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The ID debate - "irreducible" design - Zarbi [entries|archive|friends|userinfo]
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The ID debate - "irreducible" design [May. 6th, 2008|03:22 am]
zarbi
I have heard "why can't science be open to teaching both sides of the argument for ID?" so often it has become wearing.

The response to this is that there aren't two sides involved, as one supposed side isn't science. Science involves the statement of hypotheses that can be explored and tested through experiment. How do we do this with supposed design? It just isn't possible. The statement that a biological feature appears designed is a declaration of belief, not an hypothesis. It is not testable.

However, a related statement - that a biological feature is too complex to have arisen without intervention by some intelligence - can be falsified, simply by the discovery of how such a feature actually did arise.

There are still problems even with this related statement. First, supporters of ID like the infamous Michael Behe seem not to want to take notice of evidence that falsifies a claim (such as how the supposedly "irreducibly complex" bacterial flagellum works with fewer components (and so is reducible), and is close in structure to a secretory system, so could clearly have evolved from it). Second, the claim that a structure is too complex to have arisen naturally is virtually impossible to prove. The number of evolutionary routes by which a structure could potentially arise are probably always very large indeed. Features can arise from simpler systems gaining complexity, or more complex systems becoming simpler, and this can involve systems which have quite different functions. An attempt to show that a structure had to have been designed has to involve eliminating the possibility of any evolutionary route to the structure. That is quite a challenge.

So, the idea of design by intelligence isn't scientific. There is no reasonable strategy for obtaining definitive evidence for design. The only reasonable approach for investigating complexity in biological systems is to search for evolutionary and/or physical explanations for that complexity. What the ID proponents have to explain is how they define the point at which we have completed all possible searches, assuming that this is even a meaningful question.
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Comments:
From: (Anonymous)
2008-05-06 04:04 pm (UTC)
If you say that ID is not science because can't be falsified because it can't be tested, and then you say that the ID claim that a biological feature is too complex to have arisen by Darwinian mechanisms has been falsified, you're undermining your claim that ID is not science because it can't be tested and falsified.

First, supporters of ID like the infamous Michael Behe seem not to want to take notice of evidence that falsifies a claim (such as how the supposedly "irreducibly complex" bacterial flagellum works with fewer components (and so is reducible), and is close in structure to a secretory system, so could clearly have evolved from it)

If you are tacitly admitting that the infamous Behe's claim of IC is falsifiable, then you can't at the same time say it's not science.

Second, as a empirical matter, to the best of my knowledge the function of propulsion via a rotary motor and a propeller in a bacterial flagellum has never been demonstrated to work with fewer components. Knock out experiments repeatedly produce the same results.

... is close in structure to a secretory system, so could clearly have evolved from it

The definition of IC has always referred to the function of the system as a whole, not to possible functions of it's individual components.

Saying that because a bacterial flagellum is close in structure to a secretory system, it could clearly have evolved from it, as if the mere logical possibility were tantamount to it actually having a homologous origin is a non sequiter which ignores the logical possibilities of convergence and coincidence, not to mention the logical possibility of common design. Such an extremely low threshold for scientific credulity, imho, evinces a presuppositional commitment to Darwinian mechanisms that is independent of, and not derived from scientific evidence, particulary with regard to the bacterial flagellum. A little healthy scientific skepticism is in order: Which came first, the secretory system, or the flagella?

Second, the claim that a structure is too complex to have arisen naturally is virtually impossible to prove. The number of evolutionary routes by which a structure could potentially arise are probably always very large indeed. Features can arise from simpler systems gaining complexity, or more complex systems becoming simpler, and this can involve systems which have quite different functions. An attempt to show that a structure had to have been designed has to involve eliminating the possibility of any evolutionary route to the structure. That is quite a challenge.

It sure is. Darwin knew the impossibility of proving a universal negative too, which is is why his subtle shifting of the burden of proof away from his own theory was so rhetorically clever: "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."

The irony in your post is that you set out to demonstrate the weakness of ID theory in its resistance to falsification and what you inadvertently end up showing is that in principle there is no experimental evidence that could possibly be found that would falsify the contention that complex molecular machines evolved by Darwinian mechanisms.

Cordially,

(Reply) (Thread)
[User Picture]From: zarbi
2008-05-06 04:20 pm (UTC)
I stated quite clearly that what could be falsified was a statement that a particular design was irreducible. What I stated was not falsifiable or testable was the involvement of a designer. Falsifiability is not the only criterion for a scientific statement. Hypotheses also have to be able to be demonstrated to be provisionally correct. This is not possible with the idea of design, or the idea of irreducible complexity.

I also stated that ID proponents would refuse to accept such evidence. Sadly, this seems to continue to be true.

It is not up to those with mainstream views to demonstrate that the bacterial flagellum definitely arose from a secretory system - the implication that this is at least possible refutes the argument from complexity. It is up to IDers to demonstrate that this could not have happened.

Demonstrations of the principles by which Natural Selection can give rise to complex systems have been observed. Entire novel metabolic pathways for the handling of man-made compounds have appeared in single-celled organisms on a timescale of only decades.

If you have any serious challenges to current theories of evolution, please present them in a formal manner and they can be reviewed when they appear in a respectable refereed journal. Such challenges have been proposed in the past, and published.

You reveal your ignorance of the current understanding of evolution. Some of Darwin's ideas have already been shown to be incorrect and incomplete. Examples are that we now know that evolution can occur through the transfer of information between different lineages by viruses and also through genetic drift rather than positive selection.

But, the question here is not the correctness or otherwise of Darwin's ideas. It is whether or not ID is science.

ID is not an attack on Darwinism. It is an attack on all of science.

It is up to you to propose experiments that can test for actual design, and not simply gaps in our knowledge. You also have to provide, as I describe above, a criterion for when we give up looking for alternative explanations and accept the work for your supposed designer.

Edited at 2008-05-06 05:35 pm (UTC)
(Reply) (Parent) (Thread)
From: (Anonymous)
2008-05-07 01:30 pm (UTC)
Steve: "I stated quite clearly that what could be falsified was a statement that a particular design was irreducible."

Well, yes, but... there's something fishy about the whole enterprise of "irreducible complexity." I think it's the argument from ignorance in disguise. It means the same as "how de hell did dat git liek dat??!!"

It's not a useful concept for a scientist.
(Reply) (Parent) (Thread)
From: (Anonymous)
2008-05-07 01:33 pm (UTC)
D'oh! Dr Benway here. I made the last post but forgot to say who I was.
(Reply) (Parent) (Thread)
[User Picture]From: zarbi
2008-05-07 01:37 pm (UTC)
No need. I recognised the titmouse by its roar.

Of course, you are right. There is a bad smell about the whole irreducible complexity idea. As I have said, I think it can be shown to be smelly in a way that should be clear to anyone by asking what the criteria is for giving up trying to explain biological feature. Do we say "OK, you have 20 years to explain that, or we'll go for the Designer option"? I guess the Michael Behe answer is we give up straight away. That stinks.

Edited at 2008-05-07 01:57 pm (UTC)
(Reply) (Parent) (Thread)
From: (Anonymous)
2008-05-07 02:24 pm (UTC)
I say more on my blog: "Is there an 'F' in Moron?" (http://tuftedtitmouse.blogspot.com/2008/05/is-there-f-in-moron.html)

If
each
reply
indents,
pretty
soon
things
will
get
skinny!

--Benway
(Reply) (Parent) (Thread)
[User Picture]From: zarbi
2008-05-07 02:35 pm (UTC)
I can probably turn off indenting. I am still learning how to play with styles on this site. (I quite like blogger, but I have been using this site for a very long time, and have friends here).
(Reply) (Parent) (Thread)
From: (Anonymous)
2008-05-08 04:42 am (UTC)

thanks much

well done, dude
(Reply) (Thread)