Posted: Jun 24, 2010 12:07 am
CharlieM wrote:Behe:
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 functioning...Because the bacterial flagellum is necessarily composed of at least three parts - a paddle, a rotor and a motor - it is irreducibly complex.
CharlieM:
Note that Behe is not saying that it is impossible for an irreducibly complex system to be assembled by known naturalistic means. And he is not saying that if you take one or more parts away then the remainder will not have some function.
What he does say is that in considering the bacteria's flagellar motility system, if any one of the three parts mentioned above is removed then the system loses its motility function. Nothing that I have read here disproves this.
That's actually nearly exactly what he says. His own definition from page 39 of 'Darwin's Black Box' is as follows:
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 functioning. An irreducibly complex system cannot be produced directly (that is, by continuously improving the initial function, which continues to work by the same mechanism) by slight, successive modifications of a precursor system, because any precursor to an irreducibly complex system that is missing a part is by definition nonfunctional. An irreducibly complex biological system, if there is such a thing, would be a powerful challenge to Darwinian evolution. (p. 39)
