A few quick reactions to Part III.
First, I'm not sure that the quote from Gould is really the right one
for your present purposes. You say (in a footnote) that you are not
dealing with homology here, but I think Gould is combining the issues.
As I read him, he is not simply arguing from imperfection to evolution
in this passage. A key point is a certain commonality - in the bone
structures in the limb of rat, bat, porpoise, and human, and in the
marsupiality of the large Australian mammals. It is not merely that
there are (as he sees it) imperfections, but that those imperfections
are in part a result of a shared, underlying structure which (on his
view) is accounted for by common descent. If that is right, then in
taking him to be going from mere imperfection to evolution, you have
misread him.
After the quote, you continue as follows:
The fundamental problem with this argument is that it requires a
super
-human level of understanding. If God were supposed to create each
creature
for "maximum survivability", then it is true that "imperfections" would
show
the truth of evolution. But what if God created each creature to serve
purposes other than mere survival? In that case, the only way to
determine
the suitability of each design would be to know all of the purposes for
which
it was created.
The dispute is, I take it, essentially this. Gould notes that
perfection could be handled by either evolution or direct design, that
given that fact, perfection would not discriminate between them, and
thus turns to imperfections (of a specified sort, if I read him right)
as a source of evolutionary evidences. Gould and you both agree that
certain sorts of imperfections would indeed show that evolution had
taken place. Gould thinks it utterly obvious that such imperfections do
exist, and takes them to constitute a powerful case for evolution. Your
response is that perfection of design (or, conversely, suboptimality)
can be defined only in terms of overall intended purposes, that we thus
cannot judge a design to be imperfect unless we have pretty secure
knowledge of the relevant overall purposes, and that in the present case
- involving God's overall intentions, on your view - we are not in any
position to say very much about most of the relevant details. Thus, we
cannot pronounce very authoritatively on the perfection/imperfection of
the designs in question, and consequently, for all we know, the designs
which might if taken in isolation appear to be suboptimal - rabbit
digestive tracts - might be utterly perfect as part of the larger,
global intentions. Thus, to use alleged imperfections against your
design position, Gould would have to know God's overall intentions in
some detail and would have to make the case that actual design was not
optimal with respect to those overall intentions and purposes. Since
that would take "super-human" understanding, Gould doesn't have much of
a case.
Your position here is certainly a *possible* one, but many would not
find it terribly plausible that the design of everything in nature in
the present - fallen - world is perfect for the ultimate overall purpose
of things. On the issue of sub-optimality, your opponents may well have
vbery defensible grounds here. And (as I've tried to make the case
previously) the mere possibility of an opposinig theory which can
accomodate all the relevant data (alleged imperfections, in this case -
Gould by claiming that they are imperfections and support evolution, you
by arguing that for all we know they may not be imperfections at all) is
perfectly consistent with one of the competiting theories having very
much the better time of it. Thus, merely establishing - if you have -
that it is for all we know *possible* that all overall designs are
optimal, does not automatically entail that Gould's case is very weak.
It is still *possible* to incorporate all observational data into a
Ptolemaic astronomical system - but that does not show that the case for
heliocentrism is in serious difficulty.
But why are you willing to grant - as you do in the pamphlet - that "If
God were supposed to create each creature for 'maximum survivability',
then it is true that 'imperfections' would show the truth of evolution"?
That does not seem true, at least in present form. Many creationists
claim that design imperfections need not be denied at all - they are
real, undeniable, and stem directly from effects of the fall. That the
initial creation designs were perfect need not be taken to imply that
there have been no disruptions since.
A bit later you say:
Some evolutionists will argue that effects of this kind are too
small
to be significant. How ironic that it was Darwin himself that proved
small
effects accumulated over a long period of time could have a significant
effect.
Darwin's last book was on the role of earthworms in turning the soil.
In
that book, he demonstrated that earthworms could bury large rocks if
given
enough time. In trying to argue that ecological effects are too small
to
be the reason for imperfections in certain designs, evolutionists are
trying
to have it both ways. They want to argue that small effects accumulated
over
sufficiently long periods of time can create the most spectacularly
complex
mechanisms known to man, but they also want to argue that small
ecological
effects accumulating over time cannot be the reason for the
imperfections of
design.
I think that Jim Foley is right here. I know of no evolutionist who
would take that line - or who would "want to" or "try to". In any case,
I don't think that you should make that sound like an actual or
expectable response unless you can provide cases.
You then continue:
A second reason for the rabbit's digestive system might be the
fact
that rabbits with a bad digestive system will have to eat more food than
rabbits with a good digestive system. More food at the same rate of
intake
means more time spent foraging for food. More time spent foraging for
food
means more time exposed to predators.
Some creationists are going to have a *very* difficult time with your
claim that (what you call) "bad" designs were deliberately produced in
order to make their carries more vulnerable to predation.
You continue:
If the rabbit's digestive system does have the effect of
increasing the
amount of time rabbits are exposed to predators, then evolutionists have
a
problem. How is it that rabbits have such a poor digestive system when
they
are one of the most preyed upon mammals on earth? If evolution by
natural
selection can produce efficient digestive systems, then it certainly
should
have done so in the case of the rabbit.
Here again, I think Jim Foley is right, but let me add a couple things.
There is no prima facie problem for evolution because (1) rabbits not
only have survived, but have positively flourished and nothing in
evolutionary theory suggests anything to the contrary or surprising
about that; (2) according to evolutionary theory, solutions to
evolutionary problems are typically closely linked to available survival
resources (with some suitable clauses) and relevant variations, etc.,
for increased rabbit digestive efficiency were never guaranteed to
arise; and (3) survival of rabbit species was the issue, and fecundity
is a perfectly respectable survival strategy for prey. Indeed, probably
any evolutionist would claim that fecundity *was* an important part of
the evolutionary response in this case. Tha fact that (given the
theory) evolution did not hit upon what seems to us to be the most
obvious solution - more efficient digestive systems - is no problem for
the theory at all.
One final note. You might want to check the technical literature and
terminology of rabbits. Rabbits might be described as ruminants who
utilize an external pathway, rather than the more common internal
pathway used by cows for their cuds, etc. In that case, "feces" is not
quite the right term.
Del