Re: [asa] ID/Miracles/Design (Behe vs. Behe)

Preston Garrison wrote:
> This isn't the case. There are effectively an infinite number of
> possible mutations.
<snip>

Hi Preston,

I snipped this because of length, but let me say that I don't _strongly_ disagree with anything you wrote as you offer what is, I think, the "orthodox" analysis of the problem at hand. For reasons to be explained, however, I depart from "the orthodox analysis" and thus deny that the above excerpt from your post properly represents the situation. In consequence, I'll argue that my original point about chance and predictability of outcome stands undefeated.

Let me start by saying that I'm greatly influenced here by the work of Simon Conway Morris and his notion of convergence - the idea that despite our sense that there are, as you describe, an theoretical near-infinite number of evolutionary options available, it is demonstrably the case that, in practice, evolution has thrown up the same 'solution' to a particular 'need' on a repeated basis. To take one remarkable example, Conway Morris can elucidate at least six instances of independent evolution of the camera eye (Life's Solution, Cambridge, 2006, 151-158) - and that's just one of a wealth of actual examples upon which SCM draws.

One of his conclusions is that whilst there are, in theory, an immense number of possibilities, what we actually OBSERVE is a repeated tendency for outcomes to reoccur in a most curious manner.

This should - as Cameron has been arguing - really drive us to ask just how much "chance" exists in the process of evolution. If the camera eye has evolved on at least six occasions, then it implies that there is a whole lot more going on than SIMPLY the pointless activity of a Blind Watchmaker.

What strikes me, however, is that the only mechanisms we OBSERVE (there's that word again) for the modification of DNA are apparently random, then we are left with the difficult situation in which apparently random mutations of DNA lead to apparently common morphological characteristics.

Against that background, I can only surmise that the one false assumption in all of this (and it IS an assumption) is that there are, in effect, an infinite number of possibilities. In short, I disagree with the below;

<cite>
But when you consider all the possible insertions or deletions, inversions of large or small segments, rearrangements, transposition of the whole sequence or a fragment of any of the thousands of transposable elements to any position in the genome, sometimes carrying pieces of flanking DNA with them, insertion of virus DNA, occassional insertion of bits of other foreign DNA, etc., etc, etc, I would say that there is no doubt that nothing approaching saturation of "all possible mutations" occurs.
</cite>

I don't disagree that this is "in principle" correct - that if one was to perform a mathematical calculation regarding prior probabilities taking into account all potential point mutations, recombinations, etc, etc, then we would be dealing with enormously improbable events and that your closing assessment in the above is spot on.

HOWEVER, observation of what actually happens - that mutations are random, yet outcomes are strangely repeatable - suggests that, in practice, something truly remarkable is happening.

On that basis, I shrink from affirming that the concept of "random mutation and natural selection" is quite so inept a mechanism for producing evolutionary change as Cameron seems to have suggested - but that's only secondary to the main point.

The main point is this; if we restrict our comments to that which we have OBSERVED, then it is apparent that although we observe an apparently random process of DNA mutation as the "engine" of evolution, we also observe a repeated set of outcomes.

And as repeatability seems antithetical to chance, I think it follows that the inference "mutations occur randomly therefore outcomes are a matter of chance" is unnecessary and unjustified. We should rather be asserting "mutations occur randomly HOWEVER outcomes are largely predictable" - which assertion is grounded in a posteriori observations as to what actually happens in biological systems rather than a priori theorizing about what should be the case.

Blessings,
Murray.

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Received on Mon Apr 27 12:41:01 2009