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2012年7月25日 星期三

The Limits of Ignorance 4

Cont'd

The chief scientific advocate of ID is Michael J Behe, a bio-chemist. He wrote a book called "Darwin's Black Box", (1996, 1998) ("DBB") to try to throw doubt about the validity of Darwin's theory of evolution by natural selection. As he says in chapter 1 of the book, his book is "about an idea--Darwinian evolution--that is pushed to the limits by discoveries in biochemistry" which to him, is "the study of the very basis of life: the molecules that make up cells and tissue, that catalyze the chemical reactions of digestions, photosynthesis, immunity and more." (DBB3) He says that "when foundations are unearthed, the structures that rest on them are shaken; sometimes, they collapse. When sciences such as physics finally uncovered their foundations, old ways of understanding the world had to be tossed out, extensively revised or restricted to a limited part of nature." (DBB 3) I have no quarrel with that. Then Behe asks, "Will this happen to the theory of evolution by natural selection?"

This is his understanding of Darwin's theory of evolution: "Like many great ideas, Darwin's is elegantly simple. He observed that there is variation in all species: some members are bigger, some smaller, some faster, some lighter in color, and so forth. He reasoned that since limited food supplies could not support all organisms that are born, the ones whose chance variation gave them an advantage in the struggle for life would tend to survive and reproduce, outcompeting the less favored ones. If the variations were inherited, then the characteristics of the species would change over time: over great periods, great changes might occur" (DBB 3-4) He notes that for more than a century, Darwin's idea has been used to explain finch beaks and horse hoofs, moth coloration and insect slaves and the distribution of life around the globe and through the ages. As far as I understand, Darwin bases his theory not only upon evidence of plants and animals but also evidence of geology, fossil records, biogeography, embryology, animal behavior, plant and animal breeding practices etc. No matter what, Behe says, s that evolutionary theory has been stretched by some scientists to explain why desperate people commit suicide, why teenagers have babies out of wedlock, why some groups do better on intelligence tests than other group and why religious missionaries forgo marriage and children. He claims: "there is nothing--no organ or idea, no sense or thought--that has not been the subject of evolutionary rumination".(DBB 4) His is a favourite argument technique( which goes by the name of "knocking down a strawman"): to exaggerate what appears to be "illegitimate extension" of a theory as a "good" reason to attack the "basic/core" idea of the relevant theory: thus causing the reader to confuse the "periphery" of the evolutionary theory with its "core" idea viz. how accidental variation of the genes of a species which give it a survival advantage over its rivals help to "preserve" such genetic characteristic of the species over long stretches of time.

Behe asks, "Can all of life be fit into Darwin's theory of evolution?" (DBB 5) The answer obviously is not. He claims, "The complexity 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" Then he makes a few disclaimers: "Many people think that questioning Darwinian evolution must be equivalent to espousing creationism...belief in the an earth formed only about ten thousand years ago, an interpretation of the Bible that is still very popular." (DBB 5) He dissociates himself from such a belief. "For the record, I have no reason to doubt that the universe is the billions of years old that the physicists say it is. Further I find the idea of common descent (that all organisms share a common ancestor) fairly convincing, and have no particular reason to doubt it...I think that evolutionary biologists have contributed enormously to our understanding of the world." (DBB 5) There we have it. My Christian friends who want to push ID should note that their "hero" does not dispute the basic accuracy of Darwin's evolutionary theory. So, what is ID all about? Behe says: "Although Darwin's mechanism--natural selection working on variation--might explain many things, however, I do not believe that it explains molecular life. I also do not think it surprising that the new science of the very small might change the way we view the less small." (DBB 5-6) The "black box" referred to in the title of his book is "molecular life" and " how life works". This is how he explains his "black box": " Black box is a whimsical term for a device that does something, but whose inner workings are mysterious--sometimes because the workings can't be seen, and sometimes because they just aren't comprehensible. Computers are a good example of a black box." (BDD 6) Behe says, "Biochemistry has pushed Darwin's theory to the limit. It has done so by opening the ultimate black box, the cell, thereby making possible our understanding of how life works. It is the astonishing complexity of subcellular organic structures that has forced the question. How could all this have evolved?" (DBB 15)This is something that he claims Darwin could not explain.

Is Behe right? Most certainly. But I must add two comments:
(1) Behe thinks that there are many gaps in the evolutionary theory. He uses the analogy of "jumps" in the theory. To him, " the word "jump" can be offered as an explanation of how someone crossed a barrier, but the explanation can range from completely convincing to totally inadequate depending on details such as how wide the barrier is. second. long journeys can be made much more plausible if they are explained as a series of smaller jumps rather than one great leap. And third, in the absence of evidence of such smaller jumps, it is very difficult to prove right or wrong someone who asserts that stepping stones existed in the past but have disappeared." (DBB 14) He says, "the word evolution has been invoked to explain tiny changes in organisms as well as huge changes. These are often given separate names: roughly speaking, microevolution describes changes that can be made in one or a few small jumps, whereas macroevolution describes changes that appear to require large jumps. The proposal by Darwin that even relatively tiny changes could occur in nature was a great conceptual advance....on a small scale, Darwin's theory has triumphed...But it is at the level of macroevolution--of large jumps--that the theory evokes skepticism. Many people have followed Darwin in proposing that huge changes can be broken down into plausible, small steps over great periods of time. Persuasive evidence to support that position, however, has not been forthcoming. ...With the advent of modern biochemistry, we are now able to look at the rock bottom level of life....Like a fractal pattern in mathematics, where a motif is repeated even as you look at smaller and smaller scales, unbridgeable chasms occur even at the tiniest levels of life." (DBB 15) To me, the fact that we have not yet been able to find evidence for ALL the "missing links" does not mean that we shall never find them. Our scientists are working hard to do so at this very moment. In fact, since Behe wrote his book, many new evidence of how animal's forelimbs may be turned into birds wings have been found.
(2) At the time Darwin proposed his theory i.e the mid-19th century, the biochemistry
which we now have simply did not exist. But science has since moved on.Many of the things about which Darwin had absolutely no idea about e.g.the structure of the DNA, the RNA and the data of the Human Genome Project and the kind of comparison we can make between human genes andthe genes of certain types of apes, were simply not available to Darwin.
So what is Behe complaining about? That Darwin lacked the foresight about the way genetic science could have advanced in the 20th century? And because Darwin's could not explain the details of the mechanism of the molecules of life, that his theory about evolution of the species must be rejected and thrown out? Yet he has admitted he had no problem with basics of Darwinian theory. If so, is all this hullabaloo about the teaching of ID in American high school "much ado about nothing"? He says, "On a small scale, Darwin's theory has triumphed...But it is at the level of macroevolution--of large jumps--that the theory evokes skepticism" (DBB 15) Here we must be careful about what he means by "micro" and "macro". "Macro" in the context of Behe's arguments means "big jumps" in observed structures of what we would normally call "micro" changes at the molecular level, and as he says, "at the tiniest levels of life", and NOT Darwin's evolutionary theory AS A WHOLE. His terminology is confusing IF people do not read him carefully. I do not know if that is deliberate because religious fanatics anxious to preserve what they take to be the "scientific" basis of their theory of the creation of the world based on the Bible may very well quote him "out of context" and take his skepticism about  "macroevolution" as meaning Darwin's theory of evolution "as a whole."

Behe explains what he is really after. "Now that the black box of vision has been opened, it is no longer enough for an evolutionary explanation of that power to consider only the anatomical structures of whole eyes, as Darwin did in the nineteenth century (and as popularisers of evolution continue to do today). Each of the anatomical steps and structures that Darwin thought were so simple actually involves staggeringly complicated bio-chemical processes that cannot be papered over with rhetoric....Thus biochemistry offers a Lilliputian challenge to Darwin. Anatomy is quite simply, irrelevant to the question of whether evolution could take place on the molecular level. So is the fossil record or whether the record is as continuous as that of US presidents. And if there are gaps, it does not matter whether they can be explained plausibly. The fossil record has nothing to tell us about whether the interactions of 11-cis retinal with rhodopsin, transducin and phosphodiesterase could have developed step by step. Neither do the patterns of biography matter, nor those of population biology, nor the traditional explanations of evolutionary theory for rudimentary organs or species abundance." He is careful not to go too far. He says, "This is not to say that random mutation is a myth or the Darwinism fails to explain anything (it explains micro-evolution very nicely) or that large scale phenomena like population genetics don't matter. They do. Until recently, however, evolutionary biologists could be unconcerned with the molecular details of life because so little was known about them. Now the black box of the cell has been opened, and the infinitesimal world that stands revealed must be explained."  This is the crux of the problem, to Behe. He is concerned that evolutionary biologist should explain  what we would normally call "micro" details of the evolution of a particular mechanism within the human eye ! I have no problems with that. Science should be based on evidence. I don't think the evolutionary theory should be an exception. But is this what the advocates of ID in the Dover School Board were concerned with, in their eagerness and in their own opinion righteously, to do the right thing by God i.e. to promote their Christianity under the guise of teaching high school kids "science" ? To say the least, that is dishonest, if not devious.  If it is devious, then they are devious, in the eyes of the ID advocates, for what they believe to be a noble cause, a higher cause, the cause of the God they worship. Does the end justify the means or vice versa?  Or should religious concern necessarily become scientific concerns? Is there any conflict between science and religion or if there is, should there be?

(To be cont'd)

2 則留言:

  1. Are ID advocates challenging evolution advocates on the evolution of the eye because of the scientific advances of the twentieth centuries?
    [版主回覆07/25/2012 14:51:33]I feel sorry for America: especially the lack of reflection on the part of its masses. They seem unwilling to budge from their set positions except where the expediency of "money" or power is involved.
    [pinkpanther501101回覆07/25/2012 14:28:30]This shows that how "foolish" the Americans are. Their involvement in the Middle East and antagonism with Islam have a lot to do with it. It may be the undoing of the Americans or even the whole world.
    [版主回覆07/25/2012 13:34:00]I think that they are trying to fight a rear guard battle against the theory of evolution because in their heart of hearts, they fear that the evolutionary theory may be right and if so, that would put a very heavy strain on their faith in the Bible as the "unerring word of God". To me, their efforts are misconceived. In fact, the very attempt to fight the ID battle on "scientific" ground betrays the "materialism" ( the very thing that religion is invented and is supposed to transcend) of their religious belief. They are betting on the wrong horse, so to speak. Their attempt to argue that because evolutionary scientists are not yet able to completely explain every tiny little evolutionary steps leading from one observation to the next in respect of what they call the "irreducible complexity" of life epitomised by the structure of the human eye, is just one step in a systemmatic and very carefully planned public relations exercise by the Discovery Institute who engineered the whole thing.This came out at the trial. A lot of money and careers are involved. There is more than "meet the eye", so to speak.

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  2. I have been following through this interesting debate. Eagerly awaiting the sequels.
    [版主回覆07/26/2012 07:09:59]There're still lots of material. Take your time.

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