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Untangling Evolution (A *MUST* Read)
First Things ^ | Stephen M. Barr

Posted on 12/30/2001 2:08:09 PM PST by Exnihilo

Untangling Evolution


Stephen M. Barr


Copyright (c) 1997 First Things 78 (December 1997): 14-17.

There’s no denying that historically evolution has been harmful to religious faith. It has contributed to undermining confidence in Scripture and to promoting a naturalistic view of man. In our own age, such atheists as Daniel Dennett, Richard Dawkins, Stephen Jay Gould, and Carl Sagan have claimed that natural selection destroys the Argument from Design and with it any reason to believe in God. But if we can set aside the historical effect of the theory of evolution—and set aside the theological meanderings of those who want to use the theory as a stick with which to beat religion—we can find that nothing in the theory itself creates intellectual difficulties for Christian or Jewish belief. Evolution raises important questions for faith, but not difficulties.

In The Blind Watchmaker, Dawkins argues that natural selection can give "design without design." The "watch" of the title refers to the famous argument of William Paley, and in this context stands for the intricate structures to be found in the biological world, which many think give proof of a divine Maker. There is no maker, says Dawkins, except the universe itself—his "blind watchmaker."

To eliminate design, as Dawkins would do, one must have some mechanism that produces form from formlessness, order from chaos. But no scientific explanation does this. Science explains order by deriving it from order. Consider the formation of crystals, an oft-cited example of the spontaneous emergence of order. The patterns exhibited by crystals are a reflection of underlying symmetries and principles of order that apply to the atoms themselves, to the space in which they move, and to the laws that govern their behavior. These, in turn, can be traced to deeper levels of physical law. No matter how profoundly one penetrates into the hidden workings of the world, it is not some formless flux that is encountered, but ever more remarkable and beautiful structure.

And this is just the point. To have evolution one must have a universe. And not just any universe will do. Rather, it is beginning to appear that the laws of nature must be carefully arranged. The facts of evolution, like the facts of reproduction, are no less astonishing for being natural. If they are natural we should be astonished at the laws of nature. What immortal hand or eye framed their fearful symmetry? Perhaps none, if the laws themselves also evolved by some process analogous to natural selection. But that would put us back where we started, since any such process must itself have been governed by laws of some kind.

The Argument from Design remains perfectly healthy, then, even if we concede to natural selection all that is claimed for it by the most naturalistic theory of evolution. But, as it happens, there is no reason to concede so much to it. It is far from clear that natural selection is really up to the job, not only of crafting complex organisms, but even of explaining what goes on in the simplest living cell, as the molecular biologist Michael J. Behe has amply demonstrated in his recent book, Darwin’s Black Box. Moreover, the times available for natural selection to have worked these wonders were far shorter than was commonly supposed. The Cambrian Explosion, that wild proliferation of new forms of life that occurred about 540 million years ago, took only a few million years. And it is now generally admitted that most species make their appearance in the fossil record quite suddenly, geologically speaking.

Unfortunately, many religious believers—and not only biblical literalists—have taken this argument one step further than it has to be or ought to be taken, to deny that life on earth has a common ancestry. I find this quite puzzling. If it can be shown that a reptile cannot evolve into a mammal or a fish into an amphibian by natural selection alone, then there must have been divine intervention. Nothing is added to the force of this argument by denying that the reptile or the fish did so evolve. The atheist is out on a limb, so why try to saw down the whole tree, especially against the grain of so much evidence?

The evidence for the common ancestry of life is very strong. To give some idea of what it is, I will simply list a few of the kinds of questions that common ancestry gives an answer to. Why is it that bats and whales have so much in common anatomically with mice and men? Why do virtually all vertebrate forelimbs have the same basic "pentadactyl" (five-fingered) design? (This is one of numerous examples of "homologous" structures exhibited by related species.) Why do some species of whales have vestigial and quite useless pelvic and leg bones, when they have no pelvises or legs? Why are all mammals native to Australia marsupials? Why is there a sequence of reptiles in the fossil record (the "therapsids") with a clear progression from reptilian to mammalian characteristics? Why does the record of life on earth show a clear trend towards greater complexity? Why is it found that the most ancient bird fossils are reptilian, and the most ancient whales have feet? Why do salamander embryos have gills and fins that they will never use?

The point in asking these and many similar questions is not only that common ancestry can answer them, but more significantly that no real answer on any other basis has been found to any of them. (There is certainly no theological explanation of why bats, humans, frogs, and lizards all have five fingers.)

Unanticipated discoveries in various fields have strengthened the case for common ancestry. The theory of plate tectonics and continental drift resolved a number of evolutionary puzzles (though some remain, such as the existence of the platyrrhine monkeys of South America). And dramatic confirmation has come from gene and protein sequencing. Particularly striking is the phenomenon of "molecular clocks." (This refers to data obtained by comparing certain proteins and nucleic acids in different species. It is found that the variation of these molecules from species to species over a vast taxonomic range exhibits patterns that are hard to explain unless one assumes that the molecular degree of difference between two species is in some cases a measure of the period of time that they have been evolving separately—that is, since they had a common ancestor.)

Let us suppose not only that evolution (that is, the common ancestry of all life on earth) is true, as I think the evidence shows, but that natural selection is a sufficient mechanism for it, which the evidence does not show. What difficulties would that create for religious belief? Unfortunately, the issues are sometimes clouded by a failure to make distinctions.

The critical distinction is between divine intervention and the other ways God acts. By "intervention" I mean something that goes beyond the order of nature, an effect produced by God in the world that contravenes either the laws of nature or the laws of probability. Intervention is not to be confused with providence. While faith tells us that all events are governed by providence, divine intervention is rare. Even events in which we think we can discern the hand of providence do not usually involve anything beyond what is naturally possible. A child’s voice in a garden is nothing extraordinary, and yet St. Augustine heard such a voice and it changed the course of history.

Creation means that God brings into existence all that is, and providence and design mean that He orders all that is. These concepts do not necessarily imply intervention. It is true that the account of the creation of plants and animals in Genesis is suggestive of intervention: there is no mention there of natural processes (unless they are hinted at when Genesis says that the earth and waters "brought forth" the various living creatures). But Genesis describes the creation of the sun and stars in a way that is even more suggestive of divine intervention. (The firmament does not "bring forth" the sun; God "sets" it there.) Yet modern astrophysics has an adequate naturalistic explanation of the formation of the sun and stars, which is not challenged even by most of those who question evolution.

The sun is an ordinary star, and there are many billions like it. But if the laws of nature were in certain respects even slightly different, no such stars would exist, and hence life as we know it would not exist either. Even apart from faith, therefore, we can recognize the role of providence and design in the existence of the sun and stars, although it is now clear that no intervention was required to produce them.

There are those who argue, nevertheless, that a consistent—or at least a full-blooded—theism requires intervention for the production of living things, since the alternative to intervention is a "naturalism" based on "blind forces" and "chance." "Naturalism" can be the denial that anything whatever goes beyond the nature of material things. Such naturalism denies a priori even the possibility of divine intervention, because it denies the existence of God. But not all naturalism is of this kind. There is also a naturalism whose opposite is the prescientific view of nature that one finds among primitive peoples. This naturalism is based on true progress in knowledge of the physical world. Science finds no signs of divine intervention in the realm of inanimate matter. In astrophysics, geology, chemistry, or plasma physics, for example, one does not encounter the miraculous.

In the human sphere things are different. Both faith and reason tell us that man has a spiritual soul, and therefore that purely naturalistic accounts of human realities are false. We believe, as well, that divine intervention has happened in human affairs, in particular in the miraculous events of salvation history.

Since the world of plants and animals is intermediate between the human and the inanimate, it is not obvious whether we should expect to find signs of intervention there. Ironically, there are stronger grounds for expecting it if human beings did evolve. If there had to be reptiles for there later to be men, then it would seem quite in character (if one may speak so) for God to have intervened to produce reptiles, by arranging, say, the necessary mutations or selective pressures.

On the other hand, one might expect no intervention in those parts of the biological world that do not involve man in any significant way. There is an excellent book called Evolution: A Theory in Crisis, which has deservedly become a classic of the anti-Darwinian literature. (It presents the arguments for evolution with exemplary fairness and honesty, and it should be noted that its author, Michael Denton, has since come to believe in evolution.) Among many other fascinating things, one can find in this book a discussion of the copulatory apparatus of the male dragonfly, which is apparently a prodigy of complexity and quite unique in the insect world. How, Denton asked, could such a thing have been produced by natural selection? That question is difficult to answer, but maybe no more so than the following one: Why would God, Who so rarely intervenes in nature, do so to produce a unique way for dragonflies to copulate?

A clergyman at a conference on the subject of creation, overhearing me pose this question, inquired with some slight sarcasm whether I had received any telegrams from the Almighty answering it. But I do not think it necessarily absurd to ask what God would be likely to do, for though God’s ways may often seem inexplicable to us, God is not arbitrary. I believe that Isaiah foretold future events. But I do not believe that Jeanne Dixon was able to do so. God’s interventions have followed a pattern, and Jeanne Dixon does not fit it. A presumption in favor of a natural explanation in a particular case, then, can be a result of theological considerations, rather than of atheistic or materialistic presuppositions.

There is much talk on both sides about "blind forces" in connection with evolution. But there is nothing in such an idea that should shock a Christian or Jew. It is not the forces of nature that see, but God. Indeed, it is precisely the blindness of nature that allows us to recognize that events must be guided by something beyond nature, by providence rather than by fate, or destiny, or occult forces. The blindness of nature argues against pantheism and all of nature-worship ancient and modern, not against theism. The idea that God works His will through blind agents is as biblical as the story of Joseph in the Old Testament. The notion of blind natural forces came not from a rejection of God, but of Aristotle, and in particular of his teleological physics. It was this that made modern science possible, and it did not result from a conflict between naturalism and supernaturalism, but from a conflict between two kinds of naturalism.

Similar ambiguities surround the notion of "chance." Evolutionists ascribe things to "random" mutations, and many feel that this in itself involves a denial of a rational cause or design. But the notions of chance, randomness, and probability are notoriously subtle. A simple example will illustrate this. It is well-known that the most common letter in English is "e," followed by "t," and then "a." These are statements about probabilities. As it happens, they hold true for the Gettysburg Address, as they do for most sufficiently long passages in English. But no one should doubt that Lincoln crafted this speech with great care, with every word—and consequently every letter—chosen to serve a purpose. By analogy, the fact that God’s providence extends to every event in the universe does not imply that notions of chance and probability will not apply to them. The mutations that led from the first single-celled creature to the genus Homo may have been chance events from a certain point of view, but as Pope John Paul II has said, every one of them was foreseen and willed by God. (I hasten to add that none of this is to suggest that it has been shown that random mutations and natural selection are sufficient as a mechanism of evolution. As of this moment, I would say, the arguments favor those who deny this.)

What troubles most people about evolution is its application to human beings. One reason is that some think it degrading to have apes as ancestors. But it is not obviously more dignified to have come directly from slime. A deeper reason is the discontinuity that we know to exist between human beings and the rest of creation—between spirit and matter. Yet it is hard to see that this is more of an issue for evolution than it is for human reproduction. We are in no position to observe the immediate antecedents of Adam, but we know that those of each human child today were a sperm and an egg, which are without doubt purely material in themselves.

The real question is whether man is more than a mere arrangement of atoms. If he is, then it would seem to matter little how those atoms came to be arranged as they are, whether by natural processes of evolution or reproduction, or by supernatural intervention. Pope John Paul II and Pope Pius XII have indicated the essential point: As long as we maintain the scriptural and philosophical truth that man has a spiritual nature, there can be nothing to fear in merely biological facts.

It is otherwise for the atheist. It is his faith that is at stake in this controversy, not ours. His faith requires that chance and natural law must be adequate to explain the facts of evolution. If they do not appear to be adequate, he must nevertheless insist that they are. It is for him, then, to dogmatize about strictly scientific matters, not for us. We can be content, and should be content, to be guided only by the evidence.


Stephen M. Barr is Associate Professor of Physics at the Bartol Research Institute, University of Delaware.


TOPICS: Editorial; Miscellaneous
KEYWORDS: crevolist
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To: tortoise
Perhaps because they assumed that it was sufficiently basic as to be "obvious".

Obvious? Then why isn't there even a theoretical model for informational generation in biological systems?

Your summary of thermodynamics was very laughable. Why not give me an instance of this information creation. I'll be waiting, but I won't hold my breath.
41 posted on 12/31/2001 5:19:41 AM PST by Exnihilo
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To: balrog666
Scientific explanations of seemingly miraculous events have always rocked they faithful as those events were used to convince the stupid of the "unknowable" in the first place. So what?

This is so vague as to be meaningless. What, specifically, has been discovered that "rocked the faithful"? Why were the founders of science Christians? Please, be specific and cite historical discoveries and their applied usage by people to convince "the stupid" of the unknowable. In closing, declaring something "tripe" is as vacuous as your statements are. It's a meaningless assertion of your own dislike for the author's comments, however if you insist on stopping there and not reading any further, you will remain an ignorant troll on this thread. Good day.
42 posted on 12/31/2001 5:23:36 AM PST by Exnihilo
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To: jennyp
Amino acids & nucleic acids spontaneously link & form longer & longer chains on the surfaces of minerals, even up to lengths where functional proteins & RNA start to be found.

Dear god.. you actually believe that? LOL! And dear, if you had half the intellectual honesty that you pretend to, you might have spent five minutes looking for Dembski's responses to his critics. I would also put down a large sum of cash betting that you've never even read one of his books.
43 posted on 12/31/2001 5:25:53 AM PST by Exnihilo
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To: jennyp
And pointing to Ken Miller? Puuhhlease.. I'd bet, again, that you haven't looked for critics of Miller's work have you? For shame Jenny. I thought you were better than that.
44 posted on 12/31/2001 5:27:13 AM PST by Exnihilo
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To: jennyp
Why spend your time trying to fight the consensus view of modern biological science?

Why spend your time trying to fight the consensus view of modern astronomical science prior to say 1400?
45 posted on 12/31/2001 5:28:40 AM PST by Frumious Bandersnatch
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To: Exnihilo
Today:

I hope we all remember this. It is the atheists who are on the defensive. Those of us who are theistic have nothing to concern ourselves with, other than destroying materialism, which is of course, all but done at this point.

To jlogajan:

First, I am not a Creationist. I am however, quite intrigued by your desire to cast me as one. What are you hoping to accomplish by this repetative behavior?

So, really, what's your story?

46 posted on 12/31/2001 5:30:42 AM PST by VadeRetro
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To: Exnihilo
The author questions why there are so many similarities among the species. Whether one believes in evolution or not, he poses the question as if there were only one answer. Could not the answer also be that all species were created by the same designer?

Why do the paintings of Salvador Dali look like they were painted by..... Salvador Dali? Did all evolve from one painting, or were all just created by the same artist?

Arguments may be made for evolution, but this is surely not one of its stronger arguments.

47 posted on 12/31/2001 5:51:22 AM PST by joathome
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To: Exnihilo
It's a meaningless assertion of your own dislike for the author's comments

BWAHAHAHAHA!

I read your various comments in exactly the same way. You seemingly have nothing to say and respond to the discussion with condescending assertions unrelated to the argument or reality.
48 posted on 12/31/2001 5:58:17 AM PST by balrog666
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To: Exnihilo
So that everyone will have access to the accumulated "Creationism vs. Evolution" threads which have previously appeared on FreeRepublic, plus links to hundreds of sites with a vast amount of information on this topic, here's Junior's massive work, available for all to review: The Ultimate Creation vs. Evolution Resource [ver 12.
49 posted on 12/31/2001 6:33:09 AM PST by PatrickHenry
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To: VadeRetro
What difference does "my story" make? I'm not a Creationist, that's all I know. Let's stick to the post at hand, okay? Thanks.
50 posted on 12/31/2001 7:08:22 AM PST by Exnihilo
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To: balrog666
In other words, you have no actual substance to your assertions. I asked you to be specific and cite examples. I don't think that's unfair, do you?
51 posted on 12/31/2001 7:09:32 AM PST by Exnihilo
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To: Exnihilo
In other words, you have no actual substance to your assertions. I don't think that's unfair, do you?

Actually, that's what I said of your arguments. I disputed your generalities with my own and now you want specific examples? If you have a point, make it or stick it.
52 posted on 12/31/2001 7:27:34 AM PST by balrog666
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To: Exnihilo
Obvious? Then why isn't there even a theoretical model for informational generation in biological systems?

Information generation has no intrinsic mathematical or scientific relationship to biology any more than there is a theoretical model for gravitation in a ham sandwich. To assert otherwise is sheer cluelessness. Therefore, I will attempt to narrow down exactly what you mean by "informational generation".

It is questionable what you mean by "information generation" since "information" is a suitcase term that has very specific mathematical definitions that are quite different than many common definitions. If we were talking about something as simple as, say, concept formation in the brain (i.e. the process of thinking) you would be wrong to assert that there is informational generation that violates thermodynamics, as the processes create a net increase in entropy that is roughly 10^8 times greater than the decrease in entropy due to concept/thought creation. The DNA in living things behaves exactly like any other molecule, requiring an entropy/enthalpy gradient to execute its complex behaviors. Lacking an external gradient, the process stops.

The bottom line is that information creation is perfectly permissible with the caveat that the net entropy of the system is always increasing. Biological systems create vast quantities of entropy in their reproductive and complexity building processes, and the only reason it has been sustainable is that the solar system has a very large enthalpy gradient (from the sun mostly) that is being used up and converted into entropy as rapidly as possible in the process of building complex biological systems and organisms. If the sun went dark tomorrow, the process of "informational generation" would grind to a halt as it is an endothermic process ultimately. Which is all exactly what basic thermodynamics predicts (2nd Law and all that).

Does this answer the question?

53 posted on 12/31/2001 9:38:07 AM PST by tortoise
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To: Tom D.
What you describe is not evidence of evolution but is evidence of an inherent ability of the micro-organism to adapt. The organism's ability to adapt is already there. Adaptation is seen in what evolutionist's term, "higher" organisms: e.g., moths, rabitts, chameleons, etc. Animals adapt to any number of external stimuli all the time without failing to reproduce after their kind.
54 posted on 12/31/2001 9:57:04 AM PST by Agamemnon
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To: Exnihilo
Amino acids & nucleic acids spontaneously link & form longer & longer chains on the surfaces of minerals, even up to lengths where functional proteins & RNA start to be found.

Dear god.. you actually believe that? LOL!

The mineral surfaces are catalysts. Catalysts are substances that do great damage to creationist impossible odds arguments.

Most theories of the origin of biological organization assume that polymers with lengths in the range of 30-60 monomers are needed to make a genetic system viable. But it has not proved possible to synthesize plausibly prebiotic polymers this long by condensation in aqueous solution, because hydrolysis competes with polymerization. The potential of mineral surfaces to facilitate prebiotic polymerization was pointed out long ago. Here we describe a system that models prebiotic polymerization by the oligomerization of activated monomers--both nucleotides and amino acids. We find that whereas the reactions in solution produce only short oligomers (the longest typically being a 10-mer), the presence of mineral surfaces (montmorillonite for nucleotides, illite and hydroxylapatite for amino acids) induces the formation of oligomers up to 55 monomers long. These are formed by successive 'feedings' with the monomers; polymerization takes place on the mineral surfaces in a manner akin to solid-phase synthesis of biopolymers.
Ferris, Hill, Liu, & Orgel. 1996 May 2. Synthesis of long prebiotic oligomers on mineral surfaces. Nature, 381, 59-61.

What part of this study do you laugh at? And if you say it's the fact that it's a human-designed experiment, you lose. :-)

55 posted on 12/31/2001 11:20:56 AM PST by jennyp
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To: Agamemnon
What you describe is not evidence of evolution but is evidence of an inherent ability of the micro-organism to adapt. The organism's ability to adapt is already there.

Ah, but bacteria that were cloned from a single initial bacterium also develop antibiotic resistance! IOW, if you take a single bacterium & place it into a nutrient solution that has first been sterilized in an autoclave, and let it split into a new colony of clones of itself, and then apply selective pressure to this colony over many generations, it will still eventually "adapt" to thrive in the new environment.

This is due to brand-new mutations appearing in the colony and getting selected for/against. The "inherent ability to adapt" in your sense was not there initially.

Bacteria are easy to study. This is an advantage in evolutionary studies because we can see evolution happening in the laboratory. There is a standard experiment in which the experimenter begins with a single bacterium and lets it reproduce in a controlled environment. Since bacteria reproduce asexually all of its descendents are clones. Since reproduction is not perfect mutations happen. The experimenter can set the environment so that mutations for a particular attribute are selected. The experimenter knows both that the mutation was not present originally and, hence, when it occurred.
Richard Harter, Are Mutations Harmful?, TalkOrigins

56 posted on 12/31/2001 11:36:15 AM PST by jennyp
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To: jennyp
The experimenter can set the environment so that mutations for a particular attribute are selected.

Playing the Devil's Advocate here, I can set the environment for changing a solid into a liquid and then back again in my kitchen using simple plastic trays; isn't the keyword in this and all such experiments the reliance on a suitable chance environment for the natural world to be so explained?

57 posted on 12/31/2001 11:55:31 AM PST by Old Professer
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To: Exnihilo
What difference does "my story" make? I'm not a Creationist, that's all I know. Let's stick to the post at hand, okay? Thanks.

OK, this article says "Yes, there's what looks like evidence from multiple lines of evidence for common descent. However, you can in every case explain the same thing by the intervention of My Invisible Buddy."

True, you can explain anything you see in terms of magic or Goddidit. That's one sign of a totally useless theory. And why then does the evidence also fit evolution? Fitting evolution's a lot harder. One rabbit fossil in the Precambrian, etc., etc. And why do we need supernatural explanations at all, much less why should they be the default? And what's the evidence for supernatural explanations?

58 posted on 12/31/2001 12:47:20 PM PST by VadeRetro
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To: Exnihilo
And pointing to Ken Miller? Puuhhlease.. I'd bet, again, that you haven't looked for critics of Miller's work have you? For shame Jenny. I thought you were better than that.

This is an old debate on FR. It took me a while, but I finally found Miller's (longer) online version of his book chapter, where he goes into detail about the blood clotting cascade.

Here's Behe's critique of Miller's original published description of blood clotting evolution. He complains that Doolittle's model (by way of Miller) doesn't take into account the evolution of regulatory methods, the lack of which in a modern mammal would kill it.

Here's Miller's response to Behe's critique. Here's Miller's original draft of the part of the IC chapter concerning blood clotting. As I suspected, Behe's complaints about lack of regulation destroying the organism before the new clotting steps could get refined are based on what would happen in a modern, high-blood pressure organism like humans, instead of the more realistic low blood pressure organism where the evolution of blood clotting really got started.

IOW, Behe's critique of Miller/Doolittle is an airball. It tries to cut off evolution at the start - in a small ancestor organism 600 million years ago - but does so by judging it according to the conditions of a wholly different organism!

Or as Miller puts it...

Behe asserts that the targeting of a protease, a digestive enzyme, to the bloodstream is a "potentially deadly situation," and tells the readers of his web document that we can tell how deadly this might be by looking at situations "where regulatory proteins are missing from modern organisms." In other words, Behe wants us to look at what happens when the highly-regulated current versions of clotting proteases are missing their regulatory factors. Despite this bluster, however, Behe has no evidence that the mistargeting of an inactive protease to the bloodstream would cause harm. Indeed, the recent discovery that antifreeze protein genes in fish arose from exactly such a mistargeting of proteases into the bloodstream (Chen, L., DeVries, A. L. & Cheng, C.- H. C. Proc. Natl Acad. Sci. USA 94, 3811­3816 (1997); and Chen, L., DeVries, A. L. & Cheng, C.-H. C. Proc. Natl Acad. Sci. USA 94, 3817­3822 (1997)) suggests that exactly the opposite is true.

Having made unsupported claims about the "danger" of such a mutation, Behe says that it would be difficult to see what "advantage" this would present to the organism. The answer, of course, is that it would provide a slight improvement in the organism's ability to clot blood - and that's the point. The clotting system doesn't have to work full-blast right away. In a primitive vertebrate with a low-pressure circulatory system, a very slight improvement in clotting would be advantageous, and would be favored by natural selection.

Behe then wonders how the circulating protease could become localized at the site of a clot, as if this were an insurmountable difficulty. It's not. As I suggested in my original draft on the evolution of clotting, a well-understood process called exon shuffling could have placed an "EGF domain" onto the protease sequence, and the "problem" that Behe puzzles over is solved in a flash.

Finally, Behe emphasizes that the real problem is not to generate a clot - it is to "regulate" that clot by means of an inhibitor of the protease so that it doesn't become destructive. But that's not a problem for evolution, either. As usual, Behe envisions a clotting protease that is just as powerful as the fully-evolved proteases in modern vertebrates. However, remember that this is the same guy who fretted a moment or two ago that the protease would not be strong enough to clot effectively. He wants to have it both ways. The answer to his objection is just what I wrote in the draft:

" ... a primitive clotting system, adequate for an animal with low blood pressure and minimal blood flow, doesn't have the clotting capacity to present this kind of a threat. But just as soon as the occasional clot becomes large enough to present health risks, natural selection would favor the evolution of systems to keep clot formation in check. And where would these systems come from? From pre-existing proteins, of course, duplicated and modified. The tissues of the body produce a protein known as alpha-1-antitrypsin which binds to the active site of serine proteases found in tissues and keeps them in check. So, just as soon as clotting systems became strong enough, gene duplication would have presented natural selection with a working protease inhibitor that could then evolve into antithrombin, a similar inhibitor that today blocks the action of the primary fibrinogen-cleaving protease, thrombin."

In short, none of the points raised by Behe are adequate to explain why the vertebrate clotting system could not have evolved. Furthermore, as Doolittle's work has shown clearly, the hypothesis of evolution makes testable predictions with respect to the DNA sequences of clotting proteins, and these predictions have turned out to be correct time and time again.

Why has Behe's "Biochemical Challenge to Evolution" met with so little support within the scientific community? I would suggest that the reason is simple. His hypothesis is wrong. The complex biochemical systems of living organisms, including the vertebrate clotting cascade, are fully understandable in terms of Darwinian evolution.

Here's the total response Behe had to say about that...

Kenneth Miller, Brown University Professor of Biology and author of Finding Darwin's God, has posted a response to my essays: http://biocrs.biomed.brown.edu/Darwin/DI/Design.html Overall I'm satisfied with his reply because, although he continues to defend his position, from the substance of his writing I think it should be plain to most open-minded readers that he is struggling to fend off examples that weigh heavily against Darwinism. So, for the most part, I am content to let the exchange end here. I simply urge all who are interested to read my essays as well as his response and come to their own conclusions.

Behe did respond to other points Miller has made, but I haven't followed those so I don't know if he scored points or not. But as for the blood clotting cascade, Behe clearly has pleaded no contest.

59 posted on 12/31/2001 12:51:32 PM PST by jennyp
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To: Old Professer
Playing the Devil's Advocate here, I can set the environment for changing a solid into a liquid and then back again in my kitchen using simple plastic trays; isn't the keyword in this and all such experiments the reliance on a suitable chance environment for the natural world to be so explained?

Yes, but the question at issue is, "what's plausible in the natural world & what's not?" In an experiment you'd purposefully change the temperature up or down, but that's perfectly valid as long as temperatures go up & down in nature.

As for the bacteria, the question was, "where does the ability to survive in the face of antibiotics come from?" You can't answer this as definitively in the wild as you could in an isolated lab environment, since you could never be sure it was the test bacteria that evolved, nor could you be sure that some kind of lateral DNA transfer hadn't occurred from another species of bacteria, etc. That's why the lab experiment is so powerful.

60 posted on 12/31/2001 12:58:53 PM PST by jennyp
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