Re: No free lunch theorems

Legacy route: /people/mgrey/IDC/200106080021.html Re: No free lunch theorems From: Wesley R. Elsberry < wre@cx33978-a.dt1.sdca.home.com > Newsgroups: talk.origins Date: 7 Jun 2001 19:10:29 -0400 Message-ID: <200106080021.RAA13020@CX33978-A.DT1.SDCA.HOME.COM> Subject: Re: No free lunch theorems In article <42YT6.14243$FS6.994617@NEWS6-WIN.SERVER.NTLWORLD.COM>, Dene Bebbington wrote: DB>Does anyone know whether the no free lunch theorems that DB>Dembski refers are applicable to evolutionary algorithms? Yes, they are. DB>Apparently evolutionary algorithms have been successfully DB>used to generate computer programs that solve real DB>problems. That would be genetic programming or evolutionary programming. There are a variety of categories of evolutionary computation; the production of programs is the topic of the above two mentioned classes, and also is prominent in "artificial life" simulations. Producing programs via evolutionary computation is a tough field, but some success (defined here as "working programs") has been had there. Other evolutionary computation has been applied to various optimization and search problems, with several successful applications (success defined here as "it found a reasonably good solution"). DB>It seems to me that if the result of such algorithms are CSI DB>then Dembski must be wrong. NFL says that when you average the performance of an algorithm over all "cost functions" of a problem, it performs no better on average than blind search. That is for *any* algorithm, not just evolutionary computation (which Dembski likes to imply). This goes to early claims that certain forms of evolutionary computation could be considered as general problem-solvers that could be deployed without much domain knowledge of a problem. NFL says that if you are concerned about the relative efficiency of getting a solution, you have to apply domain knowledge of the problem and cost function to select an algorithm with good performance on that problem and cost function. NFL isn't about essential capacity of an algorithm to produce a solution; it is about comparative efficiency of algorithms in producing solutions. It's my opinion that Dembski misconstrues or misunderstands what the NFL theorems say. I've passed word along that Dembski's choice of "No Free Lunch" for the title of a book that is due out this fall sets him up for embarrassment. That's still the title, so far as I know. It will be interesting to see how the reviews turn out. The introduction to the book is online at < http://www.idurc.org/nofreelunchintro.html >. Dembski's latest foray into invoking NFL can be seen at < http://www.metanexus.net/archives/message_fs.asp?ARCHIVEID=3294 >. It already has a couple of responses from Tom Schneider, which can be seen at < http://www.lecb.ncifcrf.gov/~toms/paper/ev/dembski/rebuttal.html > and < http://www.lecb.ncifcrf.gov/~toms/paper/ev/dembski/claimtest.html >. And don't forget my Dembski page at < http://inia.cls.org/~welsberr/ae/dembski_wa.html#sub_ea >. If anybody has a question that they think should be posed to Dr. Dembski, I'll be sharing the stage with him for a 90 minute workshop session on June 17th. Drop me email by the 13th, and maybe I'll get a chance to bring up your favorite topic. Time to get back to preparing figures for the dissertation... -- Wesley R. Elsberry, Student in Wildlife & Fisheries Sciences, Tx A&M U. Visit the Online Zoologists page ( http://www.rtis.com/nat/user/elsberry ) Co-recipient of "Most Obnoxious Critic" status awarded by William A. Dembski "It's not luck if you can do it consistently."-NB [ Other on-line articles ] [ ID-Commentaries ]


Legacy route: /people/mgrey/IDC/21340.html Re: Re[2]: [DebunkCreation] Any books on evolution? From: Morgan Grey < cynical_prophet@yahoo.com > To: < DebunkCreation@yahoogroups.com > Reply-to: < DebunkCreation@yahoogroups.com > Date: Sat Sep 8, 2001 12:10 pm Message: 21340 Subject : Re: Re[2]: [DebunkCreation] Any books on evolution? --- lflank@ij.net wrote: > On 7 Sep 01, at 12:17, Morgan Grey wrote: > > > I just discovered that my public library caries a > > copy of Dembski's $64.95 "The Design Inference". I > > suppose I know what I'm going to spend my weekend > > doing... > > Laughing uncontrollably . . . . . ? No, that is what I'm doing right now. Actually, I find much of what Dembski has to say genuinely interesting. Of course, it *is* his Ph.D. dissertion, so it better not be too silly. But this is propably because Dembski's design inference, as presented in TDI, is very different from how it is presented by most IDers, as well as by Dembski himself in popular books and articles. For one, Dembski doesn't claim that his filter can detect *ingelligent* design: "Although a design inference is often the occasion for inferring an intelligent agent (cf. the examples in the following sections), as a pattern of inference the design inference is not tied to any doctrine of intelligent agency. The design inference focuses on features of an event that bar it from being attributed to chance, not on the causal story underlying the event. To be sure, there is a connection between the design inference and intelligent agency (see Section 2.4). This connection, however, is not part of the logical structure of the design inference." (Dembski, W. A., 1998, "The Design Inference: Eliminating Chance Through Small Probabilities", pp. 8) In fact, Dembski defines "design" as "the set-theoretic complement of the disjunction regularity-or-chance" (pp. 36). Under this definition, I would have no problem with life being "designed", with the "designer" in part being the process of natural selection. ===== Morgan "Evolution is to the social sciences as statues are to birds: a convenient platform upon which to deposit badly digested ideas." (Steve Jones, 2000, "Darwin's Ghost", pp. xxvii) [ Other on-line articles ] [ ID-Commentaries ]


Legacy route: /people/mgrey/IDC/21397.html Re: Re[2]: [DebunkCreation] Any books on evolution? From: Morgan Grey < cynical_prophet@yahoo.com > To: < DebunkCreation@yahoogroups.com > Reply-to: < DebunkCreation@yahoogroups.com > Date: Mon Sep 10, 2001 9:58 am Message: 21397 Subject: Re: Re[2]: [DebunkCreation] Any books on evolution? --- Dave Oldridge < doldridg@s... > wrote: (snip) > And, while rigorously mathematical, that definition > [i.e. Dembski's] places all events that are produced > by a COMBINATION of regularity AND chance directly > under the heading of "designed." Thus all evolution > IS, by his definition, "design." > > Yet, he and others are quick to equivocate this > definition when they get et outside the academic, > mathematical environment. And such equivocation in > a trained mathematician is either gross incompetence > or a sin. Further equivocation on Dembski's part happens when someone challenges his claims with examples of genetic algorithm producing CSI. He has two similar tactics: Define "information" in such a way that it *by definition* cannot be produced by genetic algorithms. I'm at school, and doesn't have it handy, but in his "Intelligent Design", most of his discussion about natural selection as a "designer" consists of defining his way out of the issue. Of course, if "information" is defined so that it depends on how the structure in question came about, Dembski's "design inference" is useless, since it attempts to determine the "design" of something *without* knowing the causal story of the event in question. The other tactic is similar, and also depends on re-defining "design" in such a way that its status suddenly depends on its causal story. In < http://www.leaderu.com/offices/dembski/docs/bd-specified.html >, Dembski introduces a split between "appearant" and "actual CSI", and claims that "[j]ust as the Darwinian mechanism does not generate actual design but only its appearance, so too the Darwinian mechanism does not generate actual specified complexity but only its appearance." Of course, if something is CSI only if we know it to have not been generated by "the Darwinian mechanism", Dembski's claim that life contains CSI is no longer valid, since it is not known that life was not generated by "the Darwinian mechanism". Either way, his re-definition of terms used in TDI (or invention of terms not used there) while at the same time referring to TDI as "the book that supports all of this", makes me seriously suspicious of his integrity. ===== Morgan "Evolution is to the social sciences as statues are to birds: a convenient platform upon which to deposit badly digested ideas." (Steve Jones, 2000, "Darwin's Ghost", pp. xxvii) [ Other on-line articles ] [ ID-Commentaries ]


Legacy route: /people/mgrey/IDC/21990.html Dembski `retracts' comments about Dennett From: Morgan Grey < cynical_prophet@yahoo.com > To: < DebunkCreation@yahoogroups.com > Reply-to: < DebunkCreation@yahoogroups.com > Date: Sat Oct 20, 2001 8:04 pm Message: 21990 Subject: Dembski `retracts' comments about Dennett As readers of last week's ID-Commentary -"Disbelieving Darwin -- And Feeling No Shame!"- will remember, I took issue with Dembski's claim that Daniel Dennett "recommends 'quarantining' parents who teach their children to doubt Darwinism", arguing that Dembski was misrepresenting Dennett. I have just recieved an e-mail from Richard Wein, in which he, among other things, directs my attention to a "clarification" made by Dembski in a later post to Metanexus. As a sort of mini-ID-Commentary, here is Dembski's post, as well as my comments on it: ------------------------------------------------------- http://www.meta-list.org/archives/fulldetails.asp?listtype=Magazine&ARCHIVEID=2584 030: Disbelieving Darwin Discussed Metaviews 030. 2000.03.23. Approximately 2693 words. BG> William Dembski's previous posting on Metaviews BG> provoked lots of feedback. This Meta-post contains a number of short texts from various authors, as well as one by Dembski himself. However, I will only comment on the one posted by Dembski. [...] BG> Finally, William Dembski also writes with a BG> partial retraction of a statement made about BG> Daniel Dennett's reputed desire to "quarantine" BG> parents who doubt Darwinism. Note that even though Dembski himself refers to his posting as a "clarification" and never actually retracts anything, Bill Grassie refers to it as a "partial retraction" anyway. BG> Many other messages have also been exchanged on BG> this thread on the Reiterations Discussion List BG> and can be read at < http://www.meta-list.org > in BG> the archives. BG> BG> -- Billy Grassie [...] WAD> =-=-=-=-=-=-=-=-=-=-=-=-=-= From: "William A. WAD> Dembski" Subject: WAD> Clarification to "Disbelieving Darwin and Feeling WAD> No Shame" WAD> WAD> I'd like to post a clarification to my WAD> essay "Disbelieving Darwin and Feeling No Shame": WAD> WAD> In my essay "Disbelieving Darwin and Feeling No WAD> Shame" I made the following statement: "Daniel WAD> Dennett even recommends 'quarantining' parents WAD> who teach their children to doubt Darwinism (see WAD> the end of his *Darwin's Dangerous Idea*)." This WAD> is not quite accurate. On p. 519 of his book, WAD> Dennett states, "Those whose visions dictate that WAD> they cannot peacefully coexist with the rest of WAD> us we will have to quarantine as best we can...." WAD> A few lines later he continues, "If you insist on WAD> teaching your children falsehoods--that the Earth WAD> is flat, that "Man" is not a product of evolution WAD> by natural selection--then you must expect, at WAD> the very least, that those of us who have freedom WAD> of speech will feel free to describe your WAD> teachings as the spreading of falsehoods, and WAD> will attempt to demonstrate this to your children WAD> at our earliest opportunity. Our future well- WAD> being--the well-being of all of us on the planet-- WAD> depends on the education of our descendants." WAD> WAD> As Dennett in a private communication has made WAD> clear to me, he does not recommend quarantining WAD> parents who teach their children to doubt WAD> Darwin's theory and takes exception to anyone who WAD> attributes as much to him. I agree that there is WAD> no explicit recommendation here to quarantine WAD> parents who teach their children to doubt WAD> Darwinism. Nonetheless, it seems to me that there WAD> is an implicit recommendation to do just that. If WAD> (1) doubting Darwinian evolution is as silly as WAD> believing in a flat earth and (2) if our future WAD> well-being depends on the [proper] education of WAD> our descendants and (3) if "at the very least" WAD> Darwinists will attempt to demonstrate the truth WAD> of Darwinism to our children at their "earliest WAD> opportunity" and (4) if "quarantining" is WAD> maintained as a live option by Darwinists, then WAD> it is no big stretch to think that quarantining WAD> parents who teach their children to doubt Darwin WAD> is far from Dennett's intention. Dembski just repeats his original claim, adds some numbers, and wraps it up as a "clarification". In case Dembski is suffering from a reading disability, Dennett never advocates "quarantining" anyone on the basis of their ideas being "silly". Unless Dembski thinks that "teach[ing one's] children to doubt Darwin" "dictate that [one] cannot peacefully coexist with the rest of us", Dembski has absolutely nothing to be afraid of. WAD> Sincerely, Bill WAD> WAD> -- William A. Dembski, Ph.D. Director, Michael WAD> Polanyi Center Associate Research Professor in WAD> the Conceptual Foundations of Science Baylor WAD> University WAD> WAD> Address: William A. Dembski The Michael Polanyi WAD> Center P.O. Box 97130 Baylor University Waco, TX WAD> 76798-7130 WAD> WAD> E-mail: William_Dembski@baylor.edu Web: WAD> www.baylor.edu/~William_Dembski (personal) WAD> www.baylor.edu/~polanyi (Michael Polanyi Center) WAD> META> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Footer META> information below last updated: 1999/12/10. [...] META> Copyright 1999, 2000 by William Grassie. Copies META> of this internet posting may be made and META> distributed in whole without further permission. META> Credit: "This information was circulated on the META> Meta Lists on Science and Religion META> < http://www.meta-list.org >." ------------------------------------------------------- ===== Morgan "Creationists say--"Welcome to the war. We are eager to join battle, for we have the truth on our side, and the consequences are as important as life (eternal life) and death."" (Gish, D.T., 1993, "Creation Scientists Answer Their Critics", pp. 249) __________________________________________________ [ More ID-Commentaries ]


Who's Got the Magic?

Legacy route: /people/mgrey/IDC/2595.html Who's Got the Magic? 042: Who's Got the Magic? by William Dembski Metaviews 042. 2000.04.25. Approximately 2286 words. In the posting below, William Dembski from the Michael Polanyi Center at Baylor University offers a critical review of Robert Pennock's book "The Tower of Babel." In so doing, he argues again on behalf on "Intelligent Design Theory," which he distinguishes from "Creationism." In my view, the debate would be improved, if both terms were more carefully defined, rather than assumed. In any case, Dembski argues that the "something for nothing" thinking which characterizes scientific materialism approach to evolution is akin to "magic". "Pennock and his fellow scientific naturalists," writes Dembski, "are bargain hunters" (i.e. looking for something for nothing.) "They want to explain the appearance of design in nature without admitting actual design." Dembski and the Polanyi Center have been in the news recently with 1) a very ambitious conference on Naturalism in Science held two weeks ago involving a broad spectrum of thinkers, and 2) a recent vote by the faculty senate at Baylor University seeking to close the one-year old center (see the Chronicle of Higher Education on 4/19/00). I am grateful that these debates can also take place on Meta and welcome your comments and feedback. -- Billy Grassie =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= From: William_Dembski@baylor.edu (William A. Dembski) Subject: Who's Got the Magic? In criticizing Phillip Johnson's "intelligent design creationism," Robert Pennock raises a particularly worrisome legal consequence of Johnson's view. According to Pennock, Johnson insists "that science admit the reality of supernatural influences in the daily workings of the world." But what if the same reasoning that Johnson is trying to import into science were adopted in Johnson's own area of specialization -- the law (Johnson is a law professor at UC Berkeley)? Here's the concern as Pennock lays it out in _Tower of Babel_ (p. 295): [[indent]] "For the law to take [Johnson's view] seriously as well, it would have to be open to both suits and defenses based on a range of possible divine and occult interventions. Imagine the problems that would result if the courts had to accept legal theories of this sort. How would the court rule on whether to commit a purportedly insane person to a mental hospital for self-mutilation who claims that the Lord told her to pluck out her eye because it offended her? How would a judge deal with a defendant, Abe, accused of attempted murder of his son, Ike, who claims that he was only following God's command that he kill Ike to prove his faith?" Implicit in this passage and throughout Pennock's book is a forced choice between mechanism and magic: Either the world works by mechanisms that obey inviolable natural laws and that admit no break in the chain of natural causation, or all hell breaks loose and the world admits supernatural interventions that make a hash of science and our understanding of the world generally (and legal studies in particular). Pennock is offering his readers mechanism. Johnson is offering them magic. Any reasonable person knows which option to choose. But as with most forced choices, there's a tertium quid that Pennock has conveniently ignored, and that when properly understood shows that the real magician here is in fact Pennock and not Johnson. The tertium quid here is intelligent design, which is entirely separable from creationism. No doubt, Pennock's constant conjoining of the two serves a useful rhetorical purpose, rallying the troops, giving Darwinists a single common enemy, and keeping biology safe from teleology (indeed, it has become a point of grammatical correctness with Pennock never to use "intelligent design" without "creationism" -- "intelligent design" properly being an adjective that only modifies "creationism"). But Pennock, as a trained philosopher, knows that design is an old notion that requires neither miracles nor a creator (F. H. Sandbach's _The Stoics_, for instance, makes this abundantly clear). Intelligent design is detectable; we do in fact detect it; we have reliable methods for detecting it (cf. my _The Design Inference_); and its detection involves no recourse to the supernatural. Design is common, rational, and objectifiable. How, then, is Pennock a magician? There are at least three forms of magic. One is the art of illusion, where appearance is carefully crafted to distort reality. As entertainment, this form of magic is entirely unobjectionable. Another form of magic is to invoke the supernatural to explain a physical event. To call this magic is certainly a recent invention, since it makes most theists into magicians (Was Thomas Aquinas a magician for accepting as a historical fact the resurrection of Jesus? Was Moses Maimonides a magician for thinking that his namesake had parted the Red Sea?). According to Pennock, intelligent design creationism is guilty of this form of magic. Deep down, though, Pennock must realize that intelligent design (leaving off the creationism) can avoid this charge. Pennock is guilty of his own form of magic, however. The third form of magic, and the one Pennock and his fellow scientific naturalists are guilty of, is the view that something can be gotten for nothing. This third form of magic can be nuanced. The "nothing" here need not be an absolute nothing. And the transformation of nothing into something may involve minor expenditures of effort. For instance, the magician may need to utter "abracadabra" or "hocus-pocus." The Darwinian just-so stories that attempt to account for complex, information rich biological structures are likewise incantations that give the illusion of solving a problem but in fact merely cloak ignorance. The great appeal behind this third form of magic is the offer of a bargain -- indeed an incredible bargain for which no amount of creative accounting can ever square the books. The idea of getting something for nothing has come to pervade science. In cosmology, Alan Guth, Lee Smolin, and Peter Atkins all claim that this marvelous universe could originate from quite unmarvelous beginnings (a teaspoon of ordinary dust for Guth, black-hole formation for Smolin, and set-theoretic operations on the empty set for Atkins). In biology, Jacques Monod, Richard Dawkins, and Stuart Kauffman claim that the panoply of life can be explained in terms of quite simple mechanisms (chance and necessity for Monod, cumulative selection for Dawkins, and autocatalysis for Kauffman). We have become so accustomed to this something-for-nothing way of thinking that we no longer appreciate just how deeply magical it is. Consider, for instance, the following evolutionary account of neuroanatomy by Melvin Konner, an anthropologist and neurologist at Emory University: "Neuroanatomy in many species -- but especially in a brain-ridden one like ours -- is the product of sloppy, opportunistic half-billion year [evolution] that has pasted together, and only partly integrated, disparate organs that evolved in different animals, in different eras, and for very different purposes." (_IEEE Spectrum_, March 2000.) And since human consciousness and intelligence are said to derive from human neuroanatomy, it follows that these are themselves the product of a sloppy evolutionary process. But think what this means. How do we make sense of "sloppy," "pasted together," and "partly integrated," except with reference to "careful," "finely adapted," and "well integrated." To speak of hodge-podge structures presupposes that we have some concept of carefully designed structures. And of course we do. Humans have designed all sorts of engineering marvels, everything from Cray supercomputers to Gothic cathedrals. But that means, if we are to believe Melvin Konner, that a blind evolutionary process (i.e., Richard Dawkins's blind watchmaker) cobbled together human neuroanatomy, which in turn gave rise to human consciousness, which in turn produces artifacts like supercomputers, which in turn are not cobbled together at all but instead carefully designed. Out pop purpose, intelligence, and design from a process that started with no purpose, intelligence, or design. This is magic. Of course, to say this is magic is not to say it is false. It is after all a logical possibility that purpose, intelligence, and design emerge by purely mechanical means out of a physical universe initially devoid of these. Intelligence, for instance, may just be a survival tool given to us by an evolutionary process that places a premium on survival and that is itself not intelligently guided. The basic creative forces of nature might be devoid of intelligence. But if that is so, how can we know it? And if it is not so, how can we know that? It does no good simply to presuppose that purpose, intelligence, and design are emergent properties of a universe that otherwise is devoid of these. The debate whether nature has been front-loaded with purpose, intelligence, and design is not new. Certainly the ancient Epicureans and Stoics engaged in this debate. The Stoics argued for a design-first universe: the universe starts with design and any subsequent design results from the outworkings of that initial design (they resisted subsequent novel infusions of design). The Epicureans, on the other hand, argued for a design-last universe: the universe starts with no design and any subsequent design results from the interplay of chance and necessity. What is new, at least since the Enlightenment, is that it has become intellectually respectable to cast the design-first position as disreputable, superstitious, and irrational; and the design-last position as measured, parsimonious, and alone supremely rational. Indeed, the charge of magic is nowadays typically made against the design-first position, and not against the design-last position, as I have done here. But why should the design-first position elicit the charge of magic? Historically in the West, design has principally been connected with Judeo-Christian theism. The God of Judaism and Christianity is said to introduce design into the world by intervening in its causal structure. But such interventions cannot be anything but miraculous. And miracles is the stuff of magic. So goes the argument. The argument is flawed because there is no necessary connection between God introducing design into the world and God intervening in the world in the sense of violating its causal structure. Theists like Richard Swinburne, for instance, argue that God front-loads design into the universe by designing the very laws of nature. Paul Davies takes a similar line. Restricting design to structuring the laws of nature precludes design from violating those laws and thus violating nature's causal structure. Design easily resists the charge of magic. Rather, it's the a priori exclusion of design that has a much tougher time resisting it. Indeed, the design-last position is inherently magical. Consider the following remark by Harvard biologist Richard Lewontin in _The New York Review of Books_: [[indent]] "We take the side of science _in spite of_ the patent absurdity of some of its constructs, _in spite of_ its failure to fulfill many of its extravagant promises of health and life, _in spite of_ the tolerance of the scientific community for unsubstantiated just-so stories, because we have a prior commitment, a commitment to materialism. It is not that the methods and institutions of science somehow compel us to accept a material explanation of the phenomenal world, but, on the contrary, that we are forced by our _a priori_ adherence to material causes to create an apparatus of investigation and a set of concepts that produce material explanations, no matter how counterintuitive, no matter how mystifying to the uninitiated." If this isn't magic, what is? Even so, the scientific community continues to be skeptical of design. The worry is that design will give up on science. In place of a magic that derives something from nothing, design substitutes a designer who explains everything. Magic gets you something for nothing and thus offers a bargain. Design gets you something by presupposing something unimaginably bigger and thus asks you to sell your scientific soul. At least so the story goes. But design can be explanatory without giving away the store. Certainly this is the case for human artifacts, which are properly explained by reference to design. Nor does design explain everything: There's no reason to invoke design to explain a random inkblot; but a Dürer woodcut is something else altogether. The point of the intelligent design program is to extend design from the realm of human artifacts to the natural sciences. The program may ultimately fail, but it is only now being tried and it is certainly worth a try. Just as truth is not decided at the ballot box, so truth is not decided by the price one must pay for it. Bargains are all fine and well, and if you can get something for nothing, go for it. But there is an alternate tendency in science which says that you get what you pay for and that at the end of the day there has to be an accounting of the books. Some areas of science are open to bargain-hunting and some are not. Self-organizing complex systems, for instance, are a great place for scientific bargain-hunters to shop. Bernard cell convection, Belousov-Zhabotinsky reactions, and a host of other self-organizing systems offer complex organized structures apparently for free. But there are other areas of science that frown upon bargain-hunting. The conservation laws of physics, for instance, allow no bargains. The big question confronting design is whether it can be gotten on the cheap or must be paid for in kind. Design theorists argue that design admits no bargains. Pennock and his fellow scientific naturalists are bargain hunters. They want to explain the appearance of design in nature without admitting actual design. That's why Richard Dawkins begins _The Blind Watchmaker_ with "Biology is the study of complicated things that give the appearance of having been designed for a purpose," whereupon he requires an additional three hundred pages to show why it is only an appearance of design. Pennock and his fellow naturalists have my very best wishes for success in their hunt for the ultimate bargain. They may even be right. But they are not guaranteed to be right. And they certainly haven't demonstrated that they are right. They have yet to pull the rabbit out of the hat. William Dembski Baylor University =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Footer information below last updated: 1999/12/10. Meta is an edited and moderated listserver and news service dedicated to promoting the constructive engagement of science and religion. Subscriptions are free. For more information, including archives and submission guidelines, go to < http://www.meta-list.org >. There are now four separate meta-lists to which you can subscribe: is commentaries and bookreviews posted three to five times per week. is announcements and news and is posted as frequently as needed. is a monthly digest. is a higher volume discussion list which is lightly moderated. You can subscribe to one or all of the meta-lists. If you would like to unsubscribe or change your subscription options, simply go to < http://www.meta-list.org > and follow the links to subscribe or unsubscribe. Note that all subscription changes entered on the web forms, requires your confirmation by email. Copyright 1999, 2000 by William Grassie. Copies of this internet posting may be made and distributed in whole without further permission. Credit: "This information was circulated on the Meta Lists on Science and Religion < http://www.meta-list.org >."


Explaining Specified Complexity

Legacy route: /people/mgrey/IDC/3066.html Explaining Specified Complexity Meta 139: Dembski on "Explaining Specified Complexity" grassie@VOICENET.COM William Grassie Meta 139. 1999/09/13. Approximately 1883 words. Below is a column entitled "Explaining Specified Complexity" by William Dembski at Baylor University in Texas. Dembski discusses whether evolutionary algorithms can generate actual "specified complexity" in nature, as opposed to merely the appearances thereof (i.e., unspecified or randomly generated complexity). Dembski believes these problems in probability make plausible a concept of intelligence involved in evolution. Your comments are welcome on reiterations@meta-list.org . -- Billy Grassie =-=-=-=-=-=-=-=-=-=-=-=-=-=-=- EXPLAINING SPECIFIED COMPLEXITY William A. Dembski Michael Polanyi Center Baylor University Waco, Texas 76798 In his recent book The Fifth Miracle, Paul Davies suggests that any laws capable of explaining the origin of life must be radically different from scientific laws known to date. The problem, as he sees it, with currently known scientific laws, like the laws of chemistry and physics, is that they are not up to explaining the key feature of life that needs to be explained. That feature is specified complexity. Life is both complex and specified. The basic intuition here is straightforward. A single letter of the alphabet is specified without being complex (i.e., it conforms to an independently given pattern but is simple). A long sequence of random letters is complex without being specified (i.e., it requires a complicated instruction-set to characterize but conforms to no independently given pattern). A Shakespearean sonnet is both complex and specified. Now, as Davies rightly notes, contingency can explain complexity but not specification. For instance, the exact time sequence of radioactive emissions from a chunk of uranium will be contingent, complex, but not specified. On the other hand, as Davies also rightly notes, laws can explain specification but not complexity. For instance, the formation of a salt crystal follows well-defined laws, produces an independently known repetitive pattern, and is therefore specified; but that pattern will also be simple, not complex. The problem is to explain something like the genetic code, which is both complex and specified. As Davies puts it: "Living organisms are mysterious not for their complexity per se, but for their tightly specified complexity" (p. 112). How does the scientific community explain specified complexity? Usually via an evolutionary algorithm. By an evolutionary algorithm I mean any algorithm that generates contingency via some chance process and then sifts the so-generated contingency via some law-like process. The Darwinian mutation-selection mechanism, neural nets, and genetic algorithms all fall within this broad definition of evolutionary algorithms. Now the problem with invoking evolutionary algorithms to explain specified complexity at the origin of life is absence of any identifiable evolutionary algorithm that might account for it. Once life has started and self-replication has begun, the Darwinian mechanism is usually invoked to explain the specified complexity of living things. But what is the relevant evolutionary algorithm that drives chemical evolution? No convincing answer has been given to date. To be sure, one can hope that an evolutionary algorithm that generates specified complexity at the origin of life exists and remains to be discovered. Manfred Eigen, for instance, writes, "Our task is to find an algorithm, a natural law that leads to the origin of information," where by "information" I understand him to mean specified complexity. But if some evolutionary algorithm can be found to account for the origin of life, it would not be a radically new law in Davies's sense. Rather, it would be a special case of a known process. I submit that the problem of explaining specified complexity is even worse than Davies makes out in The Fifth Miracle. Not only have we yet to explain specified complexity at the origin of life, but evolutionary algorithms fail to explain it in the subsequent history of life as well. Given the growing popularity of evolutionary algorithms, such a claim may seem ill-conceived. But consider a well known example by Richard Dawkins (The Blind Watchmaker, pp. 47-48) in which he purports to show how a cumulative selection process acting on chance can generate specified complexity. He starts with the following target sequence, a putative instance of specified complexity: METHINKS*IT*IS*LIKE*A*WEASEL (he considers only capital Roman letters and spaces, here represented by bullets-thus 27 possibilities at each location in a symbol string). If we tried to attain this target sequence by pure chance (for example, by randomly shaking out scrabble pieces), the probability of getting it on the first try would be around 10 to the -40, and correspondingly it would take on average about 10 to the 40 tries to stand a better than even chance of getting it. Thus, if we depended on pure chance to attain this target sequence, we would in all likelihood be unsuccessful. As a problem for pure chance, attaining Dawkins's target sequence is an exercise in generating specified complexity, and it becomes clear that pure chance simply is not up to the task. But consider next Dawkins's reframing of the problem. In place of pure chance, he considers the following evolutionary algorithm: (i) Start out with a randomly selected sequence of 28 capital Roman letters and spaces, e.g., WDL*MNLT*DTJBKWIRZREZLMQCO*P (note that the length of Dawkins's target sequence, METHINKS*IT* IS*LIKE*A*WEASEL, comprises exactly 28 letters and spaces); (ii) randomly alter all the letters and spaces in this initial randomly-generated sequence; (iii) whenever an alteration happens to match a corresponding letter in the target sequence, leave it and randomly alter only those remaining letters that still differ from the target sequence. In very short order this algorithm converges to Dawkins's target sequence. In The Blind Watchmaker, Dawkins (p. 48) provides the following computer simulation of this algorithm: (1) WDL*MNLT*DTJBKWIRZREZLMQCO*P (2) WDLTMNLT*DTJBSWIRZREZLMQCO*P ... (10) MDLDMNLS*ITJISWHRZREZ*MECS*P ... (20) MELDINLS*IT*ISWPRKE*Z*WECSEL . .. (30) METHINGS*IT*ISWLIKE*B*WECSEL ... (40) METHINKS*IT*IS*LIKE*I*WEASEL ... (43) METHINKS*IT*IS*LIKE*A*WEASEL Thus, Dawkins's simulation converges on the target sequence in 43 steps. In place of 10 to the 40 tries on average for pure chance to generate the target sequence, it now takes on average only 40 tries to generate it via an evolutionary algorithm. Although Dawkins uses this example to illustrate the power of evolutionary algorithms, the example in fact illustrates the inability of evolutionary algorithms to generate specified complexity. We can see this by posing the following question: Given Dawkins's evolutionary algorithm, what besides the target sequence can this algorithm attain? Think of it this way. Dawkins's evolutionary algorithm is chugging along; what are the possible terminal points of this algorithm? Clearly, the algorithm is always going to converge on the target sequence (with probability 1 for that matter). An evolutionary algorithm acts as a probability amplifier. Whereas it would take pure chance on average 10 to the 40 tries to attain Dawkins's target sequence, his evolutionary algorithm on average gets it for you in the logarithm of that number, that is, on average in only 40 tries (and with virtual certainty in a few hundred tries). But a probability amplifier is also a complexity attenuator. For something to be complex, there must be many live possibilities that could take its place. Increasingly numerous live possibilities correspond to increasing improbability of any one of these possibilities. To illustrate the connection between complexity and probability, consider a combination lock. The more possible combinations of the lock, the more complex the mechanism and correspondingly the more improbable that the mechanism can be opened by chance. Complexity and probability therefore vary inversely: the greater the complexity, the smaller the probability. It follows that Dawkins's evolutionary algorithm, by vastly increasing the probability of getting the target sequence, vastly decreases the complexity inherent in that sequence. As the sole possibility that Dawkins's evolutionary algorithm can attain, the target sequence in fact has minimal complexity (i.e., the probability is 1 and the complexity, as measured by the usual information measure, is 0). In general, then, evolutionary algorithms generate not true complexity but only the appearance of complexity. And since they cannot generate complexity, they cannot generate specified complexity either. This conclusion may seem counterintuitive, especially given all the marvelous properties that evolutionary algorithms do possess. But the conclusion holds. What's more, it is consistent with the "no free lunch" (NFL) theorems of David Wolpert and William Macready, which place significant restrictions on the range of problems genetic algorithms can solve. The claim that evolutionary algorithms can only generate the appearance of specified complexity is reminiscent of a claim by Richard Dawkins. On the opening page of his The Blind Watchmaker he states, "Biology is the study of complicated things that give the appearance of having been designed for a purpose." Just as the Darwinian mechanism does not generate actual design but only its appearance, so too the Darwinian mechanism does not generate actual specified complexity but only its appearance. But this raises the obvious question, whether there might not be a fundamental connection between intelligence or design on the one hand and specified complexity on the other. In fact there is. There's only one known source for producing actual specified complexity, and that's intelligence. In every case where we know the causal history responsible for an instance of specified complexity, an intelligent agent was involved. Most human artifacts, from Shakespearean sonnets to Dürer woodcuts to Cray supercomputers, are specified and complex. For a signal from outer space to convince astronomers that extraterrestrial life is real, it too will have to be complex and specified, thus indicating that the extraterrestrial is not only alive but also intelligent (hence the search for extraterrestrial intelligence-SETI). Thus, to claim that laws, even radically new ones, can produce specified complexity is in my view to commit a category mistake. It is to attribute to laws something they are intrinsically incapable of delivering-indeed, all our evidence points to intelligence as the sole source for specified complexity. Even so, in arguing that evolutionary algorithms cannot generate specified complexity and in noting that specified complexity is reliably correlated with intelligence, I have not refuted Darwinism or denied the capacity of evolutionary algorithms to solve interesting problems. In the case of Darwinism, what I have established is that the Darwinian mechanism cannot generate actual specified complexity. What I have not established is that living things exhibit actual specified complexity. That is a separate question. Does Davies's original problem of finding radically new laws to generate specified complexity thus turn into the slightly modified problem of finding find radically new laws that generate apparent-but not actual-specified complexity in nature? If so, then the scientific community faces a logically prior question, namely, whether nature exhibits actual specified complexity. Only after we have confirmed that nature does not exhibit actual specified complexity can it be safe to dispense with design and focus all our attentions on natural laws and how they might explain the appearance of specified complexity in nature. Does nature exhibit actual specified complexity? This is the million dollar question. Michael Behe's notion of irreducible complexity is purported to be a case of actual specified complexity and to be exhibited in real biochemical systems (cf. his book Darwin's Black Box). If such systems are, as Behe claims, highly improbable and thus genuinely complex with respect to the Darwinian mechanism of mutation and natural selection and if they are specified in virtue of their highly specific function (Behe looks to such systems as the bacterial flagellum), then a door is reopened for design in science that has been closed for well over a century. Does nature exhibit actual specified complexity? The jury is still out. William A. Dembski =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Footer information below last updated: 1999/07/12. Meta is an edited and moderated listserver and news service dedicated to promoting the constructive engagement of science and religion. Subscriptions are free. For more information, including archives and submission guidelines, go to < http://www.meta-list.org >. There are now four separate meta-lists to which you can subscribe: [metaviews] is commentaries and bookreviews posted three to five times per week. [metanews] is announcements and news and is posted more frequently. [metamonthly] is a monthly digest. [reiterations] is a higher volume discussion list which is lightly moderated. You can subscribe to one or all of the meta-lists. If you would like to unsubscribe or change your subscription options, simply go to < http://www.meta-list.org > and follow the links to subscribe or unsubscribe. Note that all subscription changes entered on the web forms, requires your confirmation by email. Permission is granted to reproduce this e-mail and distribute it without restriction with the inclusion of the following credit line: This is another posting from the Meta-List < http://www.meta-list.org >. Copyright 1997, 1998, 1999. William Grassie. [ Other on-line articles ] [ ID-Commentaries ]


Dembski & the TSP

Legacy route: /people/mgrey/IDC/5f5blk.html Dembski & the TSP From: Wesley R. Elsberry < welsberr@orca.tamu.edu > Newsgroups: talk.origins,comp.ai.genetic Date: 1997/02/28 Message-ID: <5F5BLK$LC1@NEWS.TAMU.EDU>#1/1 Subject: Dembski & the TSP William Dembski gave a talk last Saturday at the "Naturalism, Theism, and the Scientific Enterprise" conference on intelligent design in general, and the results of his information theoretic analyses in particular. As expected, he claimed that functions, algorithms, chance, and natural laws were incapable of generating "complex specified information", whether considered seprately or in combination. I would like to thank everyone who sent me or posted possible questions for Dembski. I collated my own points of difference plus those into a handout which I had available that morning. Several of the points brought up in these newsgroups were also brought up in the discussion. Bill Jefferys asked about the proof that Dembski offered concerning gradualness of information acquisition under selection. I brought up genetic algorithms as an empirical disproof. In general, Dembski's response was to claim that his analysis was both general and sound, and therefore his questioners could not be correct. In discussion of my presentation the day before, Dembski had indicated that GAs find solutions to difficult problems because an intelligent programmer had made them. By reference to Dembski's own analysis, I took this to be a claim that the programmer had somehow infused information about the particular solution that a GA finds, and thus tainted the process. I asked Dembski about a specific case, a 500 city Traveling Salesman Problem. I asked where, precisely, the information about the particular tour found was introduced by the programmer. I eliminated the GA population handling routines, since those can be found in general toolkits applicable to many problems, not just 500 city TSPs. I eliminated the evaluation function, since by Dembski's own analysis, no function can produce information. Dembski responded that he objected to the notion that CSI can be gotten on the cheap or for free, and said that the information produced by a GA isn't untainted, since intelligence had to design the hardware, the operating system, the GA program itself, and the problem specification. I don't believe the response during the discussion to have been responsive to the point. Dembski's stated claim is that functions, algorithms, chance, and natural laws cannot *ever* produce CSI. Given an example of what by Dembski's standards is clearly CSI resulting from the application of a GA, what I'm told is that only algorithms which are made by an intelligence can produce CSI. This is a wholly different claim, and much weaker. The conference web site is http://www.dla.utexas.edu/depts/philosophy/faculty/koons/ntse/ntse.html -- Wesley R. Elsberry, 6070 Sea Isle, Galveston TX 77554. Central Neural System BBS, 409-737-5222, 1:385/385, ANNs, GAs, Alife, AI, evolution, and more. Student in Wildlife & Fisheries Sciences. http://www.rtis.com/nat/user/elsberry "shakespeare and i are frequently coarse" - archy [ Other on-line articles ] [ ID-Commentaries ]


Other On-line Articles

Legacy route: /people/mgrey/IDC/online.html Other On-line Articles These are some of the on-line articles I refer to in my ID-commentaries: Metaviews: Who's Got the Magic? (ARCHIVEID=2595) Disbelieving Darwin -- And Feeling No Shame! (ARCHIVEID=2581) Explaining Specified Complexity (ARCHIVEID=3066) Why Evolutionary Algorithms Cannot Generate Specified Complexity (ARCHIVEID=3080) Another Way to Detect Design? (ARCHIVEID=3097) Usenet: Dembski's Agency Triad (Message-ID: <199811261107.DAA21334@CX33978-A.DT1.SDCA.HOME.COM>#1/1) Dembski & the TSP (Message-ID: <5F5BLK$LC1@NEWS.TAMU.EDU>#1/1) Re: No free lunch theorems (Message-ID: <200106080021.RAA13020@CX33978-A.DT1.SDCA.HOME.COM>) Yahoo! Groups: Re: Re[2]: [DebunkCreation] Any books on evolution? (Message: 21397) Re: Re[2]: [DebunkCreation] Any books on evolution? (Message: 21340) [ Back to my ID-Commentaries ]


Who's the Real Fraud?

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Legacy route: /pages/wells/who-real-fraud_v2-3.html Who's the Real Fraud? Scientific mistakes, distortions, and sleights-of-hand in Wells' book Icons of Evolution by Nic Tamzek Copyright © 2002 [Draft Version 2.3, posted: February 17, 2002] Permission is given to copy and print this page for non-profit personal or educational use. Note: This document was written as a flier (!) for a Wells lecture at UCSD. This is an expanded web version, currently hosted at The Talk.Origins Archive: [ http://home.mmcable.com/faqs/wells ]. It is now a draft web article, and any constructive comments would be welcome (feel free to email me at the above address). A truly thorough refutation of Wells would take an entire book; however, any oversights in this version are the sole responsibility of the author and will be corrected in succeeding versions at the above URL. Contents Introduction A chapter-by-chapter critique of Icons of Evolution : Chapter 2: The Miller-Urey experiment Was there significant prebiotic oxygen? Was the prebiotic atmosphere reducing The RNA world Chapter 3: Darwin's Tree of Life Cambrian explosion Molecular phylogeny The root of the Tree of Life The Chinese paleontologist story Chapter 4: Homology in Vertebrate Limbs Is the definition of homology circular? Complexities of homology; R. A. Raff comments Chapter 5: Haeckel's Embryos More from R. A. Raff Richardson on creationists and Haeckel The vertebrate classes are not all equally related Chapter 6: Archaeopteryx -- The Missing Link Chapter 7: Peppered Moths The natural resting locations of peppered moths -- Majerus' data Peppered moth photographs, staged and otherwise What are the implications if moths rest most often underneath branches? The scientific literature Bruce Grant's review of Wells M.E.N. Majerus' review of Wells Of moths and maps Chapter 8: Darwin's Finches Chapter 9: Four-Winged Fruit Flies Chapter 10: Fossil Horses and Directed Evolution Chapter 11: From Ape to Human: The Ultimate Icon Conclusions What is Icons really about? Acknowledgements References Endnotes Introduction onathan Wells' book Icons of Evolution: Science or Myth? Why Much of What We Teach About Evolution Is Wrong (henceforth Icons ) makes a travesty of the notion of honest scholarship. Purporting to document that "students and the public are being systematically misinformed about the evidence for evolution," (p. XII) via common textbook topics such as peppered moths, embryo similarities, and fossil hominids [1] , Icons in fact contains a bevy of its own errors. This is not original -- creationists have been making mistakes about evolution for years. Newly and more insidiously, however, Icons contains numerous instances of unfair distortions of scientific opinion, generated by the pseudoscientific tactics of selective citation of scientists and evidence, quote-mining, and "argumentative sleight-of-hand," the last meaning Wells' tactic of padding his topical discussions with incessant, biased editorializing. Wells mixes these ingredients in with a few accurate (but always incomplete) bits of science and proceeds to string together (often in a logically arbitrary fashion) a narrative that is carefully crafted to make the semblance of an honest case for Wells' central defamatory accusation: that mainstream biologists are "dogmatic Darwinists that misrepresent the truth to keep themselves in power" (pp. 242-243). As is documented below, a picture of Wells' book Icons belongs in the dictionary next to the word "misrepresentation." The central pillar of Wells' case is this: "Some biologists are aware of difficulties with a particular icon because it distorts the evidence in their own field. When they read the scientific literature in their specialty, they can see that the icon is misleading or downright false. But they may feel that this is just an isolated problem, especially when they are assured that Darwin's theory is supported by overwhelming evidence from other fields. If they believe in the fundamental correctness of Darwinian evolution, they may set aside their misgivings about the particular icon they know something about." ( Icons , pp. 7-8) In other words, Wells argues that the specialists know about the problems in their field of expertise, but that everyone thinks that the evidence supporting evolution is somewhere else. This is just plain false, as we shall see -- the experts in each field have explicitly stated that the evidence in their field supports evolutionary theory. If Wells' above contention is false, then Wells' argument collapses. Wells likes asking questions; it is now time for him to answer some. Chapter 2: Miller-Urey experiment Prebiotic Oxygen. A key question in origin-of-life research is the oxidation state of the prebiotic atmosphere (the current best guess is that the origin of life occurred somewhere 4.0-3.7 bya (billion years ago)). Wells wants you to think that there is good evidence for significant amounts free oxygen in the prebiotic atmosphere (significant amounts of free oxygen make the atmosphere oxidizing and make Miller-Urey-type experiments fail). He spends several pages (14-19) on a pseudo-discussion of the oxygen issue, citing sources from the 1970's and writing that (p. 17) "the controversy has never been resolved", that "Evidence from early rocks has been inconclusive," and concluding that the current geological consensus -- that oxygen was merely a trace gas before approximately 2.5 bya and only began rising after this point -- was due to "Dogma [taking] the place of empirical evidence" (p. 18). None of this is true (see e.g. Copley, 2001 ). Certain minerals, such as uraninite, cannot form under significant exposure to oxygen. Thick deposits of these rocks are found in rocks older than 2.5 bya years ago, indicating that essentially no oxygen (only trace amounts) was present. On page 17 Wells notes that uraninite deposits have been found in more recent rocks, but neglects to mention to his readers that these only occur under rapid-burial conditions, whereas ancient deposits of uraninite occur in slow deposition conditions, for example in sediments laid down by rivers, so that the minerals were exposed to atmospheric gases for significant periods of time before burial. 'Red beds' are geologic features containing highly oxidized iron (rust) indicative of high amounts of oxygen. Wells (p. 17) notes that red beds are found before 2 bya, but fails to mention that the temporal limit of red beds is just a few hundred million years before 2 bya. Wells doesn't even mention the evidence that banded iron formations (incompletely oxidized iron indicative of ultralow-oxygen conditions) are very common prior to 2.3 bya and very rare afterwards. Wells also doesn't mention that early paleosols (fossil soils) from about ~2.5 bya contain unoxidized cerium, impossible in an oxygenic atmosphere (e.g., Murakami et al. , 2001 ). Finally, Wells doesn't mention to his readers that pyrite, a mineral even more vulnerable to oxidation than uraninite, is found unoxidized in pre-2.5 bya rocks, and with significant evidence of long surface exposure (i.e. grains weathered by water erosion; e.g. Rasmussen and Buick, 1999 ). Why does Wells leave out the converging independent lines of geological evidence pointing to an anoxic early (pre ~2.5 bya) atmosphere? Was the prebiotic atmosphere reducing? Are the Miller-Urey experiments "irrelevant"? The famous Miller-Urey experiments used a strongly reducing atmosphere to produce amino acids. Current geochemical opinion is that the prebiotic atmosphere was not so strongly reducing, but varies from moderately reducing to neutral. Completely neutral would be bad for Miller-Urey-type experiment, but even a weakly reducing atmosphere will produce lower but significant amounts of amino acids. In the approximately two brief pages of text where Wells actually discusses the reducing question (p. 20-22), Wells cites some more 1970's sources and then asserts that the irrelevance of the Miller-Urey experiment has become a "near-consensus among geochemists" (p. 21). This statement is misleading. What geochemists agree on is that if the early earth's mantle was of the same composition as the modern mantle and if only terrestrial volcanic sources are considered as contributing to the atmosphere, and if the temperature profile of the early atmosphere was the same as modern earth (this is relevant to rates of hydrogen escape) then there will be much less hydrogen compared to Miller's first atmosphere (20% total atm.). Even if this worst-case scenario is accepted, hydrogen will not be completely absent, in fact there is a long list of geochemists that consider hydrogen to be present (although in lower amounts, roughly 0.1-1% of the total atmosphere). At these levels of H 2 there is still significant (although much lower) amino acid production. Also, many geochemists think that these conditions do not represent the early earth, contrary to the impression given by Wells. For example, on p. 20, Wells mentions terrestrial volcanos emitting neutral gases (H 2 O, CO 2 , N 2 , and only trace H 2 ), but he fails to mention that mid-ocean ridge vents could have been significant sources of reduced gases -- they are important sources of reduced atmospheric gases even today, emitting about 1% methane ( Kasting and Brown, 1998 ) and producing reduced hydrogen and hydrogen sulfide (e.g. Kelley et al. , 2001 ; Perkins, 2001 ; Von Damm, 2001 ) and potentially ammonia prebiotically ( Brandes et al. , 1998 ; Chyba, 1998 ). Why does Wells exclude oceanic vents from consideration? Another strange omission is that Wells completely fails to mention the extraterrestrial evidence, which is the only direct evidence we have of the kinds of chemical reactions that might have occurred in early solar systems. For example he neglects to mention the famous Murchison meteorite, which contains mixtures of organic compounds much like those produced in Miller-Urey style experiments, and which constitutes direct evidence that just the right kind of prebiotic chemistry was occurring at least somewhere in the early solar system and that some of those products found their way to earth (see e.g. Engel and Macko, 2001 for a recent review). Wells asserts that since the 1970's, non-reducing atmospheres have become the "near-consensus." The latest article that Wells cites supporting this view, however, is a 1995 nontechnical news article in Science ( Cohen, 1995 ). Why doesn't he quote Kral et al. (1998) , who write, The standard theory for the origin of life postulates that life arose from an abiotically produced soup of organic material (e.g., Miller, 1953; Miller, 1992). The first organism would have therefore been a heterotroph deriving energy from this existing pool of nutrients. This theory for the origin of life is not without competitors (for a review of theories for the origins of life see Davis and McKay, 1996), but has received considerable support from laboratory experiments in which it has been demonstrated that biologically relevant organic materials can be easily synthesized from mildly reducing mixtures of gases (e.g., Chang et a l., 1983). The discovery of organics in comets (e.g., Kissel and Kruger, 1987), on Titan (e.g., >Sagan et al. , 1984), elsewhere in the outer solar system (e.g., Encrenaz, 1986), as well as in the interstellar medium (e.g., Irvine and Knacke, 1989) has further strengthened the notion that organic material was abundant prior to the origin of life. None of this is meant to convey the impression that no controversies exist (both Cohen (1995) and the Davis and McKay (1996) article cited by the above-quoted Kral et al. (1998) are about the various competing hypotheses about the origin of life). But textbooks generally mention some of these hypotheses (briefly of course, as there is only space for a page or two on this topic in an introductory textbook), and furthermore generally mention that the original atmosphere was likely more weakly reducing than the original Miller-Urey experiment hypothesized, but that many variations with mildly reducing conditions still produce satisfactory results. This is exactly what is written in the most popular college biology textbook, Campbell et al. 's (1999) Biology , for instance. In other words, the textbooks basically summarize what the recent literature is saying. The original Miller-Urey experiment, despite its limitations, is also repeatedly cited in modern scientific literature as a landmark experiment. So why does Wells have a problem with the textbooks following the literature? Wells wants textbooks to follow the experts, and it appears that they are. The RNA world. Wells writes (p. 22) as if the RNA world is an alternative to failed Miller-Urey-style experimentation. He cites no source for this claim, because the claim is pure obfuscation. The RNA world hypothesis is complementary, not opposed, to Miller-style prebiotic syntheses, as it is meant to explain how genetic replication got going without DNA, several steps down the road after prebiotic syntheses. Wells gives the impression that there are only two possible starts to life on earth, Urey-Miller style syntheses and the RNA world. Wells misleadingly cites several quotes that taken alone suggest that the RNA world is impossible, and that there is no remaining scientific explanations for life on earth. However, most authorities agree that the RNA world was one stage of the origin of life, rather than the very first stage, and that it was proceeded by a pre-RNA world. Indeed, the very authors he quotes to suggest that the RNA world is impossible go on to explain the concept of a pre-RNA world and how an RNA world would arise from that, but Wells omits all mention of this. Wells doesn't bother to cite recent work on precursors to the RNA world, see for example Cavalier-Smith (2001) for an introduction and references to ideas on this such as the 'NA world' and 'lipid world' (for the latter, see e.g. Segre et al. , 2001 ). Chapter 3: Darwin's Tree of Life Wells mixes up several issues in this chapter. As we saw in the previous chapter, he will give several topics each a cursory and incomplete treatment, raising doubts about each subject and connecting them together whether they are logically connected or not. The Cambrian Explosion . Here Wells is running down a path well-worn by his creationist and 'designist' (IDist) colleagues. As a result there is already significant literature available on the "animal phyla appeared suddenly, and without precursors, and all equally far apart from each other"-sort of contention. See for example Conway Morris ( Conway Morris, 1998 ) for an authoritative discussion, and Knoll and Carroll (1999) which is freely available online. A particularly interesting perspective is that of Keith B. Miller, geologist, evolutionist and evangelical Christian, who wrote an article (1999) in Perspectives on Science and Christian Faith entitled "The Precambrian to Cambrian Fossil Record and Transitional Forms," ( http://www.asa3.org/ASA/topics/evolution/PSCF12-97Miller.html ) in which he wrote, There is much confusion in the popularized literature about the evidence for macroevolutionary change in the fossil record. Unfortunately, the discussion of evolution within the Christian community has been greatly influenced by inaccurate presentations of the fossil data and of the methods of classification. Widely read critiques of evolution, such as Evolution: A Theory in Crisis by Denton, and Darwin on Trial by Johnson, contain serious misrepresentations of the available fossil evidence for macroevolutionary transitions and of the science of evolutionary paleontology. [...] The implication of much of the evangelical Christian commentary on macroevolution is that the major taxonomic groups of living things remain clearly distinct entities throughout their history, and were as morphologically distinct from each other at their first appearance as they are today. There is a clear interest in showing the history of life as discontinuous, and any suggestion of transition in the fossil record is met with great skepticism. The purpose of this short communication is to dispel some of these misconceptions about the nature and interpretation of the fossil record. On page 38 of Icons Wells quotes page 30 of Simon Conway Morris' (1998) book The Crucible of Creation about the "sharp demarcation" at the Cambrian explosion. But Conway Morris writes on the very next page (32-3), "The term 'explosion' should not be taken too literally, but in terms of evolution it is still very dramatic. What it means is the rapid diversification of animal life. 'Rapid' in this case means a few millions of years, rather than the tens or even hundreds of millions of years that are more typical when we consider evolution in the fossil record." And of course one of the central points of Conway Morris' entire book is that the morphological disparity that emerges in the Cambrian, often invoked by Wells & co. via quotation of people like Stephen J. Gould, is not quite as radical as the IDists or even Gould would have it. There is a significant problem in asserting that the animal phyla of the Cambrian are as morphologically diverse as the fauna today -- in large part this perception is due to the somewhat arbitrary concepts of 'phylum' and 'body plan'. Conway Morris writes (p. 170) that "the strangeness of the problematic Cambrian animals is really a human artifact, a construct of our imagination." On pages 185-195 he uses the fossils Wiwaxia and Halkieria as transitionals between phyla (which by Wells' account shouldn't exist) to connect three very 'disparate' major phyla -- Mollusca, Brachiopoda, and Annelida -- to each other. For someone who self-righteously passes judgment on figures in textbooks, Wells' figures are atrocious. His Figure 3.4, "Actual Fossil Records of the Major Living Animal Phyla" purports to show when the various animal phyla appear in the fossil record. Note that, again, Wells cites no source in his notes to figure out where his figures came from. However, examining a similar graphic at the online University of California Museum of Paleontology ( UCMP, 2000 ), we see that Wells has left a number of phyla out, namely the dozen or so that have either no fossil record or appear very late relative to the Cambrian phyla. Notably all of the missing phyla are soft-bodied, but if Wells admitted that numerous phyla existed without any fossil record whatsoever, he would severely weaken his argument on page 44 that any small, soft-bodied ancestors of the animal phyla would have been fossilized if they existed. Wells' figure also places Rotifera and Phoronida as having fossil records in the Cambrian, which could be correct if the UCMP page is out of date, but as Wells gives no references for the figure it is impossible to check. Molecular Phylogeny. Wells' second argument against the Tree of Life deals with the 'molecular clock' hypothesis -- namely that DNA or protein sequence divergence is regular enough to date ancient splits between lineages. This hypothesis is indeed being questioned by scientists, as the influence of things like natural selection may well alter the rate of sequence change (e.g. cone snail venoms are a fantastic example of rapid sequence divergence under selective pressure; see Espiritu et al. , 2001 ). And if these changes occur often enough then getting accurate clock dates, particularly for distant events, will be very hard. This is an entirely different thing from determining molecular phylogenies, however, which is what Wells is actually trying to debunk. But unfortunately for Wells, there is considerable evidence that these phylogenies are reliable and in reasonably good accord with phylogenies generated from other data. On the general subject of accuracy in molecular phylogenies see Theobald 2002b and for recent work on phyla evolution and metaz