The non-complexity of the mind

Creationists make an argument against the theory of evolution that goes by the name "irreducible complexity". I refer you to Wikipedia here for a detailed discussion of the argument. The idea is that that if a biological system is useless if any of its components is missing or modified then it could not have evolved - arisen from an accumulation of small changes. An every day example would be a mousetrap - it has no utility if any of its parts is missing, and so could not have evolved.

It turns out that in all cases suggested so far by the Creationists, the argument doesn't work. It doesn't work in the case of the mousetrap, either - somewhere out on the net is an example of how a good mouse-trap could arise from a series of small changes to a primitive mouse-trap. Biological systems have another trick up their sleeves as well. While the system may be useless at its current apparent function if a part is missing or changed, the modified system might very well have another use. Thus, e.g., a bacterial secretion system might evolve into a seemingly irreducibly complex flagellum - a means of locomotion that doesn't work if its parts are missing, but very plausibly works as a secretory mechanism.

As puzzles, the latter type of seemingly irreducible complex systems are the most interesting, their evolutionary pathway is not apparent from simple inspection. During the early part of its evolutionary history, the system was under a selection pressure different from that during the latter part. At some point the system "discovers" a new use, and now selection chooses improvements on the new function. Quite unlike, e.g, the idea of how the giraffe neck evolved. Supposedly, the giraffe neck is an accumulation of small changes, each small additional growth in the neck length giving its possesor an advantage in browsing tree-high foliage.

To come to the purpose of this post - it is that the evolutionary explanations of human intelligence and self-awareness to be more like the story of the giraffe neck than like the story of the bacterial flagellum. So, e.g., how did human mathematical ability arise? The standard story would be that mathematical ability is a manifestation of intelligence and from general primate intelligence to human intelligence there is a simple evolutionary pathway, small increments in intelligence almost always being advantageous selection-wise. So our minds have grown in some way analogous to the giraffe neck. Without something seemingly irreducibly complex intervening, our minds and behavior are explained by the conditions under which our predecessors evolved. This parody is the kind of explanation that bothers me. But maybe, the pathway to mathematical ability is more subtle, e.g., the functions associated with language were being selected for, and at some point those faculties "discovered" the new use of mathematics.

Anyway, enough said, I'm already sufficiently confused.