Saturday, June 04, 2005

Paging David Berlinski...

This past April evolution critic David Berlinski published this editorial in The Daily Californian. It began as follows:


Wearing pink tasseled slippers and conical hats covered in polka dots, Darwinian biologists are persuaded that a plot is afoot to make them look silly. At Internet web sites such as The Panda's Thumb or Talk Reason, where various eminences repair to assure one another that all is well, it is considered clever beyond measure to attack critics of Darwin's theory such as William Dembski by misspelling his name as William Dumbski.


As I pointed out in this previous blog entry, Berlinski simply invented out of whole cloth the idea that anyone affiliated with Talk Reason or The Panda's Thumb considers it clever to misspell William Dembski's name.

In a subsequent exchange of letters with the editors of Talk Reason, Berlinski wrote the following:


What is at issue is whether you regard infantile verbal abuse ranging from the distasteful /(William Dumbski, How creationists suck/) to the contemptuous (/The Art of ID Stuntmen/, /Icons of Obfuscation/) as clever. I have no way directly of knowing, of course. For all I know you may collectively wince when you read such stuff. If so, you have not winced conspicuously, the more so, I am minded to add, since you seem either to have written or to endorsed some of the stuff in question.


As I argued in my previous blog entry, there was no “infantile verbal abuse” going on in the examples Berlinski cites.

But since Berlinski seems terribly concerned about the level of discourse in this area, I'm sure he must be terribly disturbed by William Dembski's recent use of the term “Darwhiner” to describe his opponents. Meanwhile, ID proponent Denyse O'Leary prefers the term “Darwinbot”. In the comments to Dembski's post, O'Leary weighs in with some thoughts about the proper usage of such terms. Meanwhile, in the comments to this post over at John Lynch's excellent blog Stranger Fruit we find John Davison weighing in with “Darwimpian”.

Do you think Mr. Berlinski will open his next editorial with a criticism of the low level of discourse coming from his side of this issue?

Friday, June 03, 2005

Sewell, Part II

In Tuesday's post I began my analysis of Granville Sewell's recent attempt to revive the thermodynamics argument against evolution. I continue that analysis now.

Let us ponder for a moment the second law of thermodynamics.

In its simplest formulation the second law asserts that the entropy of a closed system can never decrease. A closed system is one that receives no energy from outside the system itself. Save for the universe as a whole there are no truly closed systems in nature. Even a well-insulated system in a laboratory setting will always be receiving some minimal input of energy from outside. Nonetheless, we can find systems that are sufficiently close to being closed systems to amount to the same thing.

But what is entropy? It is often described as randomness or disorder. This captures an important aspect of what it is about a system that entropy represents. It is not sufficiently precise, however, to be useful in actual applications. In reality entropy, like many terms in physics, has only a mathematical definition.

The concept of entropy was born out of the realization that there are certain natural processes that only proceed in one direction. Coffee and milk combine to form a murky, light brown liquid, but you will never see mixed coffee separate itself into black coffee and white milk. Air placed in one side of a box will quickly spread to fill the entire thing, but you will never see the air rush to one side of the box, leaving a vacuum on the other.

Since the first law of thermodynamics, conservation of energy, did not prohibit things like mixed coffee separating itself, it was concluded that there was some new principle of thermodynamics waiting to be discovered. And just as the first law dealt with the internal energy of a particular system, it was concluded that there ought to be some other property of physical systems that captured our notions about the inherent directionality of certain natural processes.

This ultimately led to the idea of the entropy of a system. Actually, though, at this stage of the game the entropy of a system was not actually defined (later, when statistical mechanics was brought to bear on the problem, that was changed). What was actually defined was the change in entropy of a system in going from state one to state two. This definition was purely mathematical (in other words, a formula expressed in terms of other known quantities was provided for it), but it had the virtue of being composed of quantities that could actually be measured in many important contexts.

It was a consequence of this definition that if all of the energy added to a system were converted to useful work, then the change in entropy that resulted would be zero. A process in which this maximum possible amount of work was attained was said to be reversible. The idea is that a process is reversible if some minimal amount of effort is sufficient to make the process run the other way. As a simple illustration, imagine that you have a see saw that is currently in balance. Now imagine placing a small weight (in theory, even a grain of sand should be sufficient) on one side of the see saw. The result will be that one side of the see saw will be lowered, while the other side will be raised. If we assume there is no friction between the movable parts of the see saw, then the loss of potential energy on the lowered side is matched exactly by the gain in potential energy of the raised side. If we now removed the weight from the lowered side, the see saw would return to its original state. This process is therefore reversible.

In reality, of course, there are no perfectly reversible processes. Some of the kinetic energy imparted to the see saw by the addition of the weight on one side would translate not into increased potential energy on the other side, but rather into heat generated by the friction between the see saw's movable parts.

Consequently, it was realized that in real life processes the change in entropy would always be positive. In other words, entropy would always increase in a real life process. In certain idealized processes the entropy change could be zero. But it could never happen that the entropy of the system decreased.

At this point we encounter a complication. The formula by which the change in entropy was defined was only valid for reversible processes. It could be extended to irreversible processes by imagining some hypothetical series of reversible processes whose start and end states were the same as those you were interested in. This is possible because the entropy of the system depends only on the state that system is in. Therefore, the entropy change depends only on the start and end states, and not on the path that led you from state one to state two. For this reason, the entropy change is said to be “independent of path&rdquo.;

In real-life all processes are irreversible. But some are sufficiently close to being reversible to make little practical difference. Generally speaking, the processes that are “close enough” are those that are close to thermdynamic equilibrium at every stage of the processes. Roughly, this means that the large-scale properties of the system are making only very small changes at each stage of the process.

So what does this have to do with evolution? Well, let us take as our initial state the lifeless Earth of four billion years ago. As our final state we will use the Earth of today. Certainly the highly complex organisms of today are more highly ordered than their disassembled component parts four billion years ago. So we might say that entropy has decreased during that time.

But by itself this is far too imprecise to argue that evolution on Earth has run afoul of the second law. What is needed is a precise measurement of the decrease in entropy that has occurred on Earth in the last four billion years. We also need to consider that the second law applies only to closed systems, while the Earth is contantly being showered with energy from the Sun (among other sources).

As an approximation we might say that the Earth and Sun together are pretty close to a closed system. The would-be critic of evolution must now establish that the entropy of this system has decreased in the last four billion years.

Which brings us, finally, to two points that are fatal to any attempt to disprove evolution via the second law.

First, measurements of entropy change are practical only for systems that are very close to equilibrium at every step. But living organisms are the consummate examples of nonequilibrium systems. As a result, it is effectively impossible to say by how much the entropy of the Earth has decreased in the course of evolution. How do you compute the entropy of a biosphere? No one knows.

Second, even granting that entropy has decreased on the Earth, we would have to show that this decrease was not offset by increases elsewhere. But the entropy of the Sun is increasing by enormous quantities every day. Even a crude overestimate of the entropy decrease of the Earth over four billion years would show that it is no match for the corresponding increase in entropy in the Sun.

So the second law of thermodynamics does not contradict, or provide reason for challenging, modern evolutionary theory. Period. Anyone who says otherwise is wrong as a simple matter of fact.

But creationists have never let something as simple as the truth prevent them from using an argument. So they will argue that even in an open system we don't naturally expect order to increase. This is the tack taken by Sewell in his essay, who goes on to discuss some of the standard cliches for why known evolutionary mechanisms can not produce cpmplex systems. We will discuss that part of his essay in the next installment of this series.

What is important for now, however, is to note that the second law of thermodynamics is a pure red herring in this argument. In other words, the second law is of absolutely no help at all to Sewell in making his case. Everyone agrees that the growth in complexity that has happened over the last four billion years requires an explanation. It is everyday experience, and not any considerations arising from the seond law, that leads to this agreement. The argument, such as it is, is about whether known mechanisms are up to the task of explaining that complexity increase.

Even if it were someday shown that known natural mechanisms were not up to the task (ID folks claim that day has come, but they are wrong to make that claim), we still would not have a contradiction between evolution and the second law. Sewell raises the issue either because he hasn't the faintest idea what he's talking about, or because he's trying to snow people by invoking technical terminology to cover a bad argument.

Thursday, June 02, 2005

I'm an Uncle!

Earlier today I received word that my brother, Neil and sister-in-law, Elana just had their first baby, Noah. Congratulations! Both mother and nephew are doing fine.

Tuesday, May 31, 2005

Sewell, Part I

Update: June 2, 2005: In my original version of this post, I incorrectly suggested that Dr. Sewell had neglected to take quantum uncertainty into consideration in his description of a hypothetical computer simulation. I have now corrected that error, and have rewritten the relevant paragraph.




Something seems to happen to a person when he decides to reject evolutionary theory. He suddenly becomes incapable of saying anything correct or coherent about scientific research. His arrogance explodes out of all proportion to his accomplishments. He feels compelled to present the most ludicrous caricatures of modern science.

Take Granville Sewell, for example.

Sewell is a mathematician currently visiting Texas A&M University. He has recently posted this article (PDF format) at his website, in which he argues that the second law of thermodynamics is at odds with evolutionary theory. Since this is one of the oldest, and dumbest, canards against evolution, perhaps it's worth saying a few words about the argument he offers.

But first, some history. In 2000, Sewell published this article in The Mathematical Intelligencer. In it he raised two arguments against evolution: That natural selection can not craft complex biological systems and the aforementioned thermodynamics argument.

It was a pretty bad article, but the Intelligencer was, at least, kind enough to publish this essay of mine, among other replies, in a subsequent issue. Actually, only a small portion of this essay was intended as a reply to Sewell.

Incredibly, the Intelligencer then saw fit to give even more space to Sewell for a reply to the replies, but as far as I was concerned the issue was over. But now it seems Sewell wants to enter the fray once more.

His current essay is entitled “Can ANYTHING Happen in an Open System?” (Emphasis in original). That title, all by itself, is a dead giveaway that you are about to read a very silly argument indeed. Of course not just anything can happen in an open system. No one has ever claimed otherwise. That Sewell would frame the argument that way is a sure sign that he is more interested in knocking down strawmen and caricatures than he is in discussing science.

But we will come to that in a future post. You see, like most creationists, Sewell lards up his writing with so much outright nonsense that you must do a fair amount of debris clearing before you can address anything of substance. For example, here's Sewell explaining the problem evolution faces:


The discovery that life on Earth developed through evolutionary “steps”, coupled with the observation that mutations and natural selection - like other natural forces - can cause (minor) change, is widely accepted in the scientific world as proof that natural selection-alone among all natural forces-can create order
out of disorder, and even design human brains, with human consciousness. Only
the layman seems to see the problem with this logic. In a recent Mathematical
Intelligencer article [Sewell 2000], after outlining the specific reasons why it
is not reasonable to attribute the major steps in the development of life to natural
selection, I asserted that the idea that the four fundamental forces of physics
alone could rearrange the fundamental particles of Nature into spaceships, nuclear
power plants, and computers, connected to laser printers, CRTs, keyboards
and the Internet, appears to violate the second law of thermodynamics in a spectacular
way.


As I said, so much nonsense.

In the opening sentence Sewell seems to agree that life on Earth is the product of evolution. That part's not nonsense. The nonsense begins when he suggests that a few observations of microevolution are the basis for the conclusion that natural selection is one of the primary shapers of evolutionary change. Studies of microevolution are certainly important and suggestive, but they are only a small part of the case for natural selection's role in evolution.

There is also the fact that every complex system studied in detail has just the structure it ought to have if it formed gradually via known evolutionary mechanisms. Biologists have found copious evidence of tinkering and bootstrapping in complex systems. Furthermore, for a great many systems scientists have been able to discern likely intermediate stages.

There is the fact that “adaptaionist” thinking has led to one explanatory success after another for biologists.

There is the fact that ethologists have had great success in explaining animal behavior using game theoretic models. These are mathematical models based explicitly on the assumption that the behaviors in question evolved via natural selection; the success of the models is evidence that the assumption is correct.

There is the fact that computer simulations based on natural selection, whether in the form of artificial life experiments or genetic algorithms, have shown that prolonged selection leads almost inevitably to complex products.

There is the rich body of mathematical work in population genetics that shows that variations conferring even very small selective advantages on their bearers are likely to spread with sufficient speed and frequency.

Of course, big books get written on any one of these topics. No one familiar with this body of work could possibly write something as dopey and simplistic as what Sewell wrote.

Incidentally, natural selection is not a “force” in the physics sense. That this is the sense he has in mind is suggested by his use of the same word later in the paragraph. It's a small point, but this sort of imprecise writing is common throughout Sewell's essay. It frequently makes it difficult to discern Sewell's intention.

We are next informed that it is only laymen who can see the flaw in the scientist's logic. The professionals, apparently, are hopelessly blind. This is a big litmus test: If the person whose work you're reading tells you that scientists are confused on a point that is clear to any layman, then you are reading the work of a crank. It has never once happened in the history of science that a theory collapsed because a layman pointed out a logical fallacy in its formulation.

Sewell's next claim is that he provided specific reasons in his 2000 article for thinking that natural selection could not craft complex systems. I invite you to follow the link I provided above and decide for yourself whether this claim is true. Be warned, however, that you will have to read his essay very carefully indeed to find anything related to biology in it. Mostly he just relies on the standard bad analogy of genes to computer programs.

After this we get some blather about computers and spaceships and the like. I'll respond to Sewell's point here as soon as I figure out what it is. The issue at hand is whether known natural mechanisms can account for the sort of biologocial systems we see in nature. Certainly once intelligence arrives on the scene it can cause things to happen that would not happen by natural forces alone.

So why is Sewell using the products of human intelligence to illustrate his intention? Is he making some point about free will? In asking how natural forces can cause atoms to arrange themselves into computers and the like, is he suggesting that if intelligence is the inevitable result of evolution then the products of intelligence are similarly predictable? If that is not what he means, then what can he possibly have in mind in asking whether natural forces alone can create computers?

In his 2000 article Sewell made a similar point:


I imagine visiting the Earth when it was young and returning now to find highways with automobiles on them, airports with jet airplanes, and tall buildings full of complicated equipment, such as televisions, telephones and computers. Then I imagine the construction of a gigantic computer model which starts with the initial conditions on Earth 4 billion years ago and tries to simulate the effects that the four known forces of physics (the gravitational, electromagnetic and strong and weak nuclear forces) would have on every atom and every subatomic particle on our planet (perhaps using random number generators to model quantum uncertainties!). If we ran such a simulation out to the present day, would it predict that the basic forces of Nature would reorganize the basic particles of Nature into libraries full of encyclopedias, science texts and novels, nuclear power plants, aircraft carriers with supersonic jets parked on deck, and computers connected to laser printers, CRTs and keyboards? If we graphically displayed the positions of the atoms at the end of the simulation, would we find that cars and trucks had formed, or that supercomputers had arisen? Certainly we would not, and I do not believe that adding sunlight to the model would help much.


After acknowledging that chance plays a major role in the development of a physical system over time (at least at the atomic level), Sewell then asks if a computer would “predict” that Nature would reorganize its fundamental particles in the manner he describes. Just another example of sloppy writing. The relevant question is whether the computer would acknowledge modern civilization as one possible outcome of the initial state of the universe four billion years ago. Sewell has no basis for saying it wouldn't, to put it kindly.

So you see the problem. In responding to Sewell's essay we are confronted with the fact that every sentence, and virtually every clause within every sentence, is total nonsense. It makes it very difficult to understand his argument well enough to compose a reply.

Sewell offers a sulky closing to his essay:


The development of life may have only violated one law of science, but that
was the “supreme” law of Nature, and it has violated that in a most spectacular way. At least that is my my opinion, but perhaps I am wrong. Perhaps it only seems extremely improbable, but really isn't, that, under the right conditions, the influx of stellar energy into a planet could cause atoms to rearrange themselves
into nuclear power plants and spaceships and computers. But one would think that
at least this would be considered an open question, and people who argue that it
really is extremely improbable, and thus contrary to the basic principle underlying
the second law, would be given a measure of respect, and taken seriously by their
colleagues, but we aren't.


Well boo friggin hoo! Maybe Sewell's colleagues don't take him seriously because he accuses them of being blind to logical fallacies that are obvious to any layperson. Maybe they are annoyed that Sewell talks about spectacular violations of the Second Law without performing the sort of entropy calculations that would be required to establish the validity of such a claim. Or maybe they just know enough thermodynamics to understand why Sewell's arguments are totally invalid.

We will have more to say in a future post.

Monday, May 30, 2005

Around the Blogs

My fellow evolutionbloggers have been producing so much great stuff lately, that I think I'll just mooch off them today.

Over at Pharyngula P. Z. Myers has this excellent post explaining why likening various biochemical systems to machines can be a terribly misleading analgy:


Individual proteins do link up to form more elaborate complexes, but still…it's all a function of concentration and reaction rates and binding energies. It's chemistry. It's driven by thermodynamics and equilibria, not guided engineering.

Hmmm. Behe's metaphor isn't a very good one. He wants to pretend something is a “truck”, but when we actually look closely at it, it's a knotty string, a tangle of chemicals. And it isn't driving purposefully around the cell, it's bumping around haphazardly, interacting with other components of the cell chemically. It's also nowhere near as complex as a truck, since the instructions for building one can be reduced to the order you string together a set of pop beads. Using a metaphor can be a useful strategy for getting a point across, but when the metaphor is used to carry a false message, such as the presence of purpose and detailed complexity that is not present, it is actually misleading. When you get right down to it, what's going on inside a cell is about as mindless as soup. (Emphasis in original).


Meanwhile, at the Panda's Thumb Andrea Bottaro reports on yet another nail in the coffin for the argument that complex systems can't evolve.


The topic where the idea of unevolvability of IC systems has probably taken the most beating is the vertebrate adaptive immune system, where not only evidence for evolution has accumulated at a steady pace, but even more embarrassingly for Behe, it has developed exactly along the lines predicted by those “Calvin and Hobbes jumps” he originally dismissed. A recent paper in the journal PLoS Biology [1] is the latest turn in the death spiral of irreducible complexity of the immune system, and I think provides a good opportunity to take a look at how science works, as opposed to ID navel-gazing.


Meanwhile, the Boston Globe weighs in with this strong editorial against ID:


A SELF-INTERESTED New Englander might hope that the Kansas Board of Education comes out decisively against teaching evolution. That would put at least one state at a disadvantage as it competes for biotech business. But the anti-evolution movement, advocating the pseudo-scientific notion called “intelligent design,” is making inroads as far east as Pennsylvania. Only if the concept is rejected will Americans show they are committed to the growth of scientific knowledge


Well said. Sadly, I'm not convinced that Americans are committed to the growth of scientific knowledge.

Sunday, May 29, 2005

ID at the Smithsonian?

Be sure to read this important post from Panda's Thumb contributor Burt Humburg.

It seems that the ID friendly video The Privileged Planet will be screened at the Baird Auditorium of the Smithsonian Institute. This has prompted various ID friendly outlets to blather about how the Smithsonian is warming up to ID. The reality is both predictable and annoying. Here's the money quote from Humburg:


The article explains how the Discovery Institute donated $16,000 to the Smithsonian. In exchange for this contribution, the Smithsonian allowed them to use the Baird Auditorium. And, instead of advancing science or talking about any actual controversy, the DI are playing a video that involved Intelligent Design.

In other words, the DI’s best efforts to get scientific support at the Smithsonian involves payola. They had to pay $16K for the privilege of showing their movie to a hand-picked, 100%-ID-friendly audience at the Smithsonian. Oddly enough, we here at the Thumb think this is the Discovery Institute’s biggest contribution to science in the last decade. It’s also significant that this is in keeping with the Wedge Strategy, gaining notoriety as having their views addressed in academic and scientific venues.


The article being referred to is this one from The New York Times.

This is yet another illustration of something that has been obvious for quite some time now. ID is about money and public realtions. It has nothing to do with science. The Discovery Institute has $16,000 to throw around, and they decided the best use of that money was buy a chance to associate their name with the Smithsonian.

Ask yourself what real scientists would do with $16,000. Do you think that the William Dembski's and Michael Behe's of the world will protest that instead of paying for $16,000 worth of scientific research in ID, the Discovery Institute chose instead to spend the money on a cheap publicity stunt? Does anyone seriously believe anymore that ID has anything to do with science?

Dembski on Orr

Well, not everyone liked Orr's article quite as much as I did. William Dembski has weighed in with this response. It doesn't merit a detailed rebuttal, but there is one point that caught my eye:


This last point about the absence of detailed Darwinian pathways is the Achilles heel of Orr’s criticism of Behe. Orr remarks that “Behe and his followers now emphasize that, while irreducibly complex systems can in principle evolve, biologists can’t reconstruct in convincing detail just how any such system did evolve.” To which Orr immediately adds, “What counts as a sufficiently detailed historical narrative, though, is altogether subjective.” This last point constitutes an damning admission — indeed, it gives away the store. Is Orr saying that evolutionary theory is in the business of telling historical narratives that are purely subjective. If so, how can it constitute a science? And if not, where are the detailed Darwinian pathways that could convince any unbiased bystander that the flagellum really did evolve by Darwinian means? Orr suggests that design theorists are tendentiously raising the bar of scientific evidence for Darwinism too high. But this is not the case. Without detailed, testable Darwinian pathways that produce irreducibly complex systems like the bacterial flagellum, why should anyone believe that such pathways exist at all?


Since this is William Dembski we're talking about, I'd feel cheated if Orr had been quoted accurately. Dembski is deliberately misrepresenting Orr's point. Surprise!

What Dembski is not telling you is that his first quote above comes as the last sentence in a paragraph. The second quote, the one about subjective judgements, is the first sentence of the next paragraph. Someone who, unlike Dembski, actually cares about representing his opponent's views accurately and making a good argument in reply, would have quoted considerably more.

In a moment I'll show you what Orr actually said. But first notice that even the fragment quoted by Dembski is enough to show that Dembski is vamping here. Orr's point is perfectly clear. It is not the explanations themselves that are subjective. After all, any proposed scenario for the evolution of a complex system must be consistent with everything that is known about that system. Each bit of data in that regard is one more test for the scenario to pass.

What is subjective is the judgment of whether the scenario is well-enough supported to be accepted as correct. Contrary to Dembski's bleats, the evidence that complex biological systems are the product of evolution is sufficient to convince just about every scientist who has ever considered the matter. In reply the ID folks simply fold their arms and shake their heads and say they are not convinced.

Now, for what Orr actually said:


What counts as a sufficiently detailed historical narrative, though, is altogether subjective. Biologists actually know a great deal about the evolution of biochemical systems, irreducibly complex or not. It’s significant, for instance, that the proteins that typically make up the parts of these systems are often similar to one another. (Blood clotting—another of Behe’s examples of irreducible complexity—involves at least twenty proteins, several of which are similar, and all of which are needed to make clots, to localize or remove clots, or to prevent the runaway clotting of all blood.) And biologists understand why these proteins are so similar. Each gene in an organism’s genome encodes a particular protein. Occasionally, the stretch of DNA that makes up a particular gene will get accidentally copied, yielding a genome that includes two versions of the gene. Over many generations, one version of the gene will often keep its original function while the other one slowly changes by mutation and natural selection, picking up a new, though usually related, function. This process of “gene duplication” has given rise to entire families of proteins that have similar functions; they often act in the same biochemical pathway or sit in the same cellular structure. There’s no doubt that gene duplication plays an extremely important role in the evolution of biological complexity.


That's the point. There are a variety of natural mechanisms (gene duplication is one of many) that can in principle lead to the evolution of so-called irreducible complexity, and there is considerable evidence that those mechanisms have played out in fact. The idea that we must invoke a supernatural intelligence to explain these systems is ridiculous.

Actually, in reading Dembski's reply I was reminded of this quote, from a previous essay by Orr in reply to a similar point from Dembski:


Dembski’s response is to point out that I have merely shown that IC systems can conceivably be built by Darwinism (a point he does not deny), not that such systems were built by Darwinism or even that they were probably built by Darwinism. I am accused, in other words, of having low standards: “Orr, along with much of the Darwinian community, is satisfied with a very undemanding form of possibility, namely, conceivability.” The problem with this is simple. It was Behe who posed the problem in terms of conceivability versus inconceivability. Behe said that Darwinism could not possibly produce IC systems. Behe spoke of “unbridgeable chasms.” Behe asked, “What type of biological system could not be formed by ‘numerous, successive, slight modifications’?” and then answered, “A system that is irreducibly complex.” The discussion has, in other words, taken the following form:


BEHE: Darwinism can’t possibly produce IC systems.
ORR: Darwinism can produce IC systems. Here’s how . . .
DEMBSKI: Orr has merely shown that a Darwinian explanation is possible. What a risibly low standard!




Well said.

Orr in The New Yorker

H. Allen Orr has a typically excellent article in the most recent issue of The New Yorker. Here's an excerpt:


Dembski’s arguments have been met with tremendous enthusiasm in the I.D. movement. In part, that’s because an innumerate public is easily impressed by a bit of mathematics. Also, when Dembski is wielding his equations, he gets to play the part of the hard scientist busily correcting the errors of those soft-headed biologists. (Evolutionary biology actually features an extraordinarily sophisticated body of mathematical theory, a fact not widely known because neither of evolution’s great popularizers—Richard Dawkins and the late Stephen Jay Gould—did much math.) Despite all the attention, Dembski’s mathematical claims about design and Darwin are almost entirely beside the point.


Exactly right. Dembski's probability calculations are numerology, pure and simple. He assigns numbers to objects in essentially random ways and then hopes, by manipulating the numbers, to learn something about the objects. In reality he is only learning something about the way he assigned the numbers.

And his use of the obscure “No Free Lunch Theorems” are no better. Even the authors of the theorems have pointed out that he's full of it, for heaven's sake!

I also liked this part:


It’s also hard to view it as a real research program. Though people often picture science as a collection of clever theories, scientists are generally staunch pragmatists: to scientists, a good theory is one that inspires new experiments and provides unexpected insights into familiar phenomena. By this standard, Darwinism is one of the best theories in the history of science: it has produced countless important experiments (let’s re-create a natural species in the lab—yes, that’s been done) and sudden insight into once puzzling patterns (that’s why there are no native land mammals on oceanic islands). In the nearly ten years since the publication of Behe’s book, by contrast, I.D. has inspired no nontrivial experiments and has provided no surprising insights into biology. As the years pass, intelligent design looks less and less like the science it claimed to be and more and more like an extended exercise in polemics.


Now go read the whole thing.