sepiolite has several useful physical properties that depend on
> the exact configuration of numerous atoms in a repeating structure.
> Replace one atom with another element, or rearrange them, and the
> properties are lost. It forms by weathering of other minerals.
> Popular definitions (e.g., the one in the proposed Ohio ID-inspired
> "science standards") are often even broader. As for specified
> complexity, the definitions have a definite post hoc feel to me, i.e.
> they sound as though Behe, Dembski, et al. are trying to come up with
> a definition that fits complex biochemical systems and makes them
> sound hard to evolve, rather than examining human-designed objects and
> looking for what distinguishes them from "natural" objects.
>
> Another definition somewhat acknowledges this difficulty by adding
> caveats about not being readily formed or explained according to
> physical laws. However, this falls into the trap of affirming the
> consequent, as well as being impossible to delineate securely-"not yet
> explained" is the god of the gap again, and "has a good physical
> explanation" has a significant subjective component, both in how good
> is good and in what level of knowledge about the system ought to yield
> explanations of its origin. All the ID focus on complex biochemical
> systems is in the long run ill-advised because we still know so little
> about them. Claiming that something is inexplicable because it is as
> yet not fully explained is thus very premature.
>
> --
> Dr. David Campbell
> 425 Scientific Collections
> University of Alabama
> "I think of my happy condition, surrounded by acres of clams"
>
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Received on Fri Jul 13 15:55:11 2007