I've stated in an earlier post that I believe we live in an optimal
universe. I do not believe that I could design a better universe. I
believe, with Richard Owen, that it is necessary to have minor
imperfections to optimize the whole. The difference is that the whole
for me is the universe with self-conscious creatures with apparently
genuine free will.
This view did not emerge simply from my evolutionary perspective,
but from biblical and other biological considerations. Consider
embryonic development. There are passages which indicate that God
forms the foetus in the mothers womb. My daughter, Rachel, was born
without a functioning thyroid. Do I believe that my daughter could
have been formed better? Frankly, yes. We would have liked her to be
born with a thyroid. Before anyone accuses me of playing God, let me
quickly add that I believe that God knows what He is doing. There
are, of course, other considerations besides optimizing the
individual. Faithfully sustaining natural laws and giving the
universe adequate autonomy come to mind - to name just a few.
I do not expect Paul to agree with me, of course. However, I don't
wish to be automatically thrown into the same camp as secular
humanists.
PN:
> Indeed, image quality is *known* to be affected by RPE disfunction
> (Zinn and Marmor 1979). I know of no defects associated with
> photoreceptor orientation, other than the completely hypothetical
> ones spun from gossamer by Goldsmith (1990). I read Goldsmith
> carefully, when that paper was first published, and he never even
> attempts to demonstrate that the orientation is suboptimal. He
> merely asserts it.
Here is a suggested better design. Reverse the orientation. Keep a
single layer of vascular tissue for maintainance of the
photoreceptors. You will still have a blind spot - now vascular
rather than nerve. The advantage is a barrier to the light of a
single layer rather than the four-layer (if my memory serves me
correctly) of the retinal processor.
> The problem with comparing the vertebrate to the cephalopod
> system is the degrees of freedom involved. If one makes a list of
> the features peculiar to each, it becomes immediately apparent that
> one cannot isolate photoreceptor orientation as the only consideration
> relevant to optimality. But that's just what Goldsmith does.
Agreed.
>
>
> On the issue of the recurrent laryngeal nerve, Mike writes:
>
> >There is no KNOWN functional reason for a long pathway. Could there
> >be a functional reason for the long pathway? Sure. Anything is
> >possible - especially in biology. All we can do is to discuss the
> >available evidence. You have to provide evidence of a function
> >otherwise you could be accused of doing the armchair theorizing of
> >which you accuse others.
>
> The burden of
> proof rests with you, Mike. Show us that it's suboptimal. Don't
> ASSERT it -- give us some *evidence*.
The evolutionist is one up on you Paul. This nerve does a loop and
cries out for an explanation. A functional one cannot be given while
the historical one below can. At least he or she can provide an
explanation. You cannot. Sub-optimality? It does not appear to me to
be good economics to build a detour without any apparent function
(but I've already intimated this).
>
> The following doesn't qualify:
>
> >Biologists do have an explanation for the recurrent nerve.
> >It was originally the 4th branch of the vagus nerve in the fish. Here
> >the route is direct. The nerve followed the same route through the
> >higher vertebrates but as the neck became longer the detour came to
> >look increasingly absurd.
>
Why not?
> I'd be interested in this explanation if Mike could explain some
> of the macroevolutionary transitions involved (e.g., the invention,
> de novo, of the amniotic egg).
This sounds like changing the subject.
> But it's a tad silly to justify evolution
> on the grounds of "you know, if I were the Creator, I'd make sure the
> recurrent laryngeal nerve was shorter. Because God, as played by me,
> wouldn't have done it that way. Thus the vertebrates must have
> evolved."
Anyone can be made to look silly by stating isolated bits of their
argument. My argument was not merely that the recurrent loop has no
known function, but that it appears to trace the path of lower
vertebrates. I wouldn't call this a knock-down argument for
evolution, but should be taken together with other lines of evidence.
>
> Mike's other examples of suboptimality are also non-starters. The famous
> "chick teeth" experiment (Kollar and Fisher 1980) was never cleanly
> replicated, and doubts have been raised about the methods employed
> (Marshall, Raff, and Raff 1994:12286-87; Raff 1996: 393).
Thanks. I won't use this example again without checking it further.
>That some
> cetaceans develop and resorb teeth in utero may be counterintuitive,
> but I expect the structures play a developmental (inductive) role,
This is possible, but where's the *evidence.* There is another
possibility of course. These transitory teeth were inherited from a
toothed ancestor. Do you exclude this possibility. If so why?
Mike
________________________________________________
Mike L Anderson, PhD
Director: Christian Academic Network
mla@iafrica.com
78 Balfour Road, Rondebosch, 7700