Re: Behe and IC

In message <q1enb21vv7r19fbcljba9jne2olsra26ge@xxxxxxx>, *** <remdickhm@xxxxxxxxxxxxx> writes
Someone complained that Behe did not provide enough details to
evaluate Irreducible Complexity. He provided a lot of detail about
the "Cilia" in chapter 3 of Darwin's Black Box, starting with a sub
chapter entitled: "The Cilium." He discusses parts that make up the
cell, the chemistry and how they work together including chemical
components.

Now, it is way beyond my abilities to judge whether Behe is pulling
the wool over my eyes, but to my limited knowledge, he has provided a
lot of detail including a diagram and the tools used to get the
information.

***

There is a degree of equivocation in the meaning of irreducible complexity - between, on the one hand, possession of the characteristic that when one part is removed the system no longer functions, and on the other hand, unevolvability.

(I don't know whether Behe confuses these two senses, not having read his work, but the confusion is widespread in discussion of his work.)

It is hard to identify an irrefutability irreducibly complex system - partly because of the absence of an objective scheme for dividing systems into parts. However, the bottom line is that the exixtence of irreducibly complex systems is not only not a challenge to the theory of evolution, but is predicted by the theory of evolution. (I don't recall the details, but, as I recall it was predicted in the first half of the last century.) There are at least three classes of paths by which irreducibly complex systems can evolve.

1) scaffolding paths - the system evolved from a larger, but not irreducibly complex system. A classic, non-biological, example is the arch.

2) exaptation paths - the system evolved from a simpler system which filled a different role.

3) coadaptation paths - for example a protein that performs a function undergoes a mutation that causes it to bind a cofactor that results in it performing that function more efficiently. Once this has happened selection will act to improve the protein in the presence of the cofactor. There is no pressure to retain function in the absence of the cofactor, and therefore it may be lost. This results in an irreducibly complex system - the protein and cofactor.
--
alias Ernest Major


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