December, 17, 2001

 

Dear Ross,

 

Over the past few months I have been thinking about your last response, but I was too loaded with deadlines to sit down and write to you before.  Now with one big project out of the way, I still have some deadlines ahead, but am taking the time to put together some comments.  First let me say that I am glad you have recuperated from your accident, and hope that you will stay well.

 

Again I will be unable to comment on everything you said, but I wanted to start by addressing several points under your heading:

 

ITEMS NO LONGER BROUGHT UP

 

1. Dawkins computer evolution model: the intermediate sequences would have had to be meaningful sentences that were useful on their own

That is correct; the intermediate sequences are assumed in the Dawkins model to have some function.  You seem to think that this assumption invalidates the model somehow. It doesn't, in my view. No model captures all the features of the process it attempts to illuminate.  Whether the model has value depends on a judgment about whether the differences between the model and the real world process are so great that they invalidate the particular points the model was designed to convey.  Dawkin's narrow point was to distinguish between the creationist straw man concept of single-step selection versus the cumulative multi-step model; and in my judgment this distinction is validly conveyed by the weasel model. I have discussed weaknesses of the Dawkins model already in the Box in my Fitness essay, and don't see that your concerns go beyond my discussion there.

 

2. Ice crystallization on the surface of a metal sphere

there is a crucial difference between the structure seen in ice, which is regular and repetitive (like ABCABCABC), and the structure in life which is full of information

 

Gish's argument that evolution violates the 2^nd Law of Thermodynamics is invalid because he ignores the following principle, which I stated at least four times in our debate: “Localized regions of increased order can occur in spontaneous processes without violating the Second Law.”  Dr. Gish claims that increased order due to life in the biosphere violates the Second Law, but he has failed to demonstrate an overall decrease in entropy associated with the development of life.  He addresses only a localized decrease in entropy of the biosphere and ignores other changes outside the biosphere that would have to be considered in any accounting of total entropy changes.  Therefore, he has not demonstrated any violation of the Second Law, since localized entropy increases are not a violation.  If you disagree with the principle I quoted above, please explain why.  The model of ice on the copper ball that I discussed at the debate was merely an illustrative example meant to help the audience comprehend the principle about localized increased order not violating the Second law.  The differences you focus on in your criticism (information vs. ABCABCABC) are irrelevant to the validity of the quoted principle, and are also irrelevant to my point that Gish's argument is invalid because he has not made a full entropy accounting of any defined system.  Therefore, I still consider my complaints against Gish's argument to be valid.  Incidentally, have you read the article I recommended on this point by Allan Harvey, an expert in thermodynamics (who is also an evangelical Christian) at the URL below?

http://members.aol.com/steamdoc/writings/thermo.html

If you still think Dr. Gish's argument is correct, perhaps you could comment individually on the following:

(1) Do you agree that “Localized regions of increased order can occur in spontaneous processes without violating the Second Law”?

(2) Do you think that a valid thermodynamics analysis of the biosphere can neglect the sun's energy and the dissipation of solar energy into space?

(3) Do you really think that either you or Dr. Gish knows more about thermodynamics than a professional like Dr. Allan Harvey?

 

3. Generation time of fruit flies and bacteria: we should have seen more dramatic changes in fruit flies and bacteria . . . .

how about the 20 minute generation time of a bacterium? In that case, 50 years of observation is equivalent to about 25 million years of an organism with a 20 year generation time. And, I think, we have been observing bacteria for more like 100 years. 

 

This is an extension of your previous argument:

 

A lot is supposed to happen in 25 to 50 million years. Humans are supposed to have differentiated from Australopithecus-like creatures over only a couple of million years! In the Cambrian explosion, all sorts of multi-cellular organisms in a plethora of sizes and shapes appeared "suddenly." Why have we not seen these little micro-organisms going macro? Or "postal?" Or unionizing? Or showing specialization of some sort?

 

Think about it! Even if you want to quibble about the numbers, where are the incipient organs? Where are the first, second and 43rd of those multi-step stages that are leading to something wonderful for their kind? Or do we just happen to always examine only organisms that prefer "stasis?" Isn't that like the invisible and totally undetectable "pink elephant" usually associated with irrational religious beliefs?

 

 

According to the evolutionary perspective, the rough time line for early life based on the fossil record and on dating as accepted in the geological literature is:

4.5 BYA             Earth formed

3.5 BYA            First prokaryotic cell

1.5 BYA            First eukaryotic cell

0.7 BYA            Multicellular organisms

Given these dates in the evolution model, the laboratory experiments on “evolution in a test tube” would not be expected to duplicate bacteria “going macro,” since the lab experiments involve tiny fractions of the millions of years required for the kinds of changes you describe.  Part of the reason that it may have taken so long to go from the first bacteria to the first eukaryotic cell is that, if modern organisms are any guide to the genome sizes of these “firsts,” a large expansion in DNA and gene content would have been required.  (Several free-living bacteria have 1.5 million bp of DNA, and only about 1500-1700 genes, while the simplest eukaryote yet sequenced, a yeast, has roughly 12 million bp and 6000 genes.)  This expansion would take considerable time, even in rapidly proliferating species of bacteria.  In contrast, the evolution from Australopithecus to human occurred without any significant increase in DNA or gene content (if modern apes are any guide) and could have occurred much more rapidly.  You ask why lab experiments don't produce “incipient organs,” but I can't think of any totally new organs that evolved in land mammals even in the millions of years since the mammalian radiation.  We have seen changes in size, and structural changes to accomplish changes in function (forelimbs adapted for flying for instance, or foregut swelling to become ruminant rumen, or hindgut outpouching to become skunk's spray gland), but these are not totally new organs, and may in any case have taken tens of millions of years to evolve.  So I can't see why you think evolution predicts that we should see new “incipient organs” in short-term laboratory evolution experiments.  If you want to consider examples of rapid changes through random mutation and selection, one example is the diversification of dog breeds over the past 10,000 years, leading to great differences in body size and shape.  This “experiment” of evolution has led to very rapid phenotypic changes with minimal genomic change.

 

 

 

4. Michael Behe's concept of irreducible complexity

Behe has shown how [step-by-step evolution] is impossible because an irreducibly complex structure must be complete to be functional and cannot be produced by small steps and gradual approximations.

 

Behe's concept of irreducible complexity ignores the possibility that a component that is now critical for the function of a modern biomolecular structure may have evolved from a non-essential component in an earlier version of the structure, a version that had a different function than the modern homolog.  The example given by H. Allen Orr in his review of Behe's book is appropriate to illustrate the concept: a lung is now critical for us but appears to have evolved from a swim bladder.  The swim bladder was not critical for survival of the fish in which it arose, since it merely assisted in “ballast control,” while the critical function of oxygenation was performed by the gills.  Clearly we cannot access the molecular precursors of the clotting system or bacterial flagellum because these structures evolved millions of years ago and proteins don't leave “fossil” evidence.  Thus we can't document how the protein components that are currently critical for a flagellum may have evolved as beneficial but not essential components of a precursor structure that had a function different from active motility; but there is no reason to conclude that such precursors did not exist.  In his book Behe neglects this idea, repeating over and over again how the CURRENT system requires each component to get any function, while ignoring the possibility that individual components may have been dispensable in more primitive homologs with different function.  Because Behe ignores this central point, his argument is unconvincing to evolutionary scientists. 

 

Of course, some Behe followers have gone further and claimed that it is impossible even to conceive of precursors that lack a given component of an IC structure.  This puts evolutionists in a strategic bind.  If they propose a speculative scenario as a possible explanation for how such structures may have evolved, such scenarios are pounced on by creationists as “just-so stories.”  Yet if they decline to propose a speculative scenario, creationists claim that this proves there are no conceivable evolutionary paths to modern “IC” molecular systems.  Evolutionists accept the fact that we cannot access scientific evidence of molecular structures hundreds of millions of years old, but this does not lead them to conclude that these structures did not exist.  It is a historical fact that as recently as 40 years ago, no one had conceived of the recombinational mechanisms that generate antibody diversity, but these mechanisms are now well known.  Perhaps 40 years ago some Behe-like scientists could have claimed that each antibody amino acid sequence had to be intelligently designed for a particular antigen because it was impossible to conceive of a satisfactory naturalistic explanation; but those scientists would have been wrong.  Similarly, the fact that we may not at present be able to conceive of the evolutionary path that led to a modern “IC” molecular structure is no reason to conclude that this structure did not evolve.  Most scientists other than Behe have the humility to recognize that our ignorance is profound and that evolution may be “smarter” than we are; Behe seems to feel that anything he doesn't know can't really exist. 

 

In other words, you need to show how a bacterial flagellum can be built by small changes in successive generations, each of which would survive because it is of selective advantage to that individual.

 

To contradict the notion that a naturalistic evolutionary path to the flagellum cannot be conceived, I would like to describe such a path, even though it cannot be any more than a speculation, so it is vulnerable to the “just-so” criticism.  We start with an initial bacterial species with no flagellum and living in moving water.  It can extract some nutrients from the mud it contacts, but only if it sticks around long enough to carry out certain biochemical reactions.  Some bacteria evolve a surface protein that attaches to molecules on a solid support like rock or sand grains in the mud and prevents the cell from being swept away by currents; and this strain of bacteria prospers and multiplies.  The next development is that after using up all the nutrients within reach, the bacteria run into a metabolic dead end, until some cells evolve hair-like projections fastened to the cell wall that allow them stick to their sand grains but to forage nutrients over a wider area without being swept away by the water currents.  (These are similar in structure and function to modern bacterial pili.)  The next step is that these hair-like projections get longer (allowing a wider area for foraging nutrients) until some bacteria die when water currents spin them around and twist off their hair-like projections.  Then some bacteria evolve a mechanism that allows the projections to rotate with respect to the surface of the bacteria so that the hair-like projections don't get twisted when the current spins the cells.  When these molecular swivels become efficient, bacteria whose growth is prevented by limiting energy supplies evolve a mechanism for converting the mechanical energy of rotational motion at the base of the hair projections into ATP; they do this by borrowing components of the F1 ATPase already evolved to convert rotation into ATP.  When this mechanism for converting rotational energy into ATP has evolved, some bacteria that have become detached from their sand grains evolve a mechanism for running the conversion mechanism backwards, i.e. so that ATP is used to generate rotation of the hair projection to provide motility.  Voila, a primitive flagellum, evolved by multiple sequential steps, in which each individual component is dispensable when added because the earlier versions of the complex provide a function different that of the modern homolog, motility.  Obviously I don't claim that this is necessarily the true evolutionary path that led to the bacterial flagella since we have no way to access that path, but I offer this scenario to show the worthlessness of the idea that no such path is conceivable.  (Also, there is some evidence for sequence similarity between archaeal bacterial protein components of flagella and pili [Bayley & Jarrell J Mol Evol 46:370, 1998]).

 

Thus for each of your four “items not brought up,” the fact that I didn't previously address them does not mean that I had conceded that my earlier position was invalid.

 

 

You have said that I have “vilified” Dr. Gish and used  ad hominem arguments against him, and that you reject my invitation to “bash Gish”;  and you say “a man of science would simply deal with the concepts without having to constantly snap back to character assassination and well poisoning.” I find these accusations totally ridiculous, as it is YOU who have steadfastly refused to “deal with the concepts” that I brought up (except for the thermodynamics issue).  I have never vilified Dr. Gish or suggested that everything he says is false, but have only pointed out errors in specific arguments he has made, and you have refused to discuss them.  I have agreed to discuss other creationist arguments after we deal with your claim that I was unfair in my criticisms of Dr. Gish.  I can only conclude that you agree that Gish's arguments are erroneous (i.e. to consider them would be to “bash” Gish); but that you will never be willing to admit that a creationist argument is flawed, even if you know that to be the case.  Our whole discussion started as a result of your criticisms of the points I made at the debate against Dr. Gish's arguments.  What's the point of continuing our discussion if you refuse to consider whether points I have made are valid? 

 

In addition to pointing out erroneous arguments of Dr. Gish, I have also challenged his scientific integrity for implicitly claiming expertise in an area he had no knowledge of, and for repeating erroneous claims without bothering to check the scientific literature after his errors had been pointed out.  You persist in fantasizing scenarios that you think would somehow excuse these behaviors.  I'm not that interested in discussing Dr. Gish's integrity, and would just as soon drop that issue.  But if we're not going to discuss the validity of creationist arguments – which I thought represented the main reason you contacted me after the debate - let's just drop the whole correspondence.

 

Before closing, I will make a few brief comments on some of your other points.

 

you are agreeing with the MAIN POINT of creationist challenge to a naturalistic origin of all things

 

I give no credit to creationists for trumpeting our ignorance about the origin of life.  They have made no contribution.

 

evidence against a naturalistic origin of ANYTHING is automatically evidence for its creation,

 

Ignorance about the naturalistic mechanisms that may have given rise to life is not the same thing as “evidence against” a naturalistic origin.

 

faith in the establishment that is unjustified by a fair reading of the history of science or scholarship

 

I have no “faith” that the science in professional journals is always correct.  But I believe that is the best source we have for scientific information and that it should serve as the basis for what is taught in science classrooms. 

 

One conclusive proof of design trumps all the plausible scenarios of natural origin and one conclusive case for a young earth overturns all the old age arguments.

 

There is no conclusive proof of design or of a young earth.  Science rarely advances on the basis of conclusive proofs anyway.  A preponderance of evidence is all we should ever expect, and that is what we find supporting evolution in the scientific literature.

 

Although I do not expect you to necessarily review and critique all these articles which are obviously outside of your main areas of interest and expertise, I hope that you do notice that these are scholarly writings, most of which are published in peer reviewed journals within the creationist community.

 

I will continue to look at the creationist journals, and again express my thanks for the subscriptions.  So far I have been impressed with a level of scholarship above that of Dr. Gish, but still below that expected in the mainstream science literature.

 

evidence for design does not have point to a designer because you have a hypothesis

 

If we had evidence of design, it would point to a designer.  What we have, however, is evidence for complex adaptations.  These could be the result of intelligent design, but could alternatively result from evolution. 

 

What I honestly need to know is whether you think it theoretically possible that "good science" could be done from a creationist perspective or whether the two are mutually exclusive.

 

I believe “good science” rests on the scientific method of using observable evidence to choose from competing hypotheses using unbiased deductions.  To the extent that creationist science depends on the bible rather than on observable evidence, it is not, in my view, good science.  But I think it is theoretically possible that creationists could uncover evidence that would seriously challenge evolution and be “good science.”  So far, however, nothing that I have seen from creation “scientists” falls into this category.  The arguments from Dr. Gish and the ones you mentioned about a young earth are typical: they rest on flawed data or on flawed reasoning.

 

I have enjoyed our correspondence, and wish you the best.

 

Sincerely,

 

Ed