Bryan Preston at Junkyardblog has a post up about evolution called "What Are You So-called Libertarians Afraid of?", in which he tries to demonstrate why Intelligent Design should be taught in schools. He rightfully excoriates libertarians and others who went overboard about Bush's statement on ID.
Some others have also responded, some hostilely. I won't address them today, but Bryan was (mostly) measured and (mostly) not-too-awfully-hostile.
In fact, I almost agree with Bush's actual statement, not the media description that most people seem to be offended by (my emphasis to show why I almost agree):
THE PRESIDENT: Then, I said that, first of all, that decision should be made to local school districts, but I felt like both sides ought to be properly taught.Now, that doesn't really say he "accepts the validity" of ID, but that it should be "properly taught" in the context of understanding what the debate is about. Well, maybe, with the understanding that "properly taught" means "this is why the vast majority of biologists reject it".Q: Both sides should be properly taught?
THE PRESIDENT: Yes, people -- so people can understand what the debate is about.
Q: So the answer accepts the validity of intelligent design as an alternative to evolution?
THE PRESIDENT: I think that part of education is to expose people to different schools of thought, and I'm not suggesting -- you're asking me whether or not people ought to be exposed to different ideas, and the answer is yes.
Anyway, it's a mostly non-snarky post (and I will attribute the limited snark to irritation at the vitriol dispensed by many others) so I will attempt to answer him respectfully.
First off, Bryan makes a fundamental mistake made by many on both sides of the aisle: thinking the word "evolution" is synonymous with "Darwinian evolution". One big problem with this is that critics believe that disproving Darwinian evolution disproves evolution in any form (it doesn't); the second biggest problem is that it doesn't address two completely different meanings of the word as it is currently used.
The first meaning is the simple fact of evolution: it is observed that, at different times in history, entirely different populations of life have inhabited the earth and that subsequent forms tend look a hell of a lot like the ones immediately before (or even continuing to live concurrently). This is so well documented that it is "fact" the same way the "all objects denser than air fall when dropped" is fact -.the evidence is overwhelming.
The second meaning is the theory of evolution: the mechanisms of how and why it happens. Darwinian theory falls in this category but again, it's not synonymous. There have been many theories suggested. Lamarck's is probably the most widely known of the non-Darwinian models; Darwin's grandfather Erasmus Darwin had another (dispelling the common notion that Charles Darwin "invented" evolution). Darwin's great contribution lay in the concept of natural selection as the agent of change in populations, a concept which did not win full acceptance even among biologists until the 20th century (and not in the Soviet Union until the 1960s).
Even disproving Darwin completely as to how evolution occurred does not dispute the fact that it did. Newton's theory of gravity can be completely wrong but that doesn't mean there is no gravity.
Moving on: Bryan seems to attribute the attitudes of libertarians to anti-Christian bias:
I wonder--do they realize that they're acting like totalitarians? Do they even care? Nah. They just want to ridicule anything with even a whiff of Christianity about it.This is an understandable reaction, given the rather vicious anti-Christian attitudes in some quarters (attitudes which irritate me, too) but ID is not a "Christian" concept, unless one equates Christianity with fundamentalism and even then ID is little more than a poor stepchild to creationism. Does anti-religious bias explain why scientists don't want ID taught as if it were an acceptable alternative to evolution? Well, no. We are simply sick of having to rehash the same old arguments which were dealt with decades ago. It has nothing to do with Christianity (or even non-Christian religions) and everything to do with refusing to give "equal time" to inferior "theories". If Immanuel Velikovsky had adherents attempting to get his nonsense taught in schools, we would be fighting it just as hard and mocking them just as vehemently (at least those of us who remember him).
The fact is, though, no matter which side of this particular debate you're on, the libertarians are in fact shouting for the suppression of ideas. They are shouting, in their ignorance of what the president actually said, for the closing of minds...And here I was thinking that individual freedom to explore any idea was what jazzed libertarians up.Again, no. We are not suppressing ideas. That does not mean that all ideas are equally deserving of being taught in school, particularly in a science class. By all means, talk about the problems with the prevailing orthodoxies. Fully consider the limitations of current theory. Bring up alternative theories that are under serious consideration. But don't try to claim that discredited theories dressed up in new garb are equally valid. And, for God's sake, please don't be so arrogant as to insist that your creation story, despite it's fatal flaws as a scientific model, is the only creation story worthy of consideration in public schools.
Now, on to substantive criticism.
The fact is, Darwinian evolution has some weaknesses...No quibble there, especially if we're talking about strict Darwinism. That's why there is vibrant debate among biologists about it. There are widely ranging opinions about how evolution proceeds, the actual mechanisms and rates, how behavior may be controlled or influenced by genes, how large a role natural selection plays, even about what level evolution works on. Does it only work on individual organisms? Species? Or, in Samuel Butler's aphorism a century before Richard Dawkins, is the hen just "an egg's way of producing another egg"? These debates can be every bit as acrimonious as the debates between scientists and creationists. But no serious biologist disputes that evolution happened, and probably none dispute that the core ideas of Darwinian theory are correct even if its strict formulation is not (and I don't think the strict formulation is correct; at the very least, it isn't a complete description).
...the best known and researched of these being something called "irreducible complexity." Some systems in nature have to have all their various parts in order to function, a lack of function leads to death for the organism that uses them, and therefore Darwin doesn't adequately address how they might have formed.This is simply incorrect. I will state up front that I haven't read Michael Behe's books but I've seen some of his examples and I am not impressed with his arguments. His example of the mousetrap, aside from being a prime example of the dangers of arguing by analogy (a trap Darwin sometimes fell into also), is easily dispensed with by successively simplifying it (so much for "irreducible"): it consists of five parts: a wooden base, a metal hammer to hit the mouse, a spring to drive the hammer, a metal bar to hold the hammer, and a catch to be tripped.
First we get rid of the base and just set the rest on the floor. Only four parts.
Next, get rid of the spring. A heavier hammer can be driven by gravity. Three parts.
Make that two parts: the bar and the catch can be combined, leaving the hammer and the catch/bar.
That leaves a fully functional, if less efficient, mousetrap in a form usually called a "deadfall" trap.
Even if one then tries to argue that it has now been reduced to "irreducible complexity", it misses a fundamental point. Even a truly "irreducibly complex" system is only "irreducibly complex" in its current form, and that form says nothing about its previous history (which may have been more complex) or the pathway by which it came to be. Assuming that it had to evolve from a similar system with one less part but with all other parts essentially identical is simply incorrect. His examples of clotting systems and immune systems are flawed the same way: breaking one link may break a chain but only because the chain is in its current form, and that doesn't mean there aren't shorter or simpler or even more complex chains.
I'm reminded of Darwin's (at least I think it was Darwin) own lack of imagination when he said "What good is five percent of an eye?" He missed the obvious (to me, at least) answer: "It's better than four percent of an eye".
This is getting overly long, so I'll cut it for now and try to add some more tomorrow.
Posted by Ken S at August 4, 2005 04:47 PM | TrackBack (0) |Perhaps it's the possibility of raising kids who are content with the answer "God/Creator/Divine Architect made it happen" rather than digging deeper and trying to unlock the mysteries of the universe.
Or because we suspect that ID supporters are primarily interesting in using ID to wedge open the door so that full blown creationism can step in.
To use an analogy, do you think that vocal gun control advocates who support registration of handguns don't have their eyes on confiscation down the road?
Posted by: Bill McCabe at August 4, 2005 09:06 PMBehe's illustration is useful in getting the layman to understand the concept of irreducible complexity. His detailed explanation of the mousetrap analogy is here. His chief observation is that mousetrap evolutionary models (his own and those proposed by his critics) always involve some step that requires two or more simultaneous changes.
Google "behe flagellum" for takes on his real-life example of irreducibly complex biological systems. (I'm surprised at how few results the search produces.)
Posted by: Alan K. Henderson at August 4, 2005 10:20 PMIntelligent design sounds rather similar to the Deist belief in so-called (by its creationist critics) "clockwork theory". Can someone explain to me how they differ? Surely intelligent design is preferable to the literalist tradition pushed by fundamentalists.
Posted by: Andrew Ian Dodge at August 5, 2005 05:19 AMAndrew, I will be writing more on that today (time permitting).
Extremely brief version: ID has to work one of two ways (as I see it): either the clockwork model (which requires subsequent evolution, Darwinian or otherwise) or continual creation of each new species.
Alan, I printed out Behe's defense of the analogy and will read it shortly.
Bill, for me it's both. I suspect that most ID supporters are not trying get full-blown creationism in the schools but the movers and shakers are (just like most gun control supporters don't support full-blown confiscation but much of the leadership does)
Posted by: Ken Summers at August 5, 2005 06:29 AMI read Behe's defense. It looks to me like he is misstating some of the steps as "too complicated" when in fact they are not. The complicated steps can be replaced by a much longer series of smaller steps, each of which is functional.
Again, it illustrates the dangers of arguing from contrived examples (but I accept and respect his explanation of why it was chosen). The problem arises because he tries to generalize from a contrived example to natural systems, but that's not justified.
At one point, at least, his argument seems to boil down to "an intelligent person imagined this particular step, therefore it must have happened because of intelligence". You can't start with an intelligently designed analogy, push it through intelligently designed steps, then complain that its being intelligently designed invalidates it.
He also attempts to argue the fallacy that the liklihood of one particular pathway is too low to have happened. There's probably a fancy name for this but I'll call it the lottery fallacy: any particular outcome is not likely but there must be some outcome.
Anyway, I'll drop it. I do think both sides seem to have gotten too serious about this particular example.
Posted by: Ken Summers at August 5, 2005 07:49 AMThe thing that baffles me about evolution the most is the lack of a cogent explanation for a nonintelligent source of coded information.
The explanations I run across seem a lot like this cartoon. Here's an example. There is a species of wading bird without feather waterproofing, that stands still with wings spread apartt to dry off. It can do so because it has no predators to contend with. A guest lecturer who appeared at the University of Texas at Arlington in 1990 (give or take a year or two) said that similar un-waterproofed birds evolved waterproofing when predators showed up.
By what mechanism? How does the genetic code alter itself based on information gathered through the bird's senses of sight, sound, and/or smell?
(The senses involving physical contact with the predator would not apply, as the bird would become lunch and therefore not pass on its genes.)
I have an alternate explanation, my "Flight From The Inner City To The Suburbs" theory of the origin of un-waterproofed water birds. Those with and without the water-repelling oil glands appeared at the same time, and the latter (those that didn't get eaten first) simply migrated away from the predator-rich environments.
In a completely different frame of mind, maybe we could make use of evolution against the enviro-whackos. "Human presence won't kill off endangered wilflife. They'll adapt to us. Why, spotted owls - that could live only in old-growth forests as late as the Reagan administration - have evolved to thrive in K-Mart signs!
Posted by: Alan K. Henderson at August 5, 2005 10:55 AMLiving in a K-Mart sign? Talk about your endangered species!
For many of the specific issues in how strange structures evolved, I highly recommend Stephan Jay Gould's books (especially the ones before he overpowered his editors). No one I've read has been able to explain difficult and complicated evolutionary issues to non-experts as well as he did.
For cases like the waterproof birds, it helps to keep in mind that most populations have a great variation in genetic raw material to work with, and that differential survival of offspring is a key concept. If predators ate a large fraction of the bird population in a short space of time, the species would probably just become extinct (as happened when North American predators entered South America after the Isthmus of Panama rose above sea level).
But if birds stuck to the water to avoid predators (and didn't bother to dry off, or even just became quicker to avoid them while drying), then any slight increase in waterproofing becomes a selective advantage and their offspring will survive in slightly larger numbers. Continued pressure over many generations would gradually build completely waterproofed birds.
I don't know about the specific birds or the lecturer, but it is also entirely possible (in the absence of any fossil evidence) that the lecturer has it exactly backwards - that all the birds were waterproof and a particular species living without predators lost the waterproofing because there was no selective pressure for it; conceivably, there could even be pressure against it (though I don't know what that would be).
Posted by: Ken Summers at August 5, 2005 11:53 AMI don't think that evolution is an observed fact, Ken.
We observe that there are different species now. We observe, as you say, that there have been species like them previously, and what we take to be a chain of them, slowly changing over time.
That is exceedingly good reason to think that evolution has occurred, but it is not observed or fact; the fossil record is the fact, and evolution is by far the most likely and strongest explanation of the record.
But evolution itself is not a fact; it's a very, very strong hypothesis explaining the fact of the fossil record.
Posted by: Sigivald at August 5, 2005 02:44 PM