And he is wrong on that claim, both because his "proof" that "current models cannot describe" systems which match his definition is flawed, and because the biological examples he gives don't even match his own definition.
Of course, this is a true statement,
It isn't, I regret to inform you.
which is why there have been two types of responses to Behe: Calling him a nutcase,
"Nutcase" would be overstating the issue, but he definitely shows the signs of what's known as a "crank" -- someone who gets fixated on a favorite alternative theory and has grandiose ideas about revolutionizing science, then clings to it even after flaws in the theory and counterevidence against it have been demonstrated. He even uses the crank's standard "there's a conspiracy against these ideas" excuse for why he has not yet been given the adulation he deserves. Also like the standard crank, he underplays the current body of scientific knowledge, implying that current knowledge is poor or incorrect.
or trying to demonstrate that irreducible complexity does not exist in biological systems.
On the contrary, Behe has not yet demonstrated that any of his examples actually *are* "irreducibly complex" and thus could not have evolved from some earlier system. He waves his hands a lot, but *proving* something "IR" requires far more rigor than just saying, "it seems to me that..."
The critics don't have to prove that no IR systems exist anywhere, Behe has to prove that at least one *does* exist before his arguments will be anything more than a curiosity.
Behe's definition of irreducible complexity has remained consistent (read his book), and so far, the only way people have been able to prove one of his systems reducible is to change his working definition.
See the second half of my previous post -- Behe himself "changes" it by admitting that subcomponents *can* have their own function, which effectively expands his "original" definition in a way that shatters it. Oops.
A definition, by the way, which was NOT arbitrarily obtained. It is a definition that resulted from an OBSERVED weakness in the Darwinian model of natural selection.
This is what Behe would like his readers to believe, but it's not true. One of the most striking differences between Behe's personal definition of "IR" and the statement of Darwin from which Behe claims inspiration:
"If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find out no such case." -- Charles Darwin, "On the Origin of Species"And now Behe's:
"By irreducibly complex I mean a single system which is composed of several well-matched, interacting parts that contribute to the basic function, and where the removal of any one of the parts causes the system to effectively cease functioning."Behe makes a major, glaring error here in trying to "formalize" Darwin's point. By specifying that the key test is whether anything can be "removed" from the system, Behe has artificially constrained evolution to forming new components by only *ADDING* "parts" to pre-existing structures. This is an enormous mistake on Behe's part, because evolution is known to also form novel systems by *removing* parts, or *rearranging* parts, not just adding them -- and Behe's definition of "irreducible complexity" only "allows" evolution to build things by adding.
For illustration, let's say that we find a stucture ABC in a cell. By experimentation, we find that removal of A, or removal of B, or removal of C leaves the structure non-functional in any sense. Aha!, cries Behe, this meets my definition of "irreducible complexity" and thus could never have evolved! Not so fast there, Behe...
First, consider that while we have shown that "AB" was nonfunctional (since ABC was "broken" by our experimental removal of "C"), further examination of component combinations may reveal that "A" by itself is semi-functional, "BA" (not "AB") is moderately functional, and "BAC" is functional. Now note that the allegedly irredicibly complex "ABC" could have evolved after all by the following sequence: A -> BA -> BAC -> ABC (first three steps by addition, last step by rearrangement). Uh oh, Behe seems to have forgotten about *other* methods of "gradual change" reaching the end state, and not just by "adding" things.
Case two: Perhaps instead our examination of the functionality of various combinations of components of "ABC" revealed that *no* combination of one or more of those components, in any order, was in any way functional except for "ABC". Is Behe vindicated in *this* case? No, because Behe has yet again overlooked *another* method by which "ABC" could have arisen "one step at a time". For example: D -> CD -> BCD -> ABCD -> ABC. Ooh, look there -- some *other* component (D), no longer present in the system as we find it today, was the original semi-functional component, upon which evolution built until it happened to end up with a system where "D" was no longer necessary because the rest of the system had developed into a subsystem that shouldered the whole load and no longer needed the original component, so it was discarded.
Yet *again* we find that Behe's simplistic "evolution must proceed only by *adding* components" view leaves out other possible pathways for systems to arise.
By Behe's flawed model of natural gradual change, *this* would be impossible as well and only could have arisen by "intelligent design":
After all, you can't make a sedimentary rock arch by just *adding* sediment, can you?
I spotted this flaw the first time I read Behe's definition of "IR". So did most reviewers. What's Behe's excuse?
So, I hear you ask, hypothetical examples are one thing, but can you point to an example of evolution actually working in those ways? Yes, indeed. There are countless examples in molecular biology, but the most striking ones are (drumroll please) in the cascade systems of the blood clotting and immune complement systems, which Behe uses as examples of irreducible complexity in his book... See:
The Evolution of Vertebrate Blood ClottingBehe basically said: If a system X exists, it cannot have come about through natural selection.Evolving Immunity: A Response to Chapter 6 of Darwin's Black Box
A Delicate Balance, Russell F. Doolittle
Is the Blood Clotting Cascade "Irreducibly Complex?"
Is the Complement System Irreducibly Complex?
Darwin's Black Box: Irreducible Complexity or Irreproducible Irreducibility?
Behe and the Blood Clotting Cascade
Redundant Complexity:A Critical Analysis of Intelligent Design in Biochemistry
A Biochemist's Response to "The Biochemical Challenge to Evolution"
Evolution of vertebrate fibrin formation and the process of its dissolution
Yes, he *said* that -- didn't *prove* it.
He then discovered numerous systems X.
No, he didn't. *Claiming* that numerous systems exhibit property X is not the same as *demonstrating* that they exhibit property X (Irredicible Complexity). Each of Behe's examples boils down to, "wow, this sure is complex, I'll bet that if you knocked out one of its parts, it wouldn't work at all!" Unfortunately for Behe's presumptions, people who *have* done such tests have found that the systems in question are often *not* disabled by removing one or more parts. They're not "IC" even by *BEHE'S* narrow definition.
For example, Behe claims that the vertebrate clotting cascade is "Irredicubly Complex", and he implies several times in his book that if it were missing any component, the animal would either "freeze solid" as all its blood coagulated in its veins, or "bleed to death". Obviously Behe was just GUESSING, because people who *have* actually experimented on removing one or more components of the clotting cascade found that blood clotting often does *not* make it "nonfunctional".
On page 88 of his book, Behe writes the following as part of a passage trying to imply how oh so complex the blood clotting cascade is, and how everything must be "just so" or else it'd fall apart:
Plasmin cannot act too quickly, however, or the wound wouldn't have sufficient time to heal completely. It therefore occurs initially in an active form called plasminogen. Conversion of plasminogen to plasmin is catalizyed by a protein called t-PA. There are also other proteins that control clot dissolution, including alpha2-antiplasmin, which binds to plasmin, preventing it from destoying [sic] fibrin clots.Wow, sounds impressive. The implication that Behe wants to leave is that all parts of the clotting system are "critically" necessary, and that therefore the blood clotting cascade is "Irreducibly Complex".The [Rube Goldberg] cartoon machine that conked Foghorn Leghorn depended critically on the precise alignment, timing, and structure of many components. If the string attached to the dollar bill were too long, or the cannon misaligned, then the whole system would fail. In teh same way, the clotting cascade depends critically on the timing and speed at which the different reactions occur. An animal could solidify if thrombin activated proconvertin at the wrong time; it could bleed to death if proaccelerin or antihemophilic factor were activated too slowly.
Except that they not all of them are, and therefore it isn't.
For example, although Behe specifically mentions t-PA (see above) in his long list of "wow, there sure are a lot of reactions involved", and the way he describes it, t-PA *must* be present to catalyze plasminogen into the critical plasmin, researchers have developed a "knockout" mouse (i.e., a strain of mice with a specific gene knocked out of their DNA) which ENTIRELY LACKS t-PA, and the results on clotting are... noticeable, but minimal. The mice are listed as having normal fertility, and some impairment of clot lysis (dissolving), but otherwise do well enough to to be listed in bioscience.org's category of "GENE KNOCKOUTS WHICH ARE COMPATIBLE WITH VIABILITY" -- i.e., do not manifest a serious rise in mortality rates.
Even knocking out *both* t-PA and the related u-PA, the most noticeable effect on the mice is a 26% reduction in ovulation rates, which isn't good but it still allows the mice to live and reproduce, so their clotting systems are still hardly "nonfunctional".
So the vertebrate blood clotting system is *not* "Irreducibly Complex" after all, not even by Behe's definition -- part of it can be removed and it still functions as a working blood clotting system.
This is just one example of how Behe *guesses* as to whether his sample systems are truly "IC" or not, instead of having proven that they are. In short, Behe was mistaking his presumptions for reality.
That's a point many people fail to recognize.
If anyone's missing a point, it's Behe.
It just isn't the flagellum. He also cites gated transport systems, mammalian blood clotting and a few others that escape me at the moment.
*cough*. See above. Behe's other examples have similar flaws.
The reason that Behe publishes in the creationist papers and sites, is because they are the only ones that will accept his work,
...because they're flawed, but the creationists don't notice/mind because he provides apparent "support" for their preferred conclusions.
despite the fact that his theoretical models and arguments are sound and supported.
You really ought to read some of the actual scientific literature, and not just the pat-each-other-on-the-back creationists sources.
I don't wonder that he's become slightly bitter toward the evolutionist crowd of late.
That's what eventually happens to most cranks who refuse to face the flaws in their work and instead blame the lack of acceptance on a "conspiracy of silence" from "the establishment".