Del Ratzsch writes:
>I don't think that that is quite right. In a stable situation where the
>only variations are in the direction of reduced fitness, all the above
>may be true, but natural selection will act only as the "executioner of
>the unfit", and there will be no evolutionary movement - not even
>microevolution - at all. In fact, Darwin was stymied by that fact for
>some time.
It seems difficult to believe that anyone would advance this as an argument
for evolution.
He continues:
>In any case, the above four do not "mathematically" entail
>microevolution.
Take it up with Mark Ridley. The reference is his textbook **Evolution** which
got rave reviews from many high profile Darwinists.
Del continues:
>I don't think that that's quite true either. Take the scenario I just
>sketched, and allow only suitably harmful mutations. The original four
>conditions will be true, God will not have done any of the above eight
>things, and there will be no microevolution.
Again, difficult to believe that anyone would advance this as an argument
for evolution.
>That's a bit oversimple. Theory discrimination and selection still goes
>on even when the theories involved are empirically equivalent. For
>instance, the Copernican and Tychonic systems were empirically
>equivalent astronomically - and easily proven to be so - but the
>Copernican theory won that competition hands down on the basis of a
>number of philosophical considerations thought to be scientifically
>important - elegance, "simplicity", and perhaps some other harder to
>define considerations.
Remember that the purpose here is to outline the case for and against evolution
in simple terms in a SHORT pamphlet. A certain amount of simplification is
required. By the way, if any theory is to win out on the basis of
"simplicity and elegance" it certainly WONT be the modern theory of evolution.
(And of present relevance, some versions of
>progressive creation *may* be empirically indistinguishable from
>evolutionary theories - but that hasn't seemed to stop anyone from
>choosing sides here.)
I cannot prevent people from being irrational, I can only spell out
a rational approach to deciding between the idea of intelligent design
and the idea of emergent evolution.
Del continues:
>Is that true? When conditions are _reversed_ they may disappear
>(peppered moth, finch beak size, etc.), although I've never seen any
>discussion of how typical that is. But they disappear when conditions
>merely change? Are there data supporting that claim?
This claim is equivalent to saying that deviation from the species norm
is harmful to the health of individuals. Evidence favoring this claim
includes studies done on the peppered moth, beak size of birds that varies
during dry and wet seasons and the fact that dogs released back into the
wild tend to move back to the species norm. To be honest, I have not
referenced this claim as rigorously as I should have and the word "usually"
may therefore not be appropriate. I will research this claim more thoroughly.
(If anyone has any helpful suggestions as to how I might go about this, I
would be grateful.)
Del continues:
>What that comes to, I take it, is that if some bit of data is not
>inconsistent with a theory and is indeed expectable on that theory, then
>those data cannot constitute strong evidence for some alternative
>competing theory. That claim does have some plausibility, but I think
>that we have to be careful here. Given the general underdetermination
>of theory by data, every theory always has possible competitors, each of
>which is consistent with all the data in question and, indeed, from each
>of which that body of data is derivable. One doesn't want to adopt a
>principle which, in the light of that underdetermination, would imply
>that no data ever constitutes strong evidence for any theory. The
>relationship of data to theory and the whole area of confirmation are
>pretty tangled, and I am a little nervous that the principle underlying
>the "conclusion" section of the pamphlet may not do full justice to some
>of those tangles.
This concern is alleviated by the fact that I really don't care which version
of intelligent design theory a person favors over the modern theory of
evolution. All I care is that they understand that some intelligent design
theories are competitive with modern evolutionary theory. (Actually I would
say superior to, but that is not the claim I am making in the pamphlet.) Given
the abuse that the concept of "testability" has taken at the hands of
evolutionists, I am not overly concerned with criticisms concerning the
underdetermination of an intelligent design theory.
Del also asks for references regarding part II of my pamphlet. Understand
that my purpose was not only to address the concerns of the evolutionists
who are members of the scientific community, but also evolutionists one
meets on the street or at the bus stop. The reference for this particular
argument, if you must know, is Rob Bielby.
In Christ
robert van de water
associate researcher
UCLA