quote:
The neo-Darwinistic account is one of gradual change. The arguments about irreducible complexity arise because gradual change does not plausibly lead to very complex structures. The biology shows how complex structures can arise, but the gradualism of the neo-Darwinist model seems to argue against it.
Not so. First of all, the IC concept is flawed because it is based on taking away parts from already functioning systems, and making inferences about how it came about from that. This is backwards (and even Behe recognizes it, but has yet to fix the error). Secondly, there are several mechanisms by which IC systems can be generated via Darwinian means. One example is gene duplication and subfunctionalization. Another example is promiscuous protein functions, i.e., additional functions a protein may have that are not tied to the primary function (and scaffold) structure of the protein. Mutations can occur to these without detrimental effects because the primary function of the protein isn't affected. Consider an IC hormone/receptor relationship. Traditional IC theory considers this irreducibly complex because one cannot evolve without simultaneous change in the other. Of course, if the functionality in both hormone and receptor proteins start out as promiscuous functions of other proteins, they can coevolve without any detrimental effects of mutations to either, since the primary functions of both original proteins isn't affected. Eventually, gene duplication and specialization could result in two unique proteins with a tight relationship that would appear to be 'unevolvable'.
A
Surely there's more than one "IC is the death of evolution" advocate around here.
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