On Wed, 11 Dec 1996 19:03:31 -0600, Steve Clark wrote:
[...]
>SC>...Behe's model, however, does not seem to account for the
>possibility that a mousetrap could evolve from something that
>originally did not function as a mouse trap, which seems more
>congruent with a macroevolution scenario.
>SJ>Actually Mike *does* deal with this: "Even if a system is
>irreducibly complex (and thus cannot have been produced directly),
>however, one can not definitively rule out the possibility of an
>indirect, circuitous route. As the complexity of an interacting
>system increases, though, the likelihood of such an indirect route
>drops precipitously.
>SC>What does this mean? Most people would recognize that complexity
>provides a daunting challenge to evolution. Darwin recognized this
>in the eye. But this is a problem for ANY model that attempts to
>explain the origin of complex structures. Besides, the "indirect"
>route isn't a necessary alternative to the gradual fine tuning of
>some functionally irreducible structure that Behe seems to favor.
>If evolutionary changes are not constrained by the requirement to
>gradually make a better mousetrap, then large changes in
>function--to say a catapult, can be arise from relatively small
>changes in structure. This is not "circuitous." In fact,
>significant changes could arise quickly rather than gradually if the
>constraint on function is minimized.
This is what Behe would no doubt call a "Calvin and Hobbes"
story. Try it on the blood-clotting cascade and win a Nobel
prize! :-) Behe would simply ask, "how exactly" would such
"significant changes...arise quickly rather than gradually if the
constraint on function is minimized":
"Intriguing as this scenario may sound, though, critical details are
overlooked. The question we must ask of this indirect scenario is one for
which many evolutionary biologists have little patience: but how exactly?"
(Behe M.J., "Darwin's Black Box: The Biochemical Challenge to
Evolution", Free Press: New York, 1996, p66)
SJ>And as the number of unexplained irreducibly complex biological
>systems increases, our confidence that Darwin's criterion of failure
>has been met skyrockets toward the maximum that science allows."
>SC>This is the crux of the debate. Some people cannot imagine how
>complexity could arise through naturalistic means, even if there is
>an intelligent force behind the process (e.g., ECism).
If there is (in any realsense) "an intelligent force behind
the process", then it is not solely "through naturalistic means".
SC>Other people can imagine it, and others simply say that Behe's
>criticism does not provide a sufficient basis for rejecting the
evolution model. My position is the latter.
OK. If you "can imagine it", namely any *one* of Behe's claimed
irreduciably complex systems, how about posting it? :-)
SC>Simply pointing out deficiencies in a theory is not the same thing
>as proposing a counter model. That has not been done.
The "counter model" is Intelligent Design! Any competent biologist
could come up with a detailed account of the most difficult
"irreducibly complex" system if an all-powerful, all-knowing
Intelligent Designer is allowed. For example, in the case of the
blood clotting cascade, substitute Doolittle's "Yin" and "Yang" with
'God" or "ID":
"`Blood clotting is a delicately balanced phenomenon involving
proteases, antiproteases, and protease substrates. Generally speaking,
each forward action engenders some backward-inclined response.
Various metaphors can be applied to its step-by-step evolution:
action-reaction, point and counterpoint, or good news and bad news.
My favorite, however, is yin and yang. In ancient Chinese cosmology,
all that comes to be is the result of combining the opposite principles
yin and yang. Yang is the masculine principle and embodies activity,
height, heat, light and dryness. Yin, the feminine counterpoint,
personifies passivity, depth, cold, darkness and wetness Their
marriage yields the true essence of all things.'" (Doolittle, R.F., "The
Evolution of Vertebrate Blood Coagulation: A Case of Yin and
Yang", Thrombosis and Haemostasis, 1993, 70, 24-28Behe, 1996,
pp91-92)
>SJ>His point is that *no one* has ever been able to explain even
>*one* of these complex micro-biological systems using "a
>macroevolution scenario".
>
>SC>Is this really his point--that no one has ever been ABLE to
>explain this? Or is the point simply that there are no explanations
>offered? There is a BIG difference between not offering an
>explanation vs trying trying to find one, but failing. This is an
>important distinction that is not being made here. From the
>comments on Behe's book that I have heard and read, it appears to me
>that antievolutionists overinterpret this observation.
Based on the fact that to date "no one has ever been ABLE to explain
this", Behe concludes that no one WILL ever be able to explain this".
That's a Popperian risky prediction in the best tradition of science.
All it now requires is for Neo-Darwinists to show how Behe's examples
could "have been formed by numerous, successive, slight
modifications". If they cannot do this, even in thought experiments,
then Neo-Darwinism has failed and ID, which *can* explain it, should
replace it as the more fruitful paradigm.
>SC>What does it mean that there are no published accounts that try to
>explain the origins of complex stuctures?
Just that. Behe has searched the scientific literature and found
nothing:
"....if you search the scientific literature on evolution, and if you
focus your search on the question of how molecular machines the basis
of life- developed, you find an eerie and complete silence. The
complexity of life's foundation has paralyzed science's attempt to
account for it; molecular machines raise an as-yet-impenetrable
barrier to Darwinism's universal reach." (Behe, 1996, pp5-6)
"There is no publication in the scientific literature-in prestigious
journals, specialty journals, or books that describes how molecular
evolution of any real, complex, biochemical system either did occur
or even might have occurred. There are assertions that such
evolution occurred, but absolutely none are supported by pertinent
experiments or calculations." (Behe, 1996, p185)
SC>Has it been tried and failed? Or have no attempts been made? If
>the latter, then is the question tractable to being tested
>empirically?
I would expect that there have been many "attempts" but all have
"failed". No one is yet claiming that "the question" is not
"tractable to being tested empirically". Pomiankowski agrees with
Behe that detailed case histories must be found if biochemistry
is to fall within evolutionary biology:
"At this point I find myself partly agreeing with Behe. If
biochemistry is to fall within evolutionary biology, we need detailed
case histories. Behe's trawl of the scientific literature on cilia
found only three major attempts to understand their evolution. Each
is interesting, covering issues such as the possible origin of cilia
as independent symbiotic bacteria, the use of cilia in phototaxis and
mechanical difficulties in the evolution of cilia. Evolutionary
thinking is pushing at the frontiers of knowledge. But the general
lack of interest in biochemical evolution that Behe reveals is
typical. Only in the area of DNA and protein sequence analysis has
evolution been taken seriously...To understand molecular design, we
need a biochemical account of evolution...Biochemistry is yet another
area of biology still awaiting its Darwinian revolution." "
(Pomiankowski A., "The God of the tiny gaps" reviews of "Darwin's
Black Box" by Michael Behe, New Scientist, Vol 151, No. 2047, 14
September 1996, p44-45)
SC>If so, how long has it been possible to test the question? Keep
>in mind here, that Mike also states that our understanding of
>complex molecular structures, like cilia, is much more recent that
>Darwin's model of evolution.
I would have thought that it would have "been possible to test the
question" for the last 40 years. In the above review Pomiankowski
says:
"Since the 1950s a deeper understanding of the molecular basis of
life has been possible fuelled by increasing knowledge of the
workings of DNA, molecular biology and better instrumentation."
Behe points out that Doolittle wrote his Ph.D thesis on blood
clotting in *1961*, 35 years ago:
"Russell Doolittle, a professor of biochemistry at the Center for
Molecular Genetics, University of California, San Diego, is the most
prominent person interested in the evolution of the clotting cascade
Biochemistry of Blood Coagulation" (1961), Professor Doolittle has
examined the clotting systems of different, "simpler" organisms in
the hope that that would lead to an understanding of how the
mammalian system arose." (Behe, 1996, p91)
>SC>As a counter point, one could ask how many published accounts
>describe alternative, nonDarwinian ways of arriving at complex
>structures?
Which "alternative, nonDarwinian ways" do you mean? In the case
of Intelligent Design, since it is not even considered within
science, probably none. Berlinski says that Darwinian evolution is
"doubly damned" for refusing to admit other alternatives (including
design) as explanations, yet being unable to explain the main
features of life itself :
"Unable to say what evolution has accomplished, biologists now find
themselves unable to say whether evolution has accomplished it. This
leaves evolutionary theory in the doubly damned position of having
compromised the concepts needed to make sense of life-complexity,
adaptation, design- while simultaneously conceding that the theory
does little to explain them" (Berlinski D., "The Deniable Darwin",
Commentary, June 1996, p28)
>SJ>If you believe that (say) the blood clotting cascade "evolved from
>a primordial structure by gradual improvement of" blood clotting
>ability", then why don't *you* win "instant fame" by doing it
>first, as Russ wrote:
>SC>First of all, I said that evolution by gradual refinement of a
>function, such as blood clotting, is not an a priori requirement of
>evolution.
Sorry, if "evolution" is to be a general theory of biology, it *must*
be able to explain it, or yield to a better, more general theory,
such as Intelligent Design.
SC>Second, I appreciate Mike's point that this is a hole in
>the evidence for evolutionary biology. It would be nice if his
>point stimulated some thought to "evolutionary molecular biology."
>I, however, will pass on the challenge--it's not what I do or know.
That's what they all say! :-) Nobody knows the answer in their
discipline, but everybody assumes that somebody else must know the
answer in their discipline:
"The amount of scientific research that has been and is being done on
the cilium-and the great increase over the past few decades in our
understanding of how the cilium works lead many people to assume that
even if they themselves don't know how the cilium evolved, somebody
must know. But a search of the professional literature proves them
wrong. Nobody knows." (Behe, 1996, p69)
>SC>Mike's criticism, and the discussion it has stimulated, revolves
>around the philosophical concepts of probability and liklihood--they
>are really different things. I plan to post something on this soon.
I doubt that this is what "Mike's criticism" is about at all. I
wonder if Steve has actually read Mike's book?
God bless.
Steve
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