Creationist Critique #2: There is a problem with irreducible complexity

So I continue to run through the anti-evolutionary arguments.    I’m just staying focused on the critiques which claim to be scientifically based.   I can understand why people would dispute NeoDarwinian evolution on theological grounds.  (Though I don’t agree with them.) I’m focused on the scientific arguments because I believe these are mostly wrong-headed, resulting from misunderstandings.

This particularly critique of evolution goes like this:

Natural selection is based on the idea that every little tiny baby step along the way confers some advantage.  It can not delay gratification.  If it takes 1000 generations to achieve a given structure each step toward that structure must be better than the step before.

Opponents of evolution observe that there appears to be no benefit from half an eye.  They state that each individual cell is much more complex than an eye, and that no intermediate steps are apparent that get us part way toward the development of many organelles.

It is true that each tiny little variation between generations must be a benefit in order for structures to grow increasingly complex.  But I don’t see that the case has yet been made that organisms are irreducibly complex for the following reasons:

A) This argument usually picks on three structures: the eye, the cell, and the wing.  It is interesting to note that the first two don’t leave fossils.  The eye is soft tissue and the cell is too small.  It would be basically impossible for biologists to decisevely answer these questions based on the fact that we have no evidence in either direction. 

The book Darwin’s Black Box, huge in the 1980’s, focused on the cilia and how half a cillia provides no apparent advantage.  Recent developments in microbiology have helped us understand that cells used organelles quite similar to cillia for other functions entirely.  These proto-cillia were around, and evolution made use of them in whole new ways.

As for eyes and wings, it’s only half-true to state that half an eye or half a wing confers no advantage.  It is quite true that we don’t see ancestors of modern human eyes or modern bird wings lurking about the animal kingdom.  But there are organisms with quite different light-detecting mechanisms that have little resolution.  The ability to see light and darkness does convey advantage.  It’s not hard to imagine our eyes’ ancestors developing with similar ancestors, that initially allow us to tell day from night, for example.  Similarly, there are animals such as “flying” squirells that appear to be evolving toward increasingly long leaps.  Contemporary wings might have evolved as a result of the increased advantage of increasingly long leaps.

B) As mentioned for the cillia, an advantage doesn’t need to mantain it’s original purpose or function.  Spiders began simply excreting waste.  Slowly, this took on a new function and became an elaborate fly trap.  (Sorry, I guess that example is kind-of gross.)


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