The Illusion of Design
By Richard Dawkins
http://www.naturalhistorymag.com/master.html?http://www.naturalhistorymag.com/1105/1105_feature1.html

The world is divided into things that look as though somebody designed them (wings and wagon-wheels, hearts and televisions), and things that just happened through the unintended workings of physics (mountains and rivers, sand dunes, and solar systems). Mount Rushmore belonged firmly in the second category until the sculptor Gutzon Borglum carved it into the first. Charles Darwin moved in the other direction. He discovered a way in which the unaided laws of physics—the laws according to which things “just happen”—could, in the fullness of geologic time, come to mimic deliberate design. The illusion of design is so successful that to this day most Americans (including, significantly, many influential and rich Americans) stubbornly refuse to believe it is an illusion. To such people, if a heart (or an eye or a bacterial flagellum) looks designed, that’s proof enough that it is designed.

No wonder Thomas Henry Huxley, “Darwin’s bulldog,” was moved to chide himself on reading the Origin of Species: “How extremely stupid not to have thought of that.” And Huxley was the least stupid of men. The breathtaking power and reach of Darwin’s idea—extensively documented in the field, as Jonathan Weiner reports in “Evolution in Action”—is matched by its audacious simplicity. You can write it out in a phrase: nonrandom survival of randomly varying hereditary instructions for building embryos. Yet, given the opportunities afforded by deep time, this simple little algorithm generates prodigies of complexity, elegance, and diversity of apparent design. True design, the kind we see in a knapped flint, a jet plane, or a personal computer, turns out to be a manifestation of an entity—the human brain—that itself was never designed, but is an evolved product of Darwin’s mill.

Paradoxically, the extreme simplicity of what the philosopher Daniel C. Dennett called Darwin’s dangerous idea may be its greatest barrier to acceptance. People have a hard time believing that so simple a mechanism could deliver such powerful results.

The arguments of creationists, including those creationists who cloak their pretensions under the politically devious phrase “intelligent-design theory,” repeatedly return to the same big fallacy. Such-and-such looks designed. Therefore it was designed. To pursue my paradox, there is a sense in which the skepticism that often greets Darwin’s idea is a measure of its greatness. Paraphrasing the twentieth-century population geneticist Ronald A. Fisher, natural selection is a mechanism for generating improbability on an enormous scale. Improbable is pretty much a synonym for unbelievable. Any theory that explains the highly improbable is asking to be disbelieved by those who don’t understand it.

Yet the highly improbable does exist in the real world, and it must be explained. Adaptive improbability—complexity—is precisely the problem that any theory of life must solve and that natural selection, uniquely as far as science knows, does solve. In truth, it is intelligent design that is the biggest victim of the argument from improbability. Any entity capable of deliberately designing a living creature, to say nothing of a universe, would have to be hugely complex in its own right.

If, as the maverick astronomer Fred Hoyle mistakenly thought, the spontaneous origin of life is as improbable as a hurricane blowing through a junkyard and having the luck to assemble a Boeing 747, then a divine designer is the ultimate Boeing 747. The designer’s spontaneous origin ex nihilo would have to be even more improbable than the most complex of his alleged creations. Unless, of course, he relied on natural selection to do his work for him! And in that case, one might pardonably wonder (though this is not the place to pursue the question), does he need to exist at all?

The achievement of nonrandom natural selection is to tame chance. By smearing out the luck, breaking down the improbability into a large number of small steps—each one somewhat improbable but not ridiculously so—natural selection ratchets up the improbability. As the generations unfold, ratcheting takes the cumulative improbability up to levels that—in the absence of the ratcheting—would exceed all sensible credence.

Many people don’t understand such nonrandom cumulative ratcheting. They think natural selection is a theory of chance, so no wonder they don’t believe it! The battle that we biologists face, in our struggle to convince the public and their elected representatives that evolution is a fact, amounts to the battle to convey to them the power of Darwin’s ratchet—the blind watchmaker—to propel lineages up the gentle slopes of Mount Improbable.

The misapplied argument from improbability is not the only one deployed by creationists. They are quite fond of gaps, both literal gaps in the fossil record and gaps in their understanding of what Darwinism is all about. In both cases the (lack of) logic in the argument is the same. They allege a gap or deficiency in the Darwinian account. Then, without even inquiring whether intelligent design suffers from the same deficiency, they award victory to the rival “theory” by default. Such reasoning is no way to do science. But science is precisely not what creation “scientists,” despite the ambitions of their intelligent-design bullyboys, are doing.

In the case of fossils, as Donald R. Prothero documents in “The Fossils Say Yes” [see the print issue], today’s biologists are more fortunate than Darwin was in having access to beautiful series of transitional stages: almost cinematic records of evolutionary changes in action. Not all transitions are so attested, of course—hence the vaunted gaps. Some small animals just don’t fossilize; their phyla are known only from modern specimens: their history is one big gap. The equivalent gaps for any creationist or intelligent-design theory would be the absence of a cinematic record of God’s every move on the morning that he created, for example, the bacterial flagellar motor. Not only is there no such divine videotape: there is a complete absence of evidence of any kind for intelligent design.

Absence of evidence for is not positive evidence against, of course. Positive evidence against evolution could easily be found—if it exists. Fisher’s contemporary and rival J.B.S. Haldane was asked by a Popperian zealot what would falsify evolution. Haldane quipped, “Fossil rabbits in the Precambrian.” No such fossil has ever been found, of course, despite numerous searches for anachronistic species.

There are other barriers to accepting the truth of Darwinism. Many people cannot bear to think that they are cousins not just of chimpanzees and monkeys, but of tapeworms, spiders, and bacteria. The unpalatability of a proposition, however, has no bearing on its truth. I personally find the idea of cousinship to all living species positively agreeable, but neither my warmth toward it, nor the cringing of a creationist, has the slightest bearing on its truth.

The same could be said of political or moral objections to Darwinism. “Tell children they are nothing more than animals and they will behave like animals.” I do not for a moment accept that the conclusion follows from the premise. But even if it did, once again, a disagreeable consequence cannot undermine the truth of a premise. Some have said that Hitler founded his political philosophy on Darwinism. This is nonsense: doctrines of racial superiority in no way follow from natural selection, properly understood. Nevertheless, a good case can be made that a society run on Darwinian lines would be a very disagreeable society in which to live. But, yet again, the unpleasantness of a proposition has no bearing on its truth.

Huxley, George C. Williams, and other evolutionists have opposed Darwinism as a political and moral doctrine just as passionately as they have advocated its scientific truth. I count myself in that company. Science needs to understand natural selection as a force in nature, the better to oppose it as a normative force in politics. Darwin himself expressed dismay at the callousness of natural selection: “What a book a Devil’s Chaplain might write on the clumsy, wasteful, blundering low & horridly cruel works of nature!”

In spite of the success and admiration that he earned, and despite his large and loving family, Darwin’s life was not an especially happy one. Troubled about genetic deterioration in general and the possible effects of inbreeding closer to home, as James Moore documents in “Good Breeding” [see print issue], and tormented by illness and bereavement, as Richard Milner’s interview with the psychiatrist Ralph Colp Jr. shows in “Darwin’s Shrink,” Darwin’s achievements seem all the more. He even found the time to excel as an experimenter, particularly with plants. David Kohn’s and Sheila Ann Dean’s essays (“The Miraculous Season” and “Bee Lines and Worm Burrows” [see print issue]) lead me to think that, even without his major theoretical achievements, Darwin would have won lasting recognition as an experimenter, albeit an experimenter with the style of a gentlemanly amateur, which might not find favor with modern journal referees.

As for his major theoretical achievements, of course, the details of our understanding have moved on since Darwin’s time. That was particularly the case during the synthesis of Darwinism with Mendelian digital genetics. And beyond the synthesis, as Douglas J. Futuyma explains in “On Darwin’s Shoulders,” [see print issue] and Sean B. Carroll details further for the exciting new field of “evo-devo” in “The Origins of Form,” Darwinism proves to be a flourishing population of theories, itself undergoing rapid evolutionary change.

In any developing science there are disagreements. But scientists—and here is what separates real scientists from the pseudoscientists of the school of intelligent design—always know what evidence it would take to change their minds. One thing all real scientists agree upon is the fact of evolution itself. It is a fact that we are cousins of gorillas, kangaroos, starfish, and bacteria. Evolution is as much a fact as the heat of the sun. It is not a theory, and for pity’s sake, let’s stop confusing the philosophically naive by calling it so. Evolution is a fact.


Show Me the Science
By Daniel C. Dennett
http://ase.tufts.edu/cogstud/papers/ShowMetheScience.pdf

PRESIDENT BUSH, announcing this month that he was in favor of teaching about "intelligent design" in the schools, said, "I think that part of education is to expose people to different schools of thought." A couple of weeks later, Senator Bill Frist of Tennessee, the Republican leader, made the same point. Teaching both intelligent design and evolution "doesn't force any particular theory on anyone," Mr. Frist said. "I think in a pluralistic society that is the fairest way to go about education and training people for the future."

Is "intelligent design" a legitimate school of scientific thought? Is there something to it, or have these people been taken in by one of the most ingenious hoaxes in the history of science? Wouldn't such a hoax be impossible? No. Here's how it has been done.

First, imagine how easy it would be for a determined band of naysayers to shake the world's confidence in quantum physics - how weird it is! - or Einsteinian relativity. In spite of a century of instruction and popularization by physicists, few people ever really get their heads around the concepts involved. Most people eventually cobble together a justification for accepting the assurances of the experts: "Well, they pretty much agree with one another, and they claim that it is their understanding of these strange topics that allows them to harness atomic energy, and to make transistors and lasers, which certainly do work..."

Fortunately for physicists, there is no powerful motivation for such a band of mischief-makers to form. They don't have to spend much time persuading people that quantum physics and Einsteinian relativity really have been established beyond all reasonable doubt.

With evolution, however, it is different. The fundamental scientific idea of evolution by natural selection is not just mind-boggling; natural selection, by executing God's traditional task of designing and creating all creatures great and small, also seems to deny one of the best reasons we have for believing in God. So there is plenty of motivation for resisting the assurances of the biologists. Nobody is immune to wishful thinking. It takes scientific discipline to protect ourselves from our own credulity, but we've also found ingenious ways to fool ourselves and others. Some of the methods used to exploit these urges are easy to analyze; others take a little more unpacking.


A creationist pamphlet sent to me some years ago had an amusing page in it, purporting to be part of a simple questionnaire:

Test Two

Do you know of any building that didn't have a builder? [YES] [NO]

Do you know of any painting that didn't have a painter? [YES] [NO]

Do you know of any car that didn't have a maker? [YES] [NO]

If you answered YES for any of the above, give details:

Take that, you Darwinians! The presumed embarrassment of the test-taker when faced with this task perfectly expresses the incredulity many people feel when they confront Darwin's great idea. It seems obvious, doesn't it, that there couldn't be any designs without designers, any such creations without a creator.

Well, yes - until you look at what contemporary biology has demonstrated beyond all reasonable doubt: that natural selection - the process in which reproducing entities must compete for finite resources and thereby engage in a tournament of blind trial and error from which improvements automatically emerge - has the power to generate breathtakingly ingenious designs.

Take the development of the eye, which has been one of the favorite challenges of creationists. How on earth, they ask, could that engineering marvel be produced by a series of small, unplanned steps? Only an intelligent designer could have created such a brilliant arrangement of a shape-shifting lens, an aperture-adjusting iris, a light-sensitive image surface of exquisite sensitivity, all housed in a sphere that can shift its aim in a hundredth of a second and send megabytes of information to the visual cortex every second for years on end.

But as we learn more and more about the history of the genes involved, and how they work - all the way back to their predecessor genes in the sightless bacteria from which multicelled animals evolved more than a half-billion years ago - we can begin to tell the story of how photosensitive spots gradually turned into light-sensitive craters that could detect the rough direction from which light came, and then gradually acquired their lenses, improving their information-gathering capacities all the while.

We can't yet say what all the details of this process were, but real eyes representative of all the intermediate stages can be found, dotted around the animal kingdom, and we have detailed computer models to demonstrate that the creative process works just as the theory says.

All it takes is a rare accident that gives one lucky animal a mutation that improves its vision over that of its siblings; if this helps it have more offspring than its rivals, this gives evolution an opportunity to raise the bar and ratchet up the design of the eye by one mindless step. And since these lucky improvements accumulate - this was Darwin's insight - eyes can automatically get better and better and better, without any intelligent designer.

Brilliant as the design of the eye is, it betrays its origin with a tell-tale flaw: the retina is inside out. The nerve fibers that carry the signals from the eye's rods and cones (which sense light and color) lie on top of them, and have to plunge through a large hole in the retina to get to the brain, creating the blind spot. No intelligent designer would put such a clumsy arrangement in a camcorder, and this is just one of hundreds of accidents frozen in evolutionary history that confirm the mindlessness of the historical process.

If you still find Test Two compelling, a sort of cognitive illusion that you can feel even as you discount it, you are like just about everybody else in the world; the idea that natural selection has the power to generate such sophisticated designs is deeply counterintuitive. Francis Crick, one of the discoverers of DNA, once jokingly credited his colleague Leslie Orgel with "Orgel's Second Rule": Evolution is cleverer than you are. Evolutionary biologists are often startled by the power of natural selection to "discover" an "ingenious" solution to a design problem posed in the lab.

This observation lets us address a slightly more sophisticated version of the cognitive illusion presented by Test Two. When evolutionists like Crick marvel at the cleverness of the process of natural selection they are not acknowledging intelligent design. The designs found in nature are nothing short of brilliant, but the process of design that generates them is utterly lacking in intelligence of its own.

Intelligent design advocates, however, exploit the ambiguity between process and product that is built into the word "design." For them, the presence of a finished product (a fully evolved eye, for instance) is evidence of an intelligent design process. But this tempting conclusion is just what evolutionary biology has shown to be mistaken.

Yes, eyes are for seeing, but these and all the other purposes in the natural world can be generated by processes that are themselves without purposes and without intelligence. This is hard to understand, but so is the idea that colored objects in the world are composed of atoms that are not themselves colored, and that heat is not made of tiny hot things.

The focus on intelligent design has, paradoxically, obscured something else: genuine scientific controversies about evolution that abound. In just about every field there are challenges to one established theory or another. The legitimate way to stir up such a storm is to come up with an alternative theory that makes a prediction that is crisply denied by the reigning theory - but that turns out to be true, or that explains something that has been baffling defenders of the status quo, or that unifies two distant theories at the cost of some element of the currently accepted view.

To date, the proponents of intelligent design have not produced anything like that. No experiments with results that challenge any mainstream biological understanding. No observations from the fossil record or genomics or biogeography or comparative anatomy that undermine standard evolutionary thinking.

Instead, the proponents of intelligent design use a ploy that works something like this. First you misuse or misdescribe some scientist's work. Then you get an angry rebuttal. Then, instead of dealing forthrightly with the charges leveled, you cite the rebuttal as evidence that there is a "controversy" to teach.

Note that the trick is content-free. You can use it on any topic. "Smith's work in geology supports my argument that the earth is flat," you say, misrepresenting Smith's work. When Smith responds with a denunciation of your misuse of her work, you respond, saying something like: "See what a controversy we have here? Professor Smith and I are locked in a titanic scientific debate. We should teach the controversy in the classrooms." And here is the delicious part: you can often exploit the very technicality of the issues to your own advantage, counting on most of us to miss the point in all the difficult details.

William Dembski, one of the most vocal supporters of intelligent design, notes that he provoked Thomas Schneider, a biologist, into a response that Dr. Dembski characterizes as "some hair-splitting that could only look ridiculous to outsider observers." What looks to scientists - and is - a knockout objection by Dr. Schneider is portrayed to most everyone else as ridiculous hair-splitting.

In short, no science. Indeed, no intelligent design hypothesis has even been ventured as a rival explanation of any biological phenomenon. This might seem surprising to people who think that intelligent design competes directly with the hypothesis of non-intelligent design by natural selection. But saying, as intelligent design proponents do, "You haven't explained everything yet," is not a competing hypothesis. Evolutionary biology certainly hasn't explained everything that perplexes biologists. But intelligent design hasn't yet tried to explain anything.

To formulate a competing hypothesis, you have to get down in the trenches and offer details that have testable implications. So far, intelligent design proponents have conveniently sidestepped that requirement, claiming that they have no specifics in mind about who or what the intelligent designer might be.

To see this shortcoming in relief, consider an imaginary hypothesis of intelligent design that could explain the emergence of human beings on this planet:

About six million years ago, intelligent genetic engineers from another galaxy visited Earth and decided that it would be a more interesting planet if there was a language-using, religion-forming species on it, so they sequestered some primates and genetically re-engineered them to give them the language instinct, and enlarged frontal lobes for planning and reflection. It worked.

If some version of this hypothesis were true, it could explain how and why human beings differ from their nearest relatives, and it would disconfirm the competing evolutionary hypotheses that are being pursued.

We'd still have the problem of how these intelligent genetic engineers came to exist on their home planet, but we can safely ignore that complication for the time being, since there is not the slightest shred of evidence in favor of this hypothesis.

But here is something the intelligent design community is reluctant to discuss: no other intelligent design hypothesis has anything more going for it. In fact, my farfetched hypothesis has the advantage of being testable in principle: we could compare the human and chimpanzee genomes, looking for unmistakable signs of tampering by these genetic engineers from another galaxy. Finding some sort of user's manual neatly embedded in the apparently functionless "junk DNA" that makes up most of the human genome would be a Nobel Prize-winning coup for the intelligent design gang, but if they are looking at all, they haven't come up with anything to report.

It's worth pointing out that there are plenty of substantive scientific controversies in biology that are not yet in the textbooks or the classrooms. The scientific participants in these arguments vie for acceptance among the relevant expert communities in peer-reviewed journals, and the writers and editors of textbooks grapple with judgments about which findings have risen to the level of acceptance - not yet truth - to make them worth serious consideration by undergraduates and high school students.

So get in line, intelligent designers. Get in line behind the hypothesis that life started on Mars and was blown here by a cosmic impact. Get in line behind the aquatic ape hypothesis, the gestural origin of language hypothesis and the theory that singing came before language, to mention just a few of the enticing hypotheses that are actively defended but still insufficiently supported by hard facts.

The Discovery Institute, the conservative organization that has helped to put intelligent design on the map, complains that its members face hostility from the established scientific journals. But establishment hostility is not the real hurdle to intelligent design. If intelligent design were a scientific idea whose time had come, young scientists would be dashing around their labs, vying to win the Nobel Prizes that surely are in store for anybody who can overturn any significant proposition of contemporary evolutionary biology.

Remember cold fusion? The establishment was incredibly hostile to that hypothesis, but scientists around the world rushed to their labs in the effort to explore the idea, in hopes of sharing in the glory if it turned out to be true.

Instead of spending more than $1 million a year on publishing books and articles for non-scientists and on other public relations efforts, the Discovery Institute should finance its own peer-reviewed electronic journal. This way, the organization could live up to its self-professed image: the doughty defenders of brave iconoclasts bucking the establishment.

For now, though, the theory they are promoting is exactly what George Gilder, a long-time affiliate of the Discovery Institute, has said it is: "Intelligent design itself does not have any content."

Since there is no content, there is no "controversy" to teach about in biology class. But here is a good topic for a high school course on current events and politics: Is intelligent design a hoax? And if so, how was it perpetrated?