The key evidence for part (b) of the ID belief is that life is simply too complex to have developed via evolutionary processes. The idea of "irreducible complexity" falls under this part with Michael Behe being a leading spokesperson for this view. In Darwin's Black Box, Behe says that irreducible complexity is "a 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." (Behe quoted in Coyne, p. 29)
Michael Behe (b. 1952)
Bacterial flagella arrangements
For example, the removal of one part of a standard 5-component mousetrap would render the mousetrap useless. Behe says that the various parts of biochemical systems such as the blood-clotting process or bacterial flagellum (the whip-like "tails" of bacteria they use to move around) could not have assembled together piece by piece to make the complex systems via natural selection. These complex systems would have to have arisen "as an integrated unit, in one fell swoop". In a recent article in the New Republic Jerry Coyne says that biologists have known for decades that natural selection "can indeed produce systems that, over time, become integrated to the point where they appear to be irreducibly complex. But these features do not evolve by the sequential addition of parts to a feature that becomes functional only at the end. They evolve by adding, via natural selection, more and more parts into an originally rudimentary but functional system, with these parts sometimes co-opted from other structures." (Coyne p. 30) So for the mousetrap analogy, three of the parts can be used as a tie clip or paper clip, two of the parts can be used as a key chain, one part can be a fishhook, another as a paperweight, etc. The various parts had other functional uses. For each of the systems Behe has described in his various writings, biologists have shown how those systems could have arisen via evolution with natural selection.
Behe appeals to ignorance of a natural mechanism to argue for a proof of a God-action. As I mentioned above, this is not good scientific practice because appealing to a supernatural cause is a cop-out or a dead-end to deepening our understanding of the natural world. There would be no reason to continue looking for a natural explanation. Also, this argument of Behe's is just like the "God of the gaps" argument that theologians have rejected. For theologians, the God in the gaps argument reduces God to irrelevance as more and more gaps are filled in.
|Assumptions of Science||Theory + attributes||Methodological Materialism|
|Evolution via natural selection||Imago Dei||ID beliefs: God-action detection|
|Irreducible Complexity||Specified Complexity|