Irreducible Complexity Still Not Disproven… Wait, What?
The story so far:
Back in 1996, when Intelligent Design was in its infancy (and pretty
much indistinguishable from today’s Intelligent Design), Michael Behe
defined an irreducibly complex system as:
composed of several well-matched, interacting parts that
contribute to the basic function, wherein the removal of any one of
the parts causes the system to effectively cease
functioning.
Recently, the Disco Tute
presented the bicycle
as an example of an irreducibly complex system, on the grounds that if
you remove one of the wheels, it doesn’t work anymore.
Carl Zimmer
responded
with a video of someone riding a bicycle with only one wheel. So
presumably bicycles aren’t irreducibly complex after all.
Now DonaldM at Uncommon Blithering
presents
this bizarre counterargument:
if you look closely at the photo you’ll notice it isn’t
just the front wheel that’s missing from this bicycle, but the entire
front wheel assmembly, including the handle bars and wheel
frame.
So, um, I guess the point is that if you remove exactly one part from
an IC system, it doesn’t work, but you can remove a whole bunch of
parts from an IC system, and it still works. Wait, what?
Elsewhere in the same post, Donald asks:
Perhaps the good Dr. Z would be so kind as to provide a
bibliography listing all the peer reviewed scientific research studies
that provide the detailed, testable (and potentially falsifiable)
biological models for any of the IC systems that Mike Behe
described in his ground breaking book Darwin’s Black
Box.
Might I suggest that Donald start with the articles and books about
blood clotting and the human immune system that were literally piled
up in front of Behe on the witness stand at the Dover trial? There’s a
good boy.
I’d like to remind him that “nuh-uh” is not a rebuttal.
Unfortunately, I suspect that we’ll be stuck with irreducible complexity for the foreseeable future. It’s just too easy to move the goalposts. The only way to stomp it out is to exhaustively refute every member of the infinitely large set of possibilities. Even if they did manage it somehow, the argument would shift from, “You can’t explain how this could have happened,” to, “Well, it could have happened that way, but that’s a just-so story!” The observant reader will note that Behe happily does this fairly regularly.
I’ve never managed to get my head around why IC is so appealing. Even if we assume that there are systems with N parts that cannot function with N – 1 parts, that doesn’t mean that such a system can’t be constructed from a system of N + 1 parts which in tern came from a non-IC system. It’s like seeing a climber who has climbed himself down a cliff face and gotten stuck and assuming that he can fly because there’s no path up to where he is.
Also, I’m not much of a CS/math guy, but IIRC, formally proving programs and the like to be “minimal” is a pretty damned difficult thing to do anyway. I would think that proving something “irreducible” would be a similar burden.
You’re right, of course, but that doesn’t mean we can’t mock the IDiots.
Well, it does make sense, at least theoretically: if it’s possible to demonstrate that there’s no way to get from A to B by some mechanism X, then it’s logical to conclude that X does not explain the transition from A to B.
As you point out further down, actually demonstrating it is trickier than it sounds, but the general outline is sound.
I think you’re talking about Gothic arches, right? An arch is an IC system: each stone helps prop up the entire structure, and if you remove any stone, the whole thing collapses. And, per Behe’s argument, it’s impossible to build an arch by adding one stone at a time.
So the way to build an arch is to build a scaffolding that’ll keep the incomplete arch from collapsing. Once the last stone is in place, you remove the scaffolding.
Pretty much, yeah, as I recall. I remember seeing a few such proofs in math class, and thinking that they were rather beautiful. I’ve heard of similar things in engineering, where there’s a formula describing the most efficient steam engine possible, or something like that. The person who told me about this said the math wasn’t 100% certain the way that mathematical proofs are, but is based on some very reasonable assumptions.
The flaw (or one flaw) with Behe’s argument is that he simplifies the problem in order to make it solvable: he says that if you remove any part of the bacterial flagellum, it no longer functions as a flagellum. But what he needs to demonstrate is that if you remove any part of a flagellum, it no longer functions as anything (or rather, isn’t something that could have been selected for).
And that is much, much harder to show. Kind of like demonstrating the absence of a leak in a tire, without actually immersing it in water.
True, you can’t remove a single stone from a Gothic arch without collapsing the structure, but before there were Gothic arches, there were Romanesque ones. Therefore you can ride a bicycle with the front wheel removed, bacterial flagella have precursors, evolution is a fact, and Behe is an idiot. Wait, what were we talking about again? Never mind, my argument makes no less sense than anything the DI has put out there. 😉
Thanks, Arensb, for continuing to advance the cause of rationalism! Happy 2009!
Just think how much money you could be making, writing articles and books in support of ID, and generally fleecing the credulous masses, if it weren’t for those pesky ethics.
When irreducible complexity is used to discredit evolution the assumption is made that evolution adds and takes away pieces. An evolving bike wouldn’t go from no wheel to wheel. A bike would more likely evolve from perhaps having a hexagonal wheel to a round wheel.
Bob:
Actually, if you go by what Behe wrote in Darwin’s Black Box, he makes the tacit assumption that evolution only adds, never removes. Otherwise, he might have recognized the scaffolding counterargument.
Ahaha, someone make it stop! There is no way, not even in principle, that it is possible to prove that there ISN’T irreducible complexity due to the same reason that you can’t prove that there ISN’T a God. That said, it makes both questions not even wrong.
I find it mind-boggling that creationists can claim the impossibility of disproving God somehow adds credibility to the God hypothesis, yet when they readily try to disprove the undisprovable with this IC nonsense – with the exact opposite result: “I can’t disprove evolution in this case, hence evolution never happened” – this opposed to “I can’t disprove God, hence God exists”.
Freidenker:
Actually, it is possible to define irreducible complexity in such a way that certain systems are demonstrably IC. For instance, as Behe does, define an IC system as one where you can’t remove a part without it ceasing to function (saying nothing about adding parts). Or by saying that a system is IC if, if you remove a part, it no longer serves its original function (saying nothing about the parts serving different functions).
The problem then, though, is that it doesn’t disprove evolution. If you allow adding parts, then that opens the possibility of a scaffolding. And if you only consider the original function of the system, then you ignore the fact that subassemblies may serve other functions that may have been selected for.