It's my own fault, really. I wrote a note to a participant in an email discussion group, and failed to remember that it wasn't a closed group. Therefore, writing an off-the-cuff, informal response, I opened myself up to a Bill Dembski snark attack.
So, for the record, here is the full passage that Dembski was responding to (he only quoted part of it):
You’re probably referring to the pseudo-mathematical posturings of William Dembski. Dembski is a fraud whom nobody should take seriously. Here’s why: Dembski’s model of “specified complexity” assumes that when attempting to determine the likelihood of a given pattern coming about randomly, that you have the pattern in mind from the outset. In other words, that evolution is a teleological process. But evolution is not teleological. It is not more unlikely, from a mathematical perspective, that, say, an eye should develop from a process of natural selection than that some other arbitrary result should take place. It’s only mathematically unlikely because you are separating this singular event (i.e., the one that took place), from the billions of other equally singular events that could have taken place, but didn’t. Those events were equally unlikely. prospectively any one of them could have occurred. It’s only retrospectively that we look at the one that did and say it’s unlikely.
Any mathematician worth his salt knows this. Indeed, it’s been pointed out to Dembski. He chooses to ignore it, and that is what makes him a fraud.
Second, on the subject of “chance.” Rhetoric alone is not argument, and accusing evolutionary theories of “linguistic desperation” is not a demonstration that this is what’s going on. I can only assume you mean the arguments of people like Richard Dawkins, who argue, quite cogently, that evolution is not “random” in the same way that say, drawing letters from a bag for scrabble is random. On the contrary, there is a mechanism that governs the process of evolution, namely, adaptation to environment. Variations that contribute to survival (and reproduction) are favored and variations that don’t are disfavored. Evolution is not, therefore, random but follows a comprehensible pattern. But, and this is key, the pattern is not determined by an outside consciousness (at least, from the limited perspective of what science is competent to investigate), but it is determined by the environmental effects on species, their abilities to adapt, and their ability to pass those adaptive qualities on to successive generations.
So you’re right: “chance,” in the scrabble drawing sense, is “preposterous.” It is equally preposterous to propose that this is what evolution theorizes.
Dembski, in his reply, simply accuses me of "ignorance and arrogance," which seems to me to be more evidence that irony is dead. If I had my druthers, none of this would have gone beyond the small group of people in the email discussion where it all began, but alas, that ship has sailed, so I do think I should say a few things by way of response:
- In the first instance, I suppose I owe Bill an apology. It was uncharitable of me to call him a fraud. The possibility exists that, far from being a fraud, he is totally sincere, and completely incompetent. So the choice is really his -- fraud, or incompetent?
- However, that having been said, I don't make any independent claims to competence myself. As several commentators on Bill's blog have noted, my degree is in theology and ethics, not in mathematics. I do claim to have some expertise in philosophy, and have studied a great deal of philosophy of science (particularly with regard to evolutionary theory). I was this guy's student as an undergraduate, and he gave me a pretty good background in philosophy of science regarding evolutionary theory. Nevertheless, I grant outright that Bill could eat my lunch on matters of mathematics.
- I am, however, a "professional amateur" with regard to these kinds of things, and while I wouldn't claim to be able to follow the mathematics in detail, I can certainly understand the issues at stake conceptually. And I've followed a great deal of the debate over this issue. This certainly doesn't qualify me to write peer reviewed articles on the subject, but as an interested lay person, I do have an informed opinion.
- All this being said, I do what any interested layperson does when confronted with an argument that in many ways goes over his head, I consult smart people who know more about the issue than I do. And in that regard, there is certainly no shortage of information.
These things noted, as at least one other commentator on the topic pointed out, I didn't express myself well in my original post. The point I was trying to make (and indeed, that I did get around to making in the portion of the post that Dembski didn't quote), is the same point that H. Allen Orr makes in his critique of Dembski's No Free Lunch:
The problem with all this is so simple that I hate to bring it up. But here goes: Darwinism isn't trying to reach a prespecified target. Darwinism, I regret to report, is sheer cold demographics. Darwinism says that my sequence has more kids than your sequence and so my sequence gets common and yours gets rare. If there's another sequence out there that has more kids than mine, it'll displace me. But there's no pre-set target in this game. (Why would evolution care about a pre-set place? Are we to believe that evolution is just inordinately fond of ATGGCAGGCAGT…?) Dembski can pick a prespecified target, average over all fitness functions, and show that no algorithm beats blind search until he's blue in the face. The calculation is irrelevant. Evolution isn't searching for anything and Darwinism is not therefore a search algorithm. The bottom line is not that the NFL theorems are wrong. They're not. The bottom line is that they ask the wrong question for what Dembski wants to do. More precisely, the proper conclusion isn't that the NFL theorems derail Darwinism. The proper conclusion is that evolutionary algorithms are flawed analogies for Darwinism.
A related point is made by Jason Rosenhouse in his article "Probability, Optimization Theory, and Evolution":
Dembski’s casual approach to probability calculations is fatal to his enterprise. His assertion that CSI reliably indicates design is moot given his inability to establish its presence in biological systems. For example, he accuses Manfred Eigen of making a category error for writing, in reference to understanding the origin of life, “Our task is to find an algorithm, a natural law that leads to the origin of information (Eigen 1992).” Dembski believes organisms possess CSI, which natural laws are fundamentally incapable of producing. But Eigen’s whole point is that genetic information is not complex in the sense Dembski requires. It arises with high probability as soon as certain initial conditions are met.
Moreover, NFL is hardly relevant to Dembski's argument even for the simpler, non-interactive evolutionary algorithms to which it does apply (those where the reproductive success of individuals is determined by a comparison of their innate fitness). NFL tells us that, out of the set of all mathematically possible fitness functions, there is only a tiny proportion on which evolutionary algorithms perform as well as they are observed to do in practice. From this, Dembski argues that it would be incredibly fortuitous for a suitable fitness function to occur without fine-tuning by a designer. But the alternative to design is not purely random selection from the set of all mathematically possible fitness functions. Fitness functions are determined by rules, not generated randomly. In the real world, these rules are the physical laws of the Universe. In a computer model, they can be whatever rules the programmer chooses, but, if the model is a simulation of reality, they will be based to some degree on real physical laws. Rules inevitably give rise to patterns, so that patterned fitness functions will be favoured over totally chaotic ones. If the rules are reasonably regular, we would expect the fitness landscape to be reasonably smooth. In fact, physical laws generally are regular, in the sense that they correspond to continuous mathematical functions, like "F = ma", "E = mc2", etc. With these functions, a small change of input leads to a small change of output. So, when fitness is determined by a combination of such laws, it's reasonable to expect that a small movement in the phase space will generally lead to a reasonably small change in the fitness value, i.e. that the fitness landscape will be smooth. On the other hand, we expect there to be exceptions, because chaos theory and catastrophe theory tell us that even smooth laws can give rise to discontinuities. But real phase spaces have many dimensions. If movement in some dimensions is blocked by discontinuities, there may still be smooth contours in other dimensions. While many potential mutations are catastrophic, many others are not.
Dembski might then argue that this only displaces the problem, and that we are incredibly lucky that the Universe has regular laws. Certainly, there would be no life if the Universe did not have reasonably regular laws. But this is obvious, and is not specifically a consequence of NFL. This argument reduces to just a variant of the cosmological fine-tuning argument, and a particularly weak one at that, since the "choice" to have regular laws rather than chaotic ones is hardly a very "fine" one.
Although it undermines Dembski's argument from NFL, the regularity of laws is not sufficient to ensure that real-world evolution will produce functional complexity. Dembski gives one laboratory example where replicating molecules became simpler (the Spiegelman experiment, p. 209). But it does not follow that this is always so. Dembski has not established any general rule. I would suggest that, because the phase space of biological evolution is so massively multidimensional, we should not be surprised that it has produced enormous functional complexity.
Dembski has replies to several of these objections (here, and here, and here). I leave it to those with more expertise to decide whether he has adequately refuted this critiques. To me, it seems like just so much foot stomping and saying "yes it is so!" rather than advancing any new, and more convincing arguments.
In the final analysis, though, it's not really about whether I find Dembski's work convincing. Neither his arguments nor the arguments of other ID theorists like Michael Behe have found much traction in their respective fields. There is little to no peer reviewed literature supporting their hypotheses, and their very premises have been called into question time and time again by qualified experts in the field. If, in the end, I am wrong, and Dembski is neither a fraud nor an incompetent, I may owe him an apology, but I will at least take comfort in knowing that I will be in the company of a great many eminent mathematicians, statisticians, and information theorists. And, because of that, I remain confident that I have little to worry about.
While more could be said, I would like to address one peculiarity of the remarks made about me by some of the commentators on Dembski's site. There seemed to be an almost obsessive concern with pointing out that I am a mere "professor of religious studies," and not a mathematician. Of course, as I noted above, I plead guilty to the charge. The reason I rely on smart people who know the field better than I do is because, as a mere religious studies professor, I make no claims to the necessary expertise. Nevertheless, given the degree to which Dembski himself, without degrees in biology or biochemistry, relies on his own roster of "smart people" to justify many of the premises on which he bases his probability calculations, I fail to see how he, or his supporters, can claim the high ground on expertise and credentials.
The joy of being a "professional amateur" is that I am not limited in my interests to the things that I have professional degrees in, and I am fortunate to have access to the resources that enable me to stretch my bounds of knowledge into new areas, however tentatively. I'll never write a peer reviewed paper in probability theory, and that's no problem as far as I'm concerned.
But it does strike me that Dembski's arguments, taken cumulatively, amount to saying "my calculations are so complex that only I can understand them!" Certainly the absence of recognition by other experts in the field would lead either to that conclusion, or to the conclusion that his calculations are simply wrong. Yet, if in the end Dembski's agenda is, as it certainly appears to be, to demonstrate the scientific necessity of the belief in God as the designer of the universe, then something is amiss when it is necessary for him to construct his argument in a way that only he, or only he and a few others in the world, could reasonably understand it. "If only you knew the math as well as I do ..." isn't really a compelling reason to believe in his hypothesis.
It strikes me that a truly elegant mathematical breakthrough, something on the order of Godel's Proof, would have the advantage of being so compelling that it would demand the assent of the field of mathematics (as Godel did, but Dembski hasn't), and be explicable to a non-expert such as myself, without a lot of hand waving and pleading, "but the math is too complex." This is why I argue Dembski is an obscurantist. His arguments, no matter how complexly presented, are once more a warmed-over version of the god-of-the-gaps, hidden behind a wall of calculations that make genuine understanding (and critique) impossible. Whatever else it may be, it's not science.