it comes in pints?

Intelligent Design II

Continuing the "discussion from yesterday...

I don't want to belabor the mousetrap analogy because I think it's overblown by both sides. However, I do want to note that the concept of irreducible complexity seems fundamentally flawed because it ignores the fact that most living systems have multiple redundancies, leading to flexibility. A truly irreducibly complex system has become specialized - it can't be simplified without destroying its function but this doesn't mean that its precursor system was so specialized.

A generalization may be made about living organisms (it may not be true in every case, but certainly seems to be a good rule of thumb): More specialized organisms tend to be better adapted to their local environments, but less specialized organisms are more likely to survive changes in the environment. Simplifying a particular system (the blood clotting cascade, for example) may have a selective advantage, but it leaves the system vulnerable to small changes ("breaking the link"). In contrast, a less specialized system is not so vulnerable.

What does this mean for "irreducibly complex" systems? It means that an "irreducibly complex" system, in Behe's formulation, could not have evolved directly from a simpler system. But such a specialized system may, and very likely did, evolve from a less specialized precursor. To take the example of blood clotting, each of the proteins in the cascade is a highly specific protein. But, and this is key, it is not strictly true (as we are led to believe in undergraduate biochemistry) that specific proteins do specific things and that nothing else does them. Different organisms may have different versions of the same protein, with similar but not identical efficiencies, and even the same protein may have multiple functions. To state that because clotting proteins are too specialized to be added to the clotting mechanism ignores that there can be, and are, less specialized versions of the same proteins and even less specialized versions of the clotting system.

It also means that Behe's description of the clotting cascade as "irreducibly complex" is, in fact, a contrived oversimplification of the system because some of the clotting factors actually operate at multiple points in the cascade. (If it sounds like I know something about the clotting system, it's because I do; not enough to be an "expert" but more than the average bear).

Returning to Bryan's post:

ID is in large part an expression of Darwinian thinking's weaknesses...

Not really. I think it's an expression of a desire to keep God involved somehow, some way.

Let's stop here for a moment and discuss something I was going to save for the end of the post but I think needs to go here. People tend to talk about "Darwinism" as if it were some well-defined, monolithic theory. It's not except, perhaps, in Darwin's original statement of the theory. But that statement was a starting point and has been kicked around, restated, extended, massaged, revised, and debated for a century and a half. The term itself is not useful (except as a vague reference to some non-specific evolution involving natural selection) without far more specific information.

Likewise, it seems that people mean different things when they talk about ID. I confess, I haven't read much by its supporters but what I have read suggests that they don't agree on what it means. What exactly does it mean? Does it refer to Thomas Burnet's Universal Clockmaker (as Andrew mentioned yesterday)? Does it mean that nature runs its course but with a helping hand at some points by a benevolent Deity? Does it refer to continual and deliberate creation and destruction of each species over the past 3.5 billion years? Does it refer, as I suspect it does for many adherents, to the Creation story as described in Genesis?

It is impossible to consider ID in any kind of scientific context without defining it specifically (there are other reasons, too). Have any of its adherents articulated what they mean by it? None have in what I have read. They refer to it as they refer to "Darwinism" - as if everyone knows exactly what they mean without defining it further. But in any of its potential meanings, ID has its own weaknesses.

If it refers to the biblical story of Creation, it is directly contradicted by the evidence (Duane Gish's personal crusade notwithstanding).

If it refers to the Universal Clockmaker (Burnet: "We think him a better artist that makes a clock that strikes regularly at every hour from the springs and wheels which he puts in the work, than he that so made the clock that he must put his finger to it every hour to make it strike...") then it requires evolution (not necessarily Darwinian) ever after. That is, unless one is so deterministic that all future organisms were pre-determined by the very act of creation.

If it refers to continual creation, then one must be prepared to accept that all species that ever existed were designed and created individually at different times in history; that they were designed such that later species tend to bear a great resemblance to earlier species (that aren't related, though they look like they should be); that the Creator seems to have been learning as he went along; and that He seems to have been one hell of a prankster, with a mean streak and a poorly developed sense of humor.

Skipping over some ad hominem material in Bryan's post, we get to:

TELL YA WHAT: I'd be more than happy to meet the libertarians more than halfway on this. I'm not a young earther, so teach astronomy as is, Big Bang and all. Do work in a mention of Einstein's reaction upon first hearing evidence that the universe is expanding (he didn't like and started fudging his work to counter it). Teach that stars form from great clouds of gas and dust in a process that takes millions of years--because they do, and the process actually takes that long. Teach that the Earth is about 5 billion years old, because it is. Teach that our Sun is probably a second generation star, formed after the first generation of massive stars blew up and seeded the universe with the metals and elements needed to become planets and living things, because all of that is true.

Bryan just got kicked out of the Creationist club with that paragraph. What surprises me is how many people can accept all of the foregoing, yet not accept that evolution (not even necessarily referring to a Darwinian-type evolution) occurred. I understand Creationists - they've got a story and can't deviate from it. But I don't understand how people need a Creator that continually tinkers with the Universe, or at least with organisms on Earth. Evolution (Darwinian or otherwise) says nothing about the existence of God or the role of faith - let that be my own little caveat for the libertarians. It only says that Genesis is not a biology text (or a geology text, for that matter).

When it comes to biology, don't mention ID. At all. Don't mention it. Just mention two other things, only one of which has anything to do with ID. That would be irreducible complexity. Explain it, even if in doing so you mandate in your textbooks that you scoff at it. Trot out a couple of examples of it. Michael Behe will be happy to supply you with a couple dozen.

Well, Behe seems to have been pretty well rebutted by others, but I don't have too much problem with mentioning irreducible complexity as a potential issue with Darwinian theories. I will point out, however, that for less advanced science classes one should always teach the prevailing orthodoxy even if there are reasons to be skeptical. Even if one doesn't accept the prevailing orthodoxy, it is irresponsible not to teach it. Why? Because no scientific theory has ever been overturned by someone who didn't understand it. Period. And despite the numerous scientific revolutions in history, for every successful overthrow of scientific orthodoxy there were hundreds of unsuccessful attempts. There is a reason theories become orthodoxy - because they worked and they worked well. The odds against overthrowing a successful theory are great, even with strong evidence - Huxley's "nasty little fact" is just a myth. Even strong evidence usually isn't enough; a successful theory can really only be replaced by a better theory [sidebar: even unsuccessful theories can be extremely valuable; much of what we know about the inner workings of stars came from scientists attempting to disprove the Big Bang model in favor of Steady State].

Also, mention punctuated equilibrium. Explain it. Give one or two examples of why biologists have come up with the term and what it's supposed to explain.

Yes, please do. It's a fascinating and (I think) valuable contribution to evolutionary work.

Actually, I'm not exactly sure why Bryan mentioned it. Some creationists have attempted to paint Stephen Jay Gould as anti-Darwinian because he was a proponent of punctuated equilibrium, which they mistakenly thought was an anti-Darwinian theory. It's not, although it is in conflict with the strictest formulation of Darwinism, that of slow evolutionary changes in large populations.

I suspect, rather, that Bryan means it's an ad hoc response to seemingly abrupt changes in the fossil record. There may be some truth to that; I don't know enough about the earliest history of the theory to be sure. But one can start with other knowledge of population genetics and argue logically to arrive at a punctuated equilibrium model so I don't believe possible ad hoc origins would detract much from its usefulness.

THE POINT IS that science is a human pursuit. As such, it is subject to the same foibles, nobility, factionalism, dishonesty and even heroism as any other human pursuit. And established science often turns out to be entirely wrong.

Absolutely! The history of science is full of examples. But don't forget, as I said above, that successful theories are successful for a reason. They are right more often than not and it's rarely wise to bet against them without some strong medicine and another good theory in your pocket.

"Science" isn't some monolithic group of savants who reveal to us approved knowledge and protect us from forbidden foolishness. "Science" is a collection of smart, ambitious people out to prove something or disprove something else. Egos clash. Arguments ensue. Ideas compete to the death.

That is science--the constant competition of, refinement of, discarding of and creation of ideas

Yeah, ain't it grand?

But this actually contradicts one of Bryan's main contentions: that the "scientific establishment" is trying to suppress anything that contradicts Darwinism. It just isn't so. I guarantee that the person who overthrows Darwin will be as famous as Darwin himself and there is no lack of enthusiasm for becoming one of the most famous names in history. But probably very few people, certainly among those who know enough about the field, actually have any illusions that they will do so with the current state of knowledge and without a complete and logically consistent theory to replace it. As Gould said, I suspect we'll have Darwin to kick around a while longer.

Posted by Ken S at August 5, 2005 04:15 PM | TrackBack (0) |