Enough Information

2010.10.29   prev     next

HOW much information do we need about a topic before it’s OK to say that this conclusion or that conclusion is warranted? It is with this question in mind that I want to analyze the following quotes from Stephen Barr in his recent debate with Michael Behe:

I’m not here to argue against the Intelligent Design hypothesis. I regard it as a reasonable hypothesis. I’m quite open to the possibility that it may even be the correct explanation of some complex biological structures, though I think it would be extremely difficult ever to prove this. My thesis is that the ID hypothesis, whatever its merits, is not a scientific hypothesis, and therefore should not be taught as such in science classrooms and textbooks. ... If I pay for a science teacher, I expect him to tell me, or my children, how nature works, not his views on ultimate reality or what it all means. The reason that science textbooks and science classes should not talk about God or supernatural causes is very simple: It’s because science textbooks and science classes should stick to their own business.

That’s a convenient way of avoiding the controversy. But you can’t really avoid it, because you still have to decide: If science teachers are not allowed to talk about theories of supernatural intervention, then what should they be saying about the biological structures with which the ID movement concerns itself? Let’s see what Barr has to say about that:

What, then, should be taught in biology classes, according to me, about the kinds of structures that Mike has argued to be irreducibly complex, such as the bacterial flagellum, and so on? The answer, it seems to me, is very simple, and maybe it’s an answer Mike would agree with. If there are structures, such as the bacterial flagellum or the blood clotting system, for which science does not have a satisfactory explanation, it would be entirely proper for a science textbook, or a science teacher, to say exactly that. They could say, for example, “There is much yet to discover about the history of life on Earth, and much that is not fully understood about this history. There does not yet exist a detailed step-by-step of the processes by which certain complex structures evolved, or a full understanding of these processes. Period.” As my favorite new source, FOX News channel says, “We report, you decide.” Let science say, honestly and forthrightly, what it knows and what it doesn’t know.

It would have been really nice if Barr, immediately after advancing the above position, had been asked the following, pointed question: How much information do we have to have about these structures before it will be OK, in your view, for a science teacher or textbook to say: “The evidence strongly indicates that the Darwinian process of random mutation and natural selection did not generate these structures.” Barr’s “There is much yet to discover, and much that is not fully understood” statement certainly implies that he would answer that we would need a lot more information than we have now. But how much more would we need?

Time

Imagine a timeline representing human progress in understanding the bacterial flagellum. It starts with our discovery that there is such a thing as a flagellum (a wiggly, tail-like protrusion that bacteria apparently use to swim), and ends when humanity knows virtually everything about the flagellum, all its parts, how they work, how they’re created, controlled, etc., plus everything about the bacteria that produce and use them. If, in the course of making our way to the end of this timeline, we discover an empirically viable Darwinian explanation of the flagellum, then there it is: Darwin wins.

But supposing we don’t. When we reach the end of the timeline, would it then be OK for science textbooks to say that Darwinian evolution didn’t do it? If not, why not? Does Barr think that the very idea that evolution didn’t generate the flagellum is inherently anti-scientific? In that case, his “much yet to discover” statement is extremely disingenuous. Why not instead tell students that “any idea that mutation-selection evolution didn’t generate a biological structure is inherently anti-scientific,” and see what they think of that? Isn’t honesty a crucial part of science, or does science need to employ a measure of deliberate deception in order to ensure that the correct side wins in a culture war?

Let’s not be that pessimistic. Let’s assume that Barr isn’t as unreasonable or politics-driven as that; let’s assume that he “honestly and forthrightly” would allow an evolution-didn’t-do-it statement into a science textbook if we reach the end of the flagellum-exploration timeline without an improved situation for the claim that evolution-did-it. But, of course, that wouldn’t be today, because we’re nowhere near the end of that timeline.

Then the next logical question for Barr would be: Do we have to know every little thing about the flagellum (i.e. be at the very end of the timeline) before such a textbook statement is permissible? Is there any possibility that we could learn enough about the flagellum to be able to make a statement of scientific confidence that it didn’t evolve — well before reaching the end of the timeline? Or to put it another way, what kind of information would we need to observe about the flagellum to justify an anti-Darwinist position in a science textbook?

I would suggest that Behe’s thesis of irreducible complexity describes exactly the kind of information about the flagellum that we need to make such a justification; that Behe demonstrates that we have now crossed that threshold of knowledge. Today we have enough information to say — with as much scientific confidence as we say many other things in science textbooks which Barr seems to find unobjectionable — that random mutation and natural selection did not generate the bacterial flagellum.

If Barr thinks we’re not at that point yet; if he thinks that Behe’s irreducible complexity doesn’t cut it — well, it would be nice to see him provide some sort of definition of what kind of information about the flagellum would have to be found before he would want science textbooks to doubt Darwinism. Something a lot more specific than “more information than we have now” would be very helpful to anyone who, like me, wants to understand Barr’s position and why he takes it.

Questions

And there are yet more questions Barr leaves unanswered. Would he be OK with a biology textbook having a chapter or section describing Behe’s thesis of irreducible complexity? They could leave out all speculation of what did produce the flagellum, presenting Behe’s position as an argument just that mutation-selection evolution didn’t do it. And if Barr wants them to, they could conclude that section of the book with a disclaimer to the following effect: “Behe’s IC arguments do not absolutely prove that evolution didn’t create the flagellum, because scientific conclusions are always tentative; future evidence may surprise us and reveal a way that random mutation and natural selection could generate these structures.” That might (or might not) placate Barr. But what would students think of it? Would Barr perhaps prefer that the whole subject of IC be omitted from science textbooks, in the hopes that students will think the only problem with flagellum evolution is that scientists “haven’t yet found” the Darwinian steps that produced it?

Barr is trying very hard to find a way to appear simply to be defending the principles and integrity of science as a category of study, while at the same time ensuring that students are presented with a science curriculum that includes no significant doubts about Darwinian evolution. It would be a plenty sad statement about Barr and others of his mindset if the purpose of this curriculum was merely to ensure that students believe evolution is correct. But with the easy availability of books such as Behe’s, and an internet that virtually guarantees that no student of biology will fail to discover Behe’s books — a situation of which Barr is no doubt aware — one can only come to a very much sadder conclusion: Barr’s intent is that the science curriculum make clear to students not that evolution is true, but rather that suggestions that evolution is not true will not be tolerated.

Of course, I don’t know how Barr would answer the questions I have posed above. But based on what he did say, I think it not unfair to summarize his position as follows:

An argument based on evidence; math applied to that evidence; and logic applied to the results of that math — if that argument challenges the assertion that Darwinian evolution is the generator of all of life’s adaptive complexity — belongs in a philosophy or religion class.

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