Behe's testimony at the Dover trial addresses the problems of this claim after he was given a stack of articles, that supposedly addressed Darwin's proposed pathway, by opposing cousel:
"The literature has no detailed rigorous explanations for how complex biochemical systems could arise by a random mutation and natural selection and these articles do not address that."
If Behe were only claiming that biology needed more detailed, rigorous explanations, then most biologists would agree and he would not be a darling of the ID movement. Behe's claim is that irreducibly complex systems are impossible to develop without intelligence, a claim refuted every time it is brought up.
To support Darwin's theoretical mechanism (random mutation and natural selection) one has to start at "a bit of wood", and show that a "bit of wood" arose by accident and how that "bit of wood" makes the animal "more fit" than without it.
We have dozens of mechanisms Darwin never knew about. Why should we limit ourselves to just the ones Darwin knew?
We don't need to start even with a "bit of wood". Any vaguely wood-like thing that is already serving some purpose will do.