Paul and Paul: Thanks for your responses. I haven't done a whole lot of reading on this issue but am probably as informed (or uninformed) as the average psychologist. However, I have heard that some intelligent design theorists make a distinction between macroevolution and microevolution. As I understand it, macroevolution is any evolutionary change at or above the level of species and refers to the change of one species to another species. Microevolution is any evolutionary changes within species and refers to changes in the frequency within a population or a species of its alleles and their effects on the form, or phenotype, of organisms that make up that population or species. Perhaps macroevolution could be described as between-species evolution and microevolution as within-species evolution. My understanding of it is that intelligent design theorists agree that microevolution occurs, but do not believe there is sufficient justification for macroevolution. Is this also your understanding of the intelligent design position? How would you respond to that position?
Rod ______________________________________________ Roderick D. Hetzel, Ph.D. Department of Psychology LeTourneau University Post Office Box 7001 2100 South Mobberly Avenue Longview, Texas 75607-7001 Office: Heath-Hardwick Hall 115 Phone: 903-233-3312 Fax: 903-233-3246 Email: [EMAIL PROTECTED] Homepage: http://www.letu.edu/people/rodhetzel -----Original Message----- From: Paul C. Smith [mailto:[EMAIL PROTECTED]] Sent: Thursday, March 21, 2002 8:56 AM To: Teaching in the Psychological Sciences Subject: RE: Creationism as Science?? Rod - "Expertise" is FAR too strong a word <grin>. I'm not a biologist of any sort, nor an expert of any sort on evolution, though I do have enough understanding to see through the transparent creationist objections (it doesn't take much for that). A good starting place is always alt.talk.origins. Here is the entry page to their work on "irreducible complexity": http://www.talkorigins.org/faqs/behe.html Here's an example, by H. Allen Orr: http://bostonreview.mit.edu/br21.6/orr.html ======================== (beginning with a piece that Mike quoted...) So the question facing biologists is clear: Do irreducibly complex systems represent an unbridgeable evolutionary chasm? If so, Darwinism is in a bad way and Behe has made an astonishing discovery. If not, Behe's case collapses and he has succeeded only in misleading large numbers of people. Behe, never shy, has already cast his vote: the discovery of design, he assures us, is "so significant that it must be ranked as one of the greatest achievements in the history of science," rivaling "those of Newton and Einstein, Lavoisier and Schrodinger, Pasteur, and Darwin." Reducible Complexity The first thing you need to understand about Behe's argument is that it's just plain wrong. It's not that he botched some stray fact about evolution, or that he doesn't know his biochemistry, but that his argument-as an argument-is fatally flawed. To see this we need to first get clear about what kinds of solutions to irreducible complexity are not open to Darwinism. First it will do no good to suggest that all the required parts of some biochemical pathway popped up simultaneously by mutation. Although this "solution" yields a functioning system in one fell swoop, it's so hopelessly unlikely that no Darwinian takes it seriously. As Behe rightly says, we gain nothing by replacing a problem with a miracle. Second, we might think that some of the parts of an irreducibly complex system evolved step by step for some other purpose and were then recruited wholesale to a new function. But this is also unlikely. You may as well hope that half your car's transmission will suddenly help out in the airbag department. Such things might happen very, very rarely, but they surely do not offer a general solution to irreducible complexity. Behe's colossal mistake is that, in rejecting these possibilities, he concludes that no Darwinian solution remains. But one does. It is this: An irreducibly complex system can be built gradually by adding parts that, while initially just advantageous, become-because of later changes-essential. The logic is very simple. Some part (A) initially does some job (and not very well, perhaps). Another part (B) later gets added because it helps A. This new part isn't essential, it merely improves things. But later on, A (or something else) may change in such a way that B now becomes indispensable. This process continues as further parts get folded into the system. And at the end of the day, many parts may all be required. The point is there's no guarantee that improvements will remain mere improvements. Indeed because later changes build on previous ones, there's every reason to think that earlier refinements might become necessary. The transformation of air bladders into lungs that allowed animals to breathe atmospheric oxygen was initially just advantageous: such beasts could explore open niches-like dry land-that were unavailable to their lung-less peers. But as evolution built on this adaptation (modifying limbs for walking, for instance), we grew thoroughly terrestrial and lungs, consequently, are no longer luxuries-they are essential. The punch-line is, I think, obvious: although this process is thoroughly Darwinian, we are often left with a system that is irreducibly complex. I'm afraid there's no room for compromise here: Behe's key claim that all the components of an irreducibly complex system "have to be there from the beginning" is dead wrong. ======================== In short, one of the problems with the Irreducible Complexity argument is that it falls prey to the seductive notion that natural selection is teleological - that it "aims" in some manner towards some not-yet-achieved goal. It's not surprising at all that creationists would find that a natural assumption, of course, and the general anthropomorphic arrogance ("if it's complex, it must have been the product of someone like us") that we all seem to share adds to the seductiveness of the argument, and the blinders to the real claims of evolution. That's only one example that I can retrieve while sitting here, but I have recently read others elsewhere from the usual "big names" (Gould, Dawkins). They're not hard to find, and I'm quite certain that Gould's new tome covers it. Paul Smith Alverno College Milwaukee --- You are currently subscribed to tips as: [EMAIL PROTECTED] To unsubscribe send a blank email to [EMAIL PROTECTED] --- Incoming mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.325 / Virus Database: 182 - Release Date: 2/19/2002 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). 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