Ted Ashton writes, following Steve Dirickson:

>  > Why? Because those arrangements *aren't* random;
>  > they're extensions/outgrowths of a previous pattern, which was, in turn,
>  > based on an earlier, simpler pattern, etc. Sort of an evolutionary "if
>  > it ain't broke, don't fix it." Or, in this context, "if it worked fairly
>  > well, there's no need to explore completely unrelated patterns in the
>  > hope of finding something better--build on what you've got working now."
>
>  Ah, but then you run up against the "Irreducible complexity" that Wirt
>  mentioned--the situation where is *is* "broke" until you put together the
>  entire molecule.

It's important to understand that I wasn't endorsing the argument of
"irreducible complexity," I was merely explaining it. In fact, I don't agree
with the fundamental premise at all, that there exists such "irreducible
complexity."

Several people immediately wrote me privately yesterday and pointed out the
fallacy associated with this line of reasoning. One person wrote, "In
Talmudic logic there is a principle that says, "Because I have not seen it is
not a proof that it doesn't exist." This whole Intelligent Design idea falls
under this principle, i.e. since it is beyond my comprehension it can't be
real."

Stated another way, for this particular circumstance, "I can see no way that
all of these individual components could have come together in stages and
have worked as intermediate structures, without the whole of them being
there, therefore, because it is beyond my comprehension, ipso facto, there
must have been a Creator."

Deductive logic of this sort should always be viewed with enormous suspicion,
regardless of the context. The example -- and the example was real a century
ago -- that Carl Sagan made famous in the Cosmos series was the conclusion
that dinosaurs inhabit Venus. The reasoning goes this way:

     Dinosaurs on Venus ?

     Observation: Venus is completely covered with clouds. We can't see a
thing.

     Q: What are clouds made of ? A:Water.

     Q: Where do we find lots of that? A: In swamps.

     Q: What sorts of things live in a swampy environment? A: Dinosaurs

     Observation: We can't see a thing.

     Conclusion: Dinosaurs on Venus

This form of argument is called a syllogism, even though a classic syllogism
is composed of only three parts: a major premise, a minor premise, and a
conclusion. Quite often syllogisms are true, but they're wrong so often that
the word "syllogism" has also become a synomyn for a specious argument.

As to the specific nature of the "irreducible" argument and the functional
nature of the hemoglobin molecule that Michael Behe raised and Ted may be
talking about, there is a particularly well-written Creationist reply to this
specific "conundrum" by Terry Gray, Calvin College, Grand Rapids, MI, which
just happens to be Glenn Koster's alma mater. The reply is at:

     http://mcgraytx.calvin.edu/evolution/irred_compl.html

If you have the time, it's worth reading.

Nonetheless, it doesn't mean the general criticism of "irreducible
complexity" is not a valid attack on evolutionary theory. Behe's arguments
are not new. The notion, stated one way or another, has been a constant
companion of the evolutionary discussion since its very beginnings, and
Darwin himself raises the point in very many places in the "Origin of
Species," especially during that time when he was arguing only with himself
or answering his initial critics.

Indeed, Darwin devotes an entire chapter (Ch. 6) to the subject, a portion of
which I've quoted below. The "irreducible" argument -- or its close kin --
appears in the first sentence the following paragraph:

"It has been asked by the opponents of such views as I hold, how, for
instance, a land carnivorous animal could have been converted into one with
aquatic habits; for how could the animal in its transitional state have
subsisted? It would be easy to show that within the same group carnivorous
animals exist having every intermediate grade between truly aquatic and
strictly terrestrial habits; and as each exists by a struggle for life, it is
clear that each is well adapted in its habits to its place in nature. Look at
the Mustela vison [the American Mink] of North America, which has webbed feet
and which resembles an otter in its fur, short legs, and form of tail; during
summer this animal dives for and preys on fish, but during the long winter it
leaves the frozen waters, and preys like other polecats on mice and land
animals. If a different case had been taken, and it had been asked how an
insectivorous quadruped could possibly have been converted into a flying bat,
the question would have been far more difficult, and I could have given no
answer. Yet I think such difficulties have very little weight..."

The entire text can be read at:


http://www.literature.org/authors/darwin-charles/the-origin-of-species/chapter

-06.html

Wirt Atmar