Expelled: No Intelligence Allowed

Expelled: No Intelligence Allowed — Ben Stein Launches a Science-Free Attack on Darwin is an online article by Skeptic-in-Chief Michael Shermer, an edited version of which appears as "Expelled Exposed" in the June 2008 Scientific American. The article's topic is the documentary film recently produced by actor/game-show host/financial columnist Ben Stein. The movie's title, Expelled: No Intelligence Allowed, refers to how, in Stein's view, the "theory" of intelligent design has been exorcised falsely from our science classrooms.

Intelligent design is the name given by its proponents to the idea that important body structures — wings, eyes, brains, the gene-bearing double helix of DNA itself, and even the rotary flagellum that propels many bacteria — arose, during the course of Earth biohistory, against colossal odds that were insurmountable by nature acting alone. Because the odds against such complexity arising without any help from The Man Above were so huge, the only legitimate conclusion is that there must have been an Intelligent Designer outside this world whose activity helped evolution over several otherwise impossible humps.


To Shermer, intelligent design, not Darwinian evolution, is the idea that is false. Intelligent design shouldn't be taught in American classrooms as accepted scientific theory, because it isn't. It's an attempt to use scientific language to justify religious belief.

The standard theory of evolution, Shermer and other Darwinists hold, accounts fully for wings, eyes, brains, DNA ... and bacterial flagella. There are no insurmountable humps in the history of evolution guided by natural selection alone. Over the course of more than four billion years, there was a process of slow, steady change to the various genomes carried by the DNA molecule, once nature had invented that molecule. (The origin of DNA itself — the provenance of the very first genome-bearing life form — is admittedly still uncertain.)

All life forms but the first happened as a result of that slow process which Darwin called descent with modification. Down through Earth's long life history, genetic changes called mutations were culled by natural selection, an impersonal force that weeds out changes that harm the chances to survive of the organisms that possess them.

Genetic mutations that help their possessors survive are "adaptive," in evolutionary terms. Other mutations are neutral. Yet others are so harmful they cannot persist in the genome. Some can be harmful under specific circumstances, but still persist in a genome.

Yet others make for helpful new traits (or are neutral or even mildly harmful) and are later "exapted" — rededicated — to produce different adaptive effects than they originally had (if they had any at all). The dynamics of genetic change, whether or not any one change is immediately adaptive, are sufficiently rich for eyes, wings, etc. to arise by a long, slow, step-by-step process, none of whose individual steps is all that unlikely to occur.

That's the standard outlook on Darwinian evolutionary theory to which Shermer subscribes.

Shermer, because he is a professional skeptic, was interviewed by Stein for his movie, and Shermer in his article recounts how Stein kept badgering him to justify the supposed firing of teachers for advocating intelligent design. However, according to Shermer the alleged firings over intelligent design all had other explanations — see the Expelled Exposed website. Shermer thinks Stein is thus using non-facts about recent history as a basis for non-scientific propaganda about evolutionary facts.


To Stein, though, intelligent design is a theory that makes sense. Why? Apparently, in part because (in Stein's estimation, at least) Darwinian beliefs about God's non-involvement in the creation of Earth's living species are very, very harmful to human society. Writes Shermer:

Even more disturbing than [the film's] distortions [of science] is the film's other thesis that Darwinism inexorably leads to atheism, communism, fascism, and could be blamed for the Holocaust. Despite the fact that hundreds of millions of religious believers fully accept the theory of evolution, Stein claims that we are in an ideological war between a scientific natural worldview that leads to Stalin's gulag archipelago and Nazi gas chambers, and a religious supernatural worldview that leads to freedom, justice and the American way.

Shermer goes on to say:

When will people learn that Darwinian naturalism has nothing whatsoever to do with religious supernaturalism? By the very definitions of the words it is not possible for supernatural processes to be understood by a method designed strictly for analyzing natural causes. Unless God reaches into our world through natural and detectable means, he remains wholly outside the realm of science.

That first sentence starts out differently — "When will Americans learn that evolutionary theory has nothing to do with religion ... " — in the magazine condensation of the online article. I have a bit of a problem with that latter formulation. I think there are millions of American citizens who feel Darwinian naturalism clashes with their religious belief absolutely — so much so that without intelligent design, evolution as an idea is anathema to them.

To these people, if God remains outside the realm of science, so much the worse for science.

If science is put above God, it is only logical that widespread atheism would be the result, say these people. But if God is put above science, society benefits.


To me, the biggest question is, can there be an approach to truth that embraces both pure science and a belief in God?

I don't think I can really answer that. I'm an agnostic when it comes to the question of how God and science ought to mix.

On the other hand, I would like to investigate the question of why for some people God and evolution science can't mix — at least, not without an admixture of intelligent design, a proposition that (I agree with Shermer) does not pass the test of true science.

I myself don't believe intelligent design is good science because the arguments in its favor don't stack up.

One major pro-I.D. argument posits that even a bacterial flagellum has so many chemical building blocks, each originated by one or more genetic mutations, that it's like a classical arch. An arch cannot stand on its own until its keystone is dropped into place, but the keystone cannot be put in until the rest of the arch is built, using some kind of scaffolding. None of the stones makes sense until all of the stones make sense. Ergo, just as there has to be a designer-builder behind the arch, there has to be one behind a bacterial flagellum.

But the mutation-driven changes in cell chemistry that gave the bacterium its flagellum are not necessarily like stones in an arch. They don't have to stand in any particular relationship to one another until the final change — the "keystone mutation," as it were — happens. After that, the other "stones," protein templates that have presumably arisen in the bacterial genome for independent reasons, can have their erstwhile utility (if any) rededicated to become pieces of the flagellar puzzle.

In hindsight, it looks to us as if something in or above nature must have "wanted" a highly useful motor-propeller to arise in single-celled living creatures ... and as if that is exactly what happened. A comprehensible evolutionary "target" has been hit. Ipso facto, there must have been a skilled, intentional archer taking careful aim at this comprehensible target.

For to think otherwise would seem to require us to assume that "random" genetic changes, occurring one at a time over umpty-ump millions of years, could actually manage to hit such a complex target as the genetic blueprint for a motor-propeller. The odds against that, no matter how much of the entire age of the universe you allocate for it to transpire, are (supposedly) vanishingly small. Ipso facto, intelligent design must be true.


A Darwinist, however, would respond — as would I — that what has actually happened is that a terribly nearsighted archer (nature, not God) has accidentally shot an arrow in the general direction of a large wall, has managed to hit the wall somewhere, and then we in his audience have proceeded to paint a target around the spot where the arrow struck.

It is quite true that when various and sundry mutational changes, taking place over a very, very long stretch of geological time, one day just happen to cohere and produce something useful like a flagellum, natural selection assiduously ratifies the result by culling out organisms that lack the new device. These organisms are less fit, they die out more readily than their fitter cousins, and their inferior genes don't tend to make it into succeeding generations. The full accretion of mutations that go towards producing the innovative flagellum do get passed on — and a target in effect gets painted by nature around the spot on the wall representing a motor-propeller.

That's at least one explanation of the bacterial flagellum that I believe is consistent with Darwinist evolution theory as it is understood today. There may be other, better ones. But my point is that you don't need to invoke an Intelligent Designer to explain how a structure as complex as a flagellum arose in nature.

One of the ground rules of science is that in explaining a thing, no more assumptions should be made than are absolutely necessary. This principle of scientific parsimony is also known by the colorful name Occam's Razor, attributed to the 14th-century English logician and Franciscan friar William of Ockham.

If the assumptions of Darwinist evolution theory fully cover how flagella might have arisen in nature — and they do — Occam's Razor forbids the additional assumption that a God must have taken a hand in the creative process.


The question of how yet-more-complex structures such as eyes, wings, and brains arose has a similar Darwinian answer. Take the eye. There were intermediate stages between having no eye at all and having the complex organ we have today. Perhaps the first stage was for certain skin cells to, as the result of a genetic mutation, become sensitive to light.

Meanwhile, other mutations might cause the hard bone beneath the light-sensitive cells to form a shallow cup, so the organism could begin to tell from which direction light is coming from ... a useful clue as to which way is up. Organisms happening to possess both mutational changes would be fitter than their clueless cousins and multiply more fruitfully. The stage would be set for more mutations to turn the cup behind the proto-retina fully into an enclosing orb with a pinhole in it, thereby to allow an image of the outside world to come into focus.

Further genetic changes could then arrange to morph yet more skin cells into a crude lens for the eye-in-the-making, so that objects at various distances could be brought into clear focus. Etc., etc., etc. Eventually, you have an organism that in advanced age needs bifocals.

These Darwinian explanations for how things like flagella and eyes might arise without divine assistance are admittedly quite speculative. Most of the intermediate evolutionary stages no longer exist, and their original possessors did not, alas, fossilize. It is hard or impossible to find a bacterium with a proto-flagellum these days. Hard to find an extant primitive creature with a shallow cup where an eye socket ought one day to form.


But advocates of intelligent design have at least as difficult a row to hoe. After all, they are trying to prove a negative. They are trying to prove that Darwinian incrementalism did not, and could not, account for complex biological structures.

One version of the "proof" asserts that things like eyes, wings, and flagella are "irreducibly complex." There is simply no Darwinian pathway whatsoever by virtue of which living creatures could go from being wholly without eyes to being possessors of the complex organs we observe (and have) today.

All hypothetical mutational pathways go through, as it were, impassable swamps of evolutionary territory, according to this logic. Mutations are required that make no adaptive sense — until they are complemented by a host of other, equally senseless mutations, and finally the "keystone," whether flagellar or visual, is set in place. Individually, these mutations actually drain their possessor organisms of their very Darwinian fitness. They cause the organism to waste time and chemical energy making proteins that do nothing of benefit to the organism, or that actually poison the organism's chances of survival. Only when the full complement of mutant protein templates is in place in the organism's genome does the point of the exercise become clear: an innovative motor-propeller, or the novel light-gathering capability of a sunken patch of skin.

Hence, the argument for intelligent design goes, you can't get from being eyeless to having eyes by following a Darwinian road map. There has to be something else going on.

This is an argument that tries to prove a negative, and then turn it into a (supernatural) positive. The negative: Darwin was wrong about the power of random heritable variation, abetted by natural selection, to account for all the complexity of living creatures today. The positive: God, as Intelligent Designer, must have intervened at uncountable junctures along the way.


A second version of the argument, subtly different from the first but coming to the same conclusion, is that maybe, just maybe — in the abstract, conceptual realm, mind you — there might be a purely Darwinian pathway from eyelessness to eyes, but the chances of the "blind watchmaker" which evolution has been dubbed finding it in the few billion years our world has existed are slim and none.

It's like programming a computer to break the most elaborate ciphers known to those in the intelligence community. In theory, any cipher can be broken by a straightforward computer program, simply by trying every possible master key, one key after another after another. In practice, there aren't enough computer CPU cycles in the current age of the universe to scratch the surface of the problem.

It's like that with evolution, this second argument for intelligent design goes. There hasn't been enough time for blind luck to locate the evolutionary pathways that produce flagella, eyes, wings, brains, etc., without guidance from above.

Those who make this argument do a bit of back-of-the-envelope math and find that the numerical probability of nature's just accidentally hitting an evolutionary target on the list summarized above — eyes, wings, brains, flagella, etc. — is much smaller than is acceptable, if we are to believe that evolution's "watchmaker" is purely blind.

Hence, the negative proposition becomes a positive one: if there is an eye, then there must be a Designer of that eye.


My reaction to that argument is that it does not take into account the sciences of complexity.

Complexity science is only about forty years old, and as the new kid on the block it has its defenders and naysayers. It is related to the theory of chaos, though it claims to stand on its own as a legitimate science. Its basic discovery is that nonequilibrium dynamical systems in nature tend to gravitate to a mathematical locus called the "edge of chaos."

A dynamical system is one that by its very nature changes. Many dynamical systems change in a highly orderly and predictable way, while others are chaotic. The ones that are chaotic are exquisitely sensitive to initial conditions, to an extent that a butterfly beating its wings in Rio can cause a tornado in Texas. The outcome is deterministic — bound to happen — yet we can never predict that outcome.

A open, nonequilibrium dynamical system takes in and expels matter and energy, thereby immunizing itself at least temporarily to entropy. It can exist in highly ordered states, or it can be in chaos, depending in part on the rate of energy flow through it. But the sciences of complexity have found yet another region that its dynamics can inhabit: the edge of chaos.

At the edge of chaos it is subject to surprising, unpredictable changes which nonetheless gracefully persist for long periods of time. Truly chaotic systems create surprise, but lack graceful persistence.

Certain open nonequilibrium systems — those that we call alive — naturally seek and find the edge of chaos. They establish themselves at the point of enduring, graceful dynamical poise. If they are perturbed, they gravitate back to the poised state, and in so doing they give birth to yet more evolutionary surprises.

Living systems that evolve in a Darwinian sense have a hidden tendency to find the edge of chaos, and to return to it if disturbed — so say the advocates of complexity science. In so doing, they make for the nearly inevitable creation of high levels of biological complexity over evolutionary timescales.

The sciences of complexity give us one way to refute the argument of intelligent design's proponents that flagella and eyes, wings and brains are just too improbable to have arisen without divine guidance.