living , each of which had a slightly more advanced version of an eye. Behe’s Jerry A. Coyne novelty was to extend this argument to complex biochemical pathways, the evo- The Great Mutator lution of many of which we do not yet fully understand. It was in the complexity of metabolism, blood clotting, and immu- The Edge of : this disclaimer is perfectly understand- nology that Behe claimed to have found The Search for the Limits able. For in this department resides Mi- the hand of the Great Designer. of chael Behe—that rara avis, a genuine The reviews of Darwin’s Black Box in By Michael J. Behe biologist who is also an advocate of “in- the were uniformly (, 320 pp., $28) telligent design.” And negative, for two reasons. First, we do does not wish to lose prospective stu- understand something about how these I. dents who bridle at the thought of study- pathways might have evolved in stepwise rowsing the websites of dif- ing miracles in their courses. fashion, though we are as yet admittedly ferent colleges, a prospective , or ID, is a modern ignorant of many details. (It is harder to student finds an un- form of cleverly constructed reconstruct the evolution of biochemi- usual statement on the page of to circumvent the many court decisions cal pathways than the evolution of or- the Department of Biological that have banned, on First Amendment ganisms themselves, because, unlike Sciences at Lehigh University. It begins: grounds, the teaching of religious views organisms, these pathways do not fos- B in the science classroom. ID has shed silize, and so their evolution must be re- The faculty in the department of many of the trappings that once cost constructed entirely from living species.) biological sciences is committed to the creationists scientific and legal credibil- Second, in the scientific community a highest standards of scientific integ- ity, including explicit reference to God failure to understand something does rity and academic function. This com- and the ludicrous idea that the Earth is not automatically count as evidence for mitment carries with it unwavering only about ten thousand years old. In- divine creation. Science is littered with support for academic freedom and the stead, God has been replaced by an un- once-mysterious facts first imputed to free exchange of ideas. It also demands specified “.” Besides God and later found out to be explicable the utmost respect for the scientific making the usual shopworn criticisms solely through natural processes. This, in method, integrity in the conduct of re- of evolutionary theory, IDers contend fact, is what Darwin’s theory of natural search, and recognition that the valid- that some features of life are too com- selection did to the earlier idea that or- ity of any scientific model comes only plex to have evolved, and so required ce- ganisms were designed by a Creator. as a result of rational hypothesis test- lestial intervention. More damaging than the scientific crit- ing, sound experimentation, and find- Behe has been an especially valuable icisms of Behe’s work was the review that ings that can be replicated by others. ally of the IDers. Not only is he one of he got in 2005 from Judge John E. Jones the few working scientists in their camp III. After an ID textbook called Of Pan- So far, so good. After all, every science (he is a protein ), thus giving das and People was proposed for biology department should adhere to rigorous them a smidgen of scientific respectabil- classes at a high school in Dover, Penn- canons of research. But then comes a ity, but in 1996 he published Darwin’s sylvania, a group of local parents brought curious disclaimer: Black Box, a popular-science book that suit against the Dover Area School Dis- has become something of a manifesto for trict and some of its members. There fol- The department faculty, then, are “intelligent design.” In that book, Behe up- lowed a six-week trial in federal court unequivocal in their support of evo- dated an old creationist chestnut: the as- in Harrisburg, , with the lutionary theory, which has its roots sertion that some aspects of life could not plaintiffs supported by the ACLU and a in the seminal work of Charles Darwin have evolved by means of natural selec- Pennsylvania law firm, and the school dis- and has been supported by findings tion, because that evolution would have trict defended by a right-wing Christian accumulated over 140 years. The sole required untenable steps. Consider the law firm. The case of Kitzmiller et al. v. dissenter from this position, Prof. eye, which consists of a number of inter- Dover Area School District et al., dubbed , is a well-known propo- acting parts (such as the retina, the optic by some “the Scopes trial of our cen- nent of “intelligent design.” While we nerve, the lens, and the cornea) that work tury,” included luminaries from both the respect Prof. Behe’s right to express together to allow vision. How could such scientific camp and the ID camp battling his views, they are his alone and are in a complex feature have evolved gradually it out in front of Judge Jones. With his sci- no way endorsed by the department. if it could not work unless all its com- entific credentials, Behe was the key wit- It is our collective position that intelli- ponents were already in place? Such ness for the defense. gent design has no basis in science, has features, said Behe, are “irreducibly com- Jones’s 139-page verdict for the plain- not been tested experimentally, and plex”: their evolution supposedly cannot tiffs was eloquent, strong, and unequivo- should not be regarded as scientific. be reduced to a sequential series of adap- cal, especially coming from a churchgoing tive steps, as required by Darwinian nat- Republican. He ruled that “intelligent de- To my knowledge, such a statement is ural selection. sign” is not only unscientific, but a doc- unique. Biology departments do not cus- Well, scientists already knew that “irre- trine based firmly on religion. Jones called tomarily assert publicly that they support ducibly complex” features can indeed be the introduction of the clandestinely cre- a theory known for more than a century explained by ; and Dar- to be true. This is equivalent to a chem- win himself had no trouble doing this for Jerry A. Coyne is a professor in the depart- istry faculty announcing that “we are un- the eye in On the Origin of Species, de- ment of ecology and evolution at the Uni- equivocal in our support of atoms.” Yet scribing a series of perfectly well-adapted versity of Chicago.

38 June 18, 2007 ationist textbook at Dover High School biology accepted, what’s left for a good n the basis of much evidence, an act of “breathtaking inanity.” He also IDer to contest? Behe finds his bugbear scientists have concluded that found Behe’s testimony wholly uncon- in evolutionary theory’s view that “ran- occur randomly. The vincing, noting that irreducible complex- dom ” provides the raw material Oterm “random” here has a specific mean- ity was not evidence against evolution, for evolutionary change. And to under- ing that is often misunderstood, even by and that the biochemical systems touted stand his critique, we first have to grasp biologists. What we mean is that muta- by Behe were not irreducibly complex how mutation fits into evolutionary the- tions occur irrespective of whether they anyway. Behe’s credibility was damaged ory, and what scientists mean when they would be useful to the organism. Mu- also by his admission that ID’s definition say that mutations are “random.” tations are simply errors in DNA rep- of science was so loose that it could en- If evolution is a car, then natural se- lication. Most of them are harmful or compass , and by his fatal asser- lection is the engine and mutation is the neutral, but a few of them can turn out tion that the plausibility of the argument gas. Although evolutionary change can to be useful. And there is no known bi- for ID depends upon the extent to which be driven by several processes, natural ological mechanism for jacking up the one believes in the . selection is almost certainly the main probability that a mutation will meet the But IDers, like all creationists, are one—and the only one that can adapt current adaptive needs of the organism. never down for the count, because they organisms to their environment, creat- Bears adapting to snowy terrain will not see themselves as fighting for the Lord. ing the misleading appearance of delib- enjoy a higher probability of getting mu- So Behe is back now, with a new book erate design. Yet natural selection, which tations producing lighter coats than will and a brand-new theory that puts the is simply the preservation of genes that bears inhabiting non-snowy terrain. Intelligent Designer back into biology. give their possessors greater reproduc- What we do not mean by “random” What has Behe now found to resurrect tive success than their competitors, can- is that all genes are equally likely to his campaign for ID? It’s rather pathetic, not take place without genetic variation. mutate (some are more mutable than really. Basically, he now admits that al- Although Darwin had no idea where this others) or that all mutations are equally most the entire edifice of evolutionary variation came from, we now know that likely (some types of DNA change are theory is true: evolution, natural selec- it is produced by mutation—acciden- more common than others). It is more tion, common ancestry. His one novel tal changes in the sequence of DNA that accurate, then, to call mutations “indif- claim is that the genetic variation that usually occur as copying errors when a ferent” rather than “random”: the chance fuels natural selection—mutation—is molecule replicates during division. of a mutation happening is indifferent to produced not by random changes in We also know that mutation-generated whether it would be helpful or harmful. DNA, as evolutionists maintain, but by variation is pervasive: different forms of Evolution by selection, then, is a com- an Intelligent Designer. That is, he sees genes produced by mutation, for exam- bination of two steps: a “random” (or God as the Great Mutator. ple, explain variation in human eye color, indifferent) step—mutation—that gen- blood types, and much of our—and other erates a panoply of genetic variants, both II. species’—variation in height, weight, bio- good and bad (in our example, a vari- or a start, let us be clear about chemistry, and innumerable other traits. ety of new coat colors); and then a de- what Behe now accepts about evo- Once the variation exists, those genes terministic step—natural selection—that lutionary theory. He has no prob- that enhance an individual’s “fitness” are orders this variation, keeping the good Flem with a 4.5-billion-year-old Earth, preserved, and those that reduce it are and winnowing the bad (the retention of nor with evolutionary change over time, discarded. (Natural selection is not re- light-color genes at the expense of dark- nor apparently with its ample documen- ally a “process,” but simply a description color ones). tation through the fossil record—the of the differential and adaptive survival It is important to clarify these two geographical distribution of organisms, of genes.) The polar bear, for instance, steps because of the widespread mis- the existence of vestigial traits testify- has a white coat (its hairs actually lack conception, promoted by creationists, ing to ancient ancestry, and the finding pigment but appear white because that in evolution “everything happens by of fossil “missing links” that show com- they reflect light), and since this color chance.” Creationists equate the chance mon ancestry among major groups of is unique among bears, the polar bear that evolution could produce a complex organisms. Behe admits that most evo- presumably evolved from a dark-furred organism to the infinitesimal chance lution is caused by natural selection, and ancestor. The likely scenario is that mu- that a hurricane could sweep through that all species share common ancestors. tations occurred that produced individu- a junkyard and randomly assemble the He even accepts the one fact that most als varying in their coat color. Bears with junk into a Boeing 747. But this analogy other IDers would rather die than admit: a lighter coat had an advantage over oth- is specious. Evolution is manifestly not that humans shared a common ancestor ers, for they would be more camouflaged a chance process because of the order with chimpanzees and other apes. against the Arctic ice and snow and bet- produced by natural selection—order Why does Behe come clean about all ter at sneaking up on seals. Lighter bears that can, over vast periods of time, re- this? The reason is plain. would then outcompete sult in complex organisms looking as There is simply too much darker ones at getting if they were designed to fit their envi- evidence for any scientist food and thus produce ronment. Humans, the product of non- to deny these facts without more offspring, leaving random natural selection, are the biolog- losing all credibility. “Intel- more copies of the “light- ical equivalent of a 747, and in some ways ligent design” is desperate coat” genes. Over time, they are even more complex. The expla-

a for scientific respectability, the population of bears nation of seeming design by solely mate- and you do not get that by would evolve lighter and rialistic processes was Darwin’s greatest fighting facts about which lighter coats until they achievement, and a major source of dis- everybody agrees. But were almost invisible comfort for those holding the view that t Walen Tomasz with most of evolutionary against the snow. was designed by God.

The New Republic June 18, 2007 39 III. population, ensuring some protection ful anti-viral drugs. Again he sees little n a series of rather disconnected against but also the continuing evolution of complexity: “HIV has killed and scientifically dubious arguments, production of babies with sickle-cell ane- millions of people, fended off the human Behe tries to claim that random mu- mia. Africans would be better off if ev- , and become resistant to Itations cannot possibly be the building eryone were a heterozygote, but that is whatever drug humanity could throw at blocks of evolution. His main argument impossible, because the two gene copies it. Yet through all that, there have been involves malaria, in particular the evo- separate at reproduction and unite with no significant basic biochemical changes lution of humans to resist infection by other copies, necessarily producing some in the virus at all.” malaria, and the evolution of the malaria deleterious homozygotes. In light of evolutionary theory, these parasite itself to counteract the evolu- This example shows that natural selec- conclusions are truly bizarre. No sane tion of human resistance and the devel- tion does not necessarily produce abso- evolutionist has ever claimed that an ad- opment of anti-malarial drugs. lute perfection; it works with whatever aptation of a parasite to a host will pro- Malaria actually provides a superb ex- mutations arise to create the best possi- duce complex biochemical changes. ample of natural selection, and its story ble situation given the available raw ma- Evolutionary theory predicts only that has some intriguing quirks. The dis- terial and the constraints of genetics. And parasites will adapt, not how they will ease is caused by a protozoan carried by finally, although the malaria parasite has adapt. In fact, both the malaria parasite mosquitoes, who act as flying syringes been unable to counter-evolve resistance and the HIV virus have undergone suffi- that inject the microbe into the human to heterozygotes for the sickle-cell gene, cient “biochemical change” to make them bloodstream. There it takes up residence it has evolved, through mutation, resis- almost completely adapted to withstand in the liver and then in the red blood tance to various anti-malarial drugs de- both human drugs and the immune sys- cells, multiplies prolifically, and can ul- vised by humans. This resistance has tem. And humans have, through the timately cause anemia, kidney failure, become so strong that some strains sickle-cell mutation and other changes hemorrhage, and death. Residence in red of malaria are completely resistant to in , become somewhat re- blood cells and the liver is adaptive for drugs—yet another example of success- sistant to malaria. Beyond that, what the parasites, because in those spots they ful natural selection. does Behe expect? A red blood cell with are hidden from the immune system that hands to throttle the parasite? A malaria usually destroys invading microbes. Yet alaria, then, shows evo- parasite with a cunning brain to outwit the human spleen can also detect and de- lution acting on a number of the sickle-cell protein? HIV and malaria stroy circulating parasite-laden cells. To levels. So how can it disprove are doing pretty well at reproducing them- counter this tactic, the malaria parasite MDarwinian evolution? According to Behe, selves—sans new complex systems—in secretes proteins that cause its carrier malaria shows that random mutation their present environments. That is all blood cells to stick to the walls of blood is insufficient to explain biological evolution can do. vessels, avoiding the spleen (this sticking complexity. He disparages the defensive So what if the malaria parasite has not is what causes hemorrhage). sickle-cell mutation and similar muta- completely outwitted the sickle-cell mu- Here, then, is an arms race between tions, saying that they “are quintessen- tation? No biologist, least among them a blood-loving parasite and a human tially hurtful mutations because they Darwin, ever claimed that adaptation is body seeking to destroy it. Yet the story diminish the functioning of the human always perfect. Every infection by a para- is even more complicated and interest- body” (does successfully resisting ma- site, every disease, and every species that ing. In sub-Saharan Africa, where ma- laria really diminish the function of our goes extinct represents a failure to adapt. laria is rampant, a mutation has arisen body?) and that they are “not in the pro- Sometimes the right mutations do not in the gene producing hemoglobin that cess of joining to build a complex, inter- arise or cannot arise because of the con- helps ward off malaria. The striking thing active biochemical system.” And although straints of development; sometimes they about this mutation, known as the sickle- the parasite and the humans are in the do arise, but produce an imperfect adap- cell mutation, is that it somehow reduces process of trying to outwit each other in tation. In his book The Causes of Evolu- the chances of contracting malaria when an evolutionary arms race (including the tion, the British biologist J. B. S. Haldane its carriers have one copy of the gene (like development of drugs), Behe notes that addressed this problem with tongue in most organisms, we have two copies of this arms race has not prompted the evo- cheek: “A selector of sufficient knowledge every gene, one on each of our two sets lution of biological complexity. Instead and power might perhaps obtain from the of chromosomes), but it causes sickle-cell Behe sees the malaria/parasite battle as genes at present available in the human anemia when the carriers have two cop- a mere “trench war of attrition.” species a race combining an average intel- ies. In sickle-cell anemia, the red blood In the end, after pages of rather tedious lect equal to that of Shakespeare with the cells form clumps because of the altered detail about malaria, Behe dismisses the stature of Carnera. But he could not pro- hemoglobin they carry, causing a syn- evolutionary aspects of malaria as “cha- duce a race of angels. For the moral char- drome of complications that invariably otic and tangled,” which, while showing acter or for the wings, he would have to cause death before adulthood. random mutation and natural selection, await or produce suitable mutations.” Thus we have the unusual situation in are irrelevant to his main concerns: “In By disparaging the malaria system as which heterozygotes, or individuals car- this book we are concerned with how mere “” and characterizing rying both one “normal” and one “mutant” machinery [i.e., complex organisms] can the mutations involved as “not construc- hemoglobin gene, are fitter than homozy- be built,” he writes. “To build a complex tive” and causing “broken genes,” Behe gous individuals, who carry either two machine many different pieces have to not only engages in sophistry, but shows “normal” genes (more susceptible to ma- be brought together and fitted to one an- an almost willful misunderstanding of laria) or two mutant genes (death from other.” Behe buttresses his conclusion by Darwinism. Natural selection is not a sickle-cell anemia). Evolutionary genet- describing how the AIDS virus evolved one-way path to more complex adapta- ics tells us that in a case such as this one, to outwit not only the strategies of the tions or organisms. Organisms adapt to both forms of the gene will remain in the human immune system but also power- whatever environmental challenges they

40 June 18, 2007 The New Republic face, and those changes could require ei- tem is—to see how different it is from ther small biochemical adjustments (as the broken genes and desperate mea- in the case of malaria), more extensive sures that random mutation routinely changes that require complex adapta- involves.” (“Broken genes and desper- tion (as in the evolution of amphibians ate measures” refers to the simple ad- from fish), or even the evolution of less aptations of the malaria parasite and its complexity. The tapeworm, for example, human opponent.) Surely, says Behe, a is considerably simpler than its ancestor: better theory is that cilia were created it has lost its nervous system, its diges- by the Intelligent Designer. tive system, and most of its reproductive In Darwin’s Black Box, Behe made ex- system, becoming in effect an absorp- actly the same argument to show that a tive sack of gonads. But it is nevertheless similar structure, the (a larger well adapted to its novel intestinal niche, cilium that propels microorganisms), where it can dispense with unnecessary could not have evolved by natural selec- features (its food, for one thing, is pre- tion. But in this case Behe’s claim that digested). Using malaria and HIV to no intermediate stages could have ex- argue that random mutations cannot fuel isted was refuted. Ken Miller, a biologist the evolution of complexity is like dis- at Brown University (and an observant playing a crudely built footstool to prove Catholic), showed how flagella and cilia that it is impossible to build a house with could have had their precursors in mech- lumber, hammer, and nails. anisms that the cell uses to transport pro- teins, mechanisms that are co-opted to IV. construct flagella. Indeed, the whole he general reader, at whom problem of the evolution of cilia was ar- is aimed, is gued before Judge Jones in Harrisburg, unlikely to find the scientific holes who ruled that there was no convincing Tin its arguments. Behe writes clearly and evidence that evolution could not have engagingly, and someone lacking formal produced this structure, making legal training in and evolution- doctrine from something biologists al- ary biology may be easily snowed by his ready knew. In his new book, however, rhetoric. The snow falls most heavily when Behe simply ignores his critics, repeat- Behe writes about the complex biochem- ing his bankrupt claim that there is “no ical adaptations of animals, such as the Darwinian explanation for the step-by- structure and the operation of cilia. Cilia step origin of the cilium.” are small, hairlike structures whose rhyth- If ID were science, we could make an mic beating propels microorganisms; they equivalent demand of its advocates. We also help move things along in other spe- could ask Behe to produce a complete cies (cilia line the fallopian tubes of mam- step-by-step accounting of what God mals, for example, where they sweep the (sorry, the Intelligent Designer) did when egg into the uterus). Each cilium is built He designed the cilia. And of course Behe from more than two hundred different would not be able to do that—nor does he proteins, including those making up its even try. IDers never produce their own structure and “motor proteins” that make “scientific” explanation of life. They just it move. Moreover, when a cilium is dam- carp about evolution. And as evolution- aged or a new one is built, an equally com- ists explain one thing after another, IDers plex system of intraflagellar transport uses simply ignore these successes and move sixteen other proteins to bring new mate- on to the ever-dwindling set of unsolved rial from out of the cell for repair, rather problems in which they continue to see like a molecular assembly line. the hand of God. This description is entertaining and Behe’s arguments from the gaps in sci- instructive, and those unacquainted entific knowledge are fatuous. It is cer- with molecular biology will be wowed tainly true that we do not yet understand by the elegance of this adaptation. In- every step in the origin of the cilium, but deed, such complex features were what these are early days. Molecular biology lured many of us into biology, hoping is a very young field, and molecular evo- to explain their evolution. But the pur- lutionary biology is even younger. The pose of Behe’s exercise, beyond peda- way to understand the evolution of cilia gogy, is simply to overwhelm the reader is to get to work in the laboratory, not with nature’s complexity, hoping to raise to throw up our hands and cry “design.” the question of how mutation and nat- Perhaps we will never understand every ural selection could possibly have built step in the evolution of a complex feature, such a feature—as if being wowed were just as we cannot know everything about the same as being persuaded. As Behe the development of human civilization says, “The point is to see how elegant from archaeology. But is the incomplete- and interdependent the coherent sys- ness of our knowledge a reason to invoke

The New Republic June 18, 2007 41 God? The history of science shows us amino acids required for only one protein- step), and so on until all twenty dice show that patching the gaps in our knowledge protein interaction is very low (mutations a six. On average, this would take about with miracles creates a path that leads in the DNA affect the building blocks of a hundred and twenty rolls, or a total of only to perpetual ignorance. proteins, since DNA codes for a sequence two minutes at one roll per second. This of amino acids). It is especially low be- sequential way of getting twenty sixes is V. cause Behe requires all of the three or four infinitely faster than Behe’s method. And eyond his own incredulity, Behe mutations needed to create such an inter- this is the way natural selection and mu- has two other arguments against action to arise simultaneously. Since any tation really work, not by the ludicrous the efficacy of mutation and natural one mutation is very rare (on the order of scenario presented by Behe. Bselection in creating complex features: one in a billion in any given generation at As for Behe’s assertion that mutation a specified DNA site), the chances that a and selection cannot produce “coher- First, steps. The more intermediate specified group of changes could arise in ence,” it is absurd. Coherence is precisely evolutionary steps that must be one fell swoop is unimaginably rare. And the product of natural selection working climbed to achieve some biological this is for only a single pair of interacting with mutation. Yes, mutations are ran- goal without reaping a net benefit, the proteins. When you consider the thou- dom in the sense I have described, but to more unlikely a Darwinian explanation. sands of proteins in a cell that interact say that an evolutionary step taken by an Second, coherence. A telltale signature with others, some with as many as five or organism is unconnected to its predeces- of planning is the coherent ordering of six others, evolution looks impossible. sor completely ignores the fact that dur- steps toward a goal. Random mutation, Wrong. If it looks impossible, this is ing evolution organisms are adapting to on the other hand, is incoherent; that is, only because of Behe’s bizarre and un- something in their environment, and that any given evolutionary step taken by a realistic assumption that for a protein- this adaptation can involve a coherent, population of organisms is unlikely to protein interaction to evolve, all muta- coordinated response of many features. be connected to its predecessor. tions must occur simultaneously, because Consider the evolution of whales from the step-by-step path is not adaptive. Yet terrestrial animals, now documented by These arguments betray a profound, al- Behe furnishes no proof, no convincing a superb fossil record. The fossils show most willful ignorance of the evolution- argument, that interactions cannot evolve a wolf-like creature gradually becom- ary process. It is indeed true that natural gradually. In fact, interactions between ing aquatic, with the hind limbs being selection cannot build any feature in proteins, like any complex interaction, reduced and finally lost, the forelimbs which intermediate steps do not confer were certainly built up step by mutational transformed into flippers, and the nos- a net benefit on the organism. As Darwin step, with each change producing an trils gradually moving atop the head to wrote in On the Origin of Species, “If it interaction scrutinized by selection and form the blowhole. How can anyone say could be demonstrated that any complex retained if it enhanced an organism’s fitness. that these changes (which of course look organ existed, which could not possibly This process could have begun with weak planned at the end) are unconnected or have been formed by numerous, suc- protein-protein associations that were incoherent? They represent a case of nat- cessive, slight modifications, my theory beneficial to the organism. These were ural selection eventually turning a land would absolutely break down. But I can then strengthened gradually, involving animal into a well-adapted aquatic one. find out no such case.” A century and a more and more amino acids to make the Not surprisingly, Behe ignores the fact half later, there is still no such case. Behe interaction stronger and more specific. At the evolutionists have indeed determined certainly fails to make one. the end, you get what we see today: many whether mutations are random. Instead, But he does try gamely, claiming that proteins interacting strongly and specifi- he asserts that randomness is simply as- complex interactions between proteins cally. What seems improbable in a single sumed by biologists because “the domi- are features that simply could not have leap becomes much more likely when it nant theory [evolution] requires it.” That evolved. Proteins represent strings of evolves gradually, step by step. is, all evolutionists are dupes. But for building blocks—amino acids—and the A simple example shows this difference. several decades molecular biologists cooperation between some proteins re- Suppose a complex adaptation involves have tested in the laboratory Behe’s as- quires that sets of amino acids in one twenty parts, represented by twenty dice, sumption of non-randomness: that the protein interact rather precisely with each one showing a six. The adaptation is probability of a mutation being useful sets in another. (For example, the two fueled by random mutation, represented increases when a species is exposed to strings of amino acids making up human by throwing the dice. Behe’s way of get- a new environment. These experiments hemoglobin, the alpha and beta chains, ting this adaptation requires you to roll have all failed. As far as we can see, mu- are closely aligned, and work together all twenty dice simultaneously, waiting tations really are random with respect to in a coordinated way to take aboard ox- until they all come up six (that is, all suc- the “needs” of the organism. There is no ygen and later relinquish it in the right cessful mutations must happen together). reason to assume otherwise. tissues.) Such precise protein-protein The probability of getting this outcome To get an idea of the power of truly ran- interactions, says Behe, could not have is very low; in fact, if you tossed the dice dom mutations coupled with selection, been formed by “numerous, successive, once per second, it would take about a we need only look at the successes of an- slight steps,” because such Darwinian hundred million years to get the right imal and plant breeders over the past few evolution would be wildly improbable. outcome. But now let us build the adap- centuries. In that time, they have turned To demonstrate the improbability, Behe tation step by step, as evolutionary theory the wolf into breeds as diverse as the does some math. He calculates the prob- dictates. You start by rolling the first die, greyhound, the dachshund, and the chi- ability that such interactions between and keep rolling it until a six comes up. huahua, and the wild mustard into cab- amino acids could evolve, assuming that When it does, you keep that die (a suc- bage, broccoli, cauliflower, and brussels a precise set of amino acids is required. cessful first step in the adaptation) and sprouts. Virtually every fruit, vegetable, Not surprisingly, it turns out that get- move on to the next one. You toss the sec- and meat that we eat has been drasti- ting by mutation a set of three to four ond die until it comes up six (the second cally remodeled by the artificial selec-

42 June 18, 2007 The New Republic tion of wild ancestors. All these changes scientific. Which features of life were de- cles. So you can choose between the two have been immeasurably faster than evo- signed, as opposed to evolved? How ex- possibilities: either mutations occurred in lution in the wild, which takes hundreds actly did the mutations responsible for one big miracle or in millions of little mir- of thousands to millions of years. And all design come about? Who was the De- acles. The first claim is religious and false. of these changes have involved selection signer? To what end did the Designer The second claim is religious and untest- of random mutations. After all, commer- work? If the goal was perfection, why are able. Neither claim is scientific. cial corn, greyhounds, tomatoes, and tur- some features of life (such as our appendix keys were redesigned by humans, not the or prostate gland) palpably imperfect? ho, precisely, was the De- Intelligent Designer, and since humans signer? Here Behe weasels a bit, cannot produce miracle mutations, we n response to the question of what as he should given the federal are limited to selecting whichever ones exactly was designed, Behe’s answer Wjudiciary’s dislike of religion in the sci- arise—that is, random ones. To think seems to be: pretty much everything, ence classroom. He mentions that the otherwise would require the extraor- Iincluding cells, biochemical systems, Christian God is only one of several pos- dinary assumption that the Designer and the features distinguishing major sibilities. But you can bet that it was not foresaw the intentions of breeders and groups of organisms, such as wings and Brahma, or the Bushmen’s Kaang, or a supplied them with the appropriate mi- warm-bloodedness. Behe’s criterion is space alien. As Jones remarked in Kitz- raculous mutations. The success of ani- basically twofold: a feature of life must miller v. Dover: “Consider, to illustrate, mal and plant breeding, far outstripping have been designed if it consists of a that Professor Behe remarkably and un- the pace of evolution in nature, is a se- “purposeful arrangement of parts” and mistakably claims that the plausibility of vere rebuke to Behe’s view that evolution is composed of at least three parts. the argument for ID depends upon the cannot work unless God helps it along by But when we see something that looks extent to which one believes in the exis- producing nonrandom mutations. designed, how do we know whether that tence of God.” It is disingenuous of IDers design is “purposeful”? Natural selec- to pretend that the Great Designer is un- VI. tion displaced divine design precisely known. Intelligent design has deep roots s the philosopher Philip Kitcher because it offered a naturalistic explana- in fundamentalist Christianity, and its shows in his superb new book, tion for things that appeared to be pur- advocates are not fooling anyone. Living With Darwin, the theory of poseful. And why three components? And what were the Designer’s goals? Aintelligent design is a mixture of “dead This appears to come from Behe’s claim This is where Behe really gives away the science” and non-science. That is, insofar that three amino acids are unlikely to game. He asserts that the goal was “intelli- as ID makes scientific claims (for exam- change simultaneously in a protein. Well, gent life.” Of course, what he really means ple, that natural selection cannot pro- that claim is true, but it has nothing to is humans, presumably because Chris- duce complexity), those claims not only do with protein evolution, much less with tians (Behe is a Catholic) feel that humans are wrong, but were proved wrong years the evolution of complex features. As we were made in the image of God: “What we ago. And ID is deeply unscientific in its know from the fossil record, the multi- sense, as elaborated through modern sci- assertion that certain aspects of evolu- ple features of organisms that make them ence’s instruments and our reasoning, is tion (mutation, in Behe’s case) required look designed—say, the feathers, legs, and that we live in a universe fine-tuned for in- intervention. Behe’s attacks wings of birds—did not appear instantly telligent life.” And elsewhere: “Parts were on evolutionary theory are once again and simultaneously, but evolved gradu- moving into place over geological time wrongheaded, but the intellectual situ- ally. There is not the slightest connection for the subsequent, purposeful, planned ation grows far worse when we see what between the likelihood of three binding emergence of intelligent life.” theory he offers in its place. sites appearing simultaneously in a pro- From God’s mouth to Behe’s ear! At The first problem is that Behe’s “sci- tein and the likelihood of three features this point we can simply stop asking entific” ideas are offered to the public of an organism evolving. Conflating these whether Behe’s theory is scientific, for in a trade book, and have never gone issues, and hoping that the reader will not he provides not the slightest evidence through the usual process of vetting in notice, must be a deliberate rhetorical that evolution had any goal, much less peer-reviewed scientific journals. This trick on Behe’s part, for surely even he is one of intelligent life. In fact, every form was also the case with Darwin’s Black not that ignorant of basic biology. of life on Earth, from humans to ferns to Box. In fact, Behe has never published How did the non-random mutations squirrels, can trace its ancestry back to a paper supporting intelligent design in come about? Well, they were obviously the same single species that lived about any , despite his asser- created by the Intelligent Designer. In three and a half billion years ago. In that tion in Darwin’s Black Box that his own Darwin’s Black Box, Behe made the outra- sense, all species are equally evolved and discovery of biochemical design “must geous claim that the Designer might have equally removed in time from life’s ori- be ranked as one of the greatest achieve- engineered the first cell to containall the gin. Science long ago dispensed with the ments in the history of science,” rivaling mutations for the evolution of every spe- notion of the scala natura: a progres- “those of Newton and Einstein, Lavoisier cies that would ever exist. This claim is sive ladder of life with humans at the top. and Schrödinger, Pasteur, and Darwin.” manifestly false: such a cell would have Rather, each existing species is at the tip Surely such an important theory de- unmanageably large amounts of DNA, of a branch on the tree of life. So what serves a place in the scientific literature! and we see no evidence of “future DNA scientific reason can there be for sin- But the reason for the lack of reserves” in primitive organisms such gling out just one species as the Design- is obvious: Behe’s ideas would never pass as . Behe still raises this possi- er’s goal? How do we know that the goal muster among scientists, despite the fact bility in his new book, but he also floats was not butterflies or sunflowers? Plainly, that anybody who really could disprove another idea: that mutations might not Behe is adopting religious dogma as part Darwinism would win great renown. have been built into the first organism of his theory. Yet he continues to assert So let us put some empirical questions but could have occurred later, foreseen that “I regard design as a completely sci- to Behe, since his theory is supposedly by God. In other words, they were mira- entific conclusion.”

The New Republic June 18, 2007 43 And what about the features of organ- that it is powerless to explain complexity. in Canada, went and looked at them, and isms that do not look well designed, such And it is certainly true that scientists will found the right fossils. Intelligent design, as the appendix, the vestigial wings of the never be able to give Darwinian expla- in contrast, makes no predictions. It is kiwi bird, or the vestigial pelvis of whales? nations for the evolution of everything. infinitely malleable in the face of coun- In Darwin’s Black Box, Behe punted and The origins of many features, such as the terevidence, cannot be refuted, and is said that the Designer’s goals were un- bony plates on the back of the Stegosau- therefore not science. knowable: “Features that strike us as odd rus, are lost in the irrecoverable past. But in a design might have been placed there neither can archaeology unearth every- n the end, The Edge of Evolution is by the designer for a reason—for artistic thing about ancient history. We do not not an advance or a refinement of the reasons, for variety, to show off, for some maintain on these grounds that archae- theory of intelligent design, but a re- as-yet-undetected practical purpose, or ology is not a science. Itreat from its original claims—an act of for some unguessable reason—or they Behe waffles when confronted with desperation designed to maintain credi- might not.” But if we do not know why the the testability problem of ID and turns it bility in a world of scientific progress. But Designer did things, how can we possibly back on evolutionists, saying that “com- it is all for nothing, because Behe’s new know that his goal was intelligent life? ing from Darwinists, both objections theory remains the same old mixture of [the lack of predictions and the untest- dead science and thinly disguised the- inally Behe gets to theodicy: why ability of ID] are instances of the pot ology. There is no evidence for his main is there pain and evil in the world if calling the kettle black.” He then waffles claim of non-random mutation, and sci- the Designer is omnipotent? How even more when implying that ID does entists have plenty of evidence against Fcome He/She/It allows innocent babies not even need to be testable: “Both ad- it. His arguments against the Darwin- to get sickle-cell anemia? Behe’s answer ditional demands—for hard-and-fast ian evolution of complex organisms are is that “maybe the Designer isn’t all that predictions or for direct evidence of a flawed and misleading. And there is not beneficent or omnipotent. Science can’t theory’s fundamental principle—are a shred of evidence supporting his claim answer questions like that.” But questions disingenuous. Philosophers have long that the goal of evolution is intelligent about the goals, the powers, and the limi- known that no simple criterion, includ- life. In contrast to the feast of evidence tations of the Designer are precisely what ing prediction, automatically qualifies or that nourishes evolutionary theory, Behe must be answered if ID is to become sci- disqualifies something as science, and gives us an empty plate. entific. After all, we do know something fundamental entities invoked by a the- The overweening strategy of IDers, about the power and the limitations of ory can remain mysterious for centuries, and their creationist forebears, is to natural selection, a process that can ex- or indefinitely.” say that everything that we do not un- plain pain and things that seem evil. But who is being disingenuous here? derstand is evidence of the existence of Is Behe’s theory testable? Well, not Evolution has been tested, and confirmed, God. I can imagine IDers of two centu- really, since it consists not of positive many times over. Every time we find ries ago claiming that God made the sun assertions, but of criticisms of evolu- an early human fossil dating back sev- shine, because until 1938 we had no idea tionary theory and solemn declarations eral million years, it confirms evolution. where all that energy came from. It was Every time a new tran- not until quantum mechanics arrived out sitional fossil is found, of left field that the physicist Hans Bethe such as the recently was able to surmise, correctly, that the Sound and Light discovered “missing sun is a giant fusion reactor, converting All these years and I still don’t understand links” between land hydrogen atoms into helium and energy. how it works, how the signal gets through animals and whales, Who knew? the bones of my hand, the bricks of this house, it confirms evolution. One of the great joys of science is that the bank building opposite, and across miles Each time a bacterial we never know what will happen next. strain becomes resis- Who could have guessed twenty years of suburb and field, pylons and roads, tant to an antibiotic, ago that dinosaurs probably became ex- hills and four rivers to precisely you, it confirms evolution. tinct after a giant meteorite collided with in another city, another house, another room, And evolutionary biol- Earth and produced a “nuclear winter”? hunched by the bath with your phone in your hand, ogy makes predictions. IDers would deprive us of this essen- Here is one that Dar- tial excitement, urging us to stop work- sobbing. You can’t bear to feel so split, win himself made: that ing when we come up against the hard you gasp. Downstairs you hear the earliest human an- problems and to ascribe our difficul- a chair scrape, a man’s voice. cestors will be found in ties to God. They would have us join the He laughs, in dialogue with another ghost. Africa. (That predic- herd of the benighted who proclaim so tion was confirmed, of confidently that they have descried the But I understand how light works. course.) Another was bounds of our knowledge. But this atti- Earlier your back gleamed like a guitar. made by Neil Shubin tude, this philosophy, was anticipated The last leaves on the sycamore at the University of and unmasked by none other than Dar- flickered like a school of mackerel. Chicago: that transi- win himself, who was prescient not only Later I will go out in a leopard-coat of light tional forms between about biology, but also about the nature without you: just me and the trees baring themselves fish and amphibians of science: “Ignorance more frequently for winter, and the marbled paving stones, would be found in begets confidence than does knowledge: and my empty hand shining. 370-million-year-old it is those who know little, and not those rocks. Sure enough, he who know much, who so positively as- Henry Shukman discovered that there sert that this or that problem will never were rocks of that age be solved by science.” d

44 June 18, 2007 The New Republic