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Author
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Topic: Engineering & Darwinian Theory
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Evan
Member
Member # 164
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posted 09. April 2002 19:48
Here's how I understand Behe:
1) Behe defines IC to be a “a system performing a given basic function is irreducibly complex if it includes a set of well-matched, mutually interacting, nonarbitrarily individuated parts such that each part in the set is indispensiable to maintaining the system's basic, and therefore original, function.” (I am quoting Nelson Alonso here, but I am not sure if Nelson is quoting Behe verbatim.)
2) Behe also claims, as an hypothesis, that IC systems can not evolve in a step-wise fashion.
The definition (1) is just that - a definition that one can accept as useful, or not; but the second statement (2) is an empirical claim that can be investigated.
However, the two issues have to be kept separate: one has to look at a system irrespective of any knowledge as to how it came into existence and declare whether if fits the definition of IC; and then one can investigate whether it did in fact come into existence via evolutionary processes.
If one finds that what one declared as meeting the IC definition did in fact evolve, then that is evidence that the hypothesis (2) above is false.
What one can not do, in the face of evidence about the evolution of IC systems, is declare that, “Oh, then the system must not really be IC.” If one does that, one is certainly getting the cart and the horse backwards by treating the definition of IC (1) as an empirically investigateable hypothesis about origins and causation; and treating the empirical hypothesis about IC (2) as an assumed truth.
And here’s how I understand Dembski:
1) Dembski defines complexity as being that which has an improbable chance of coming into existence via law and chance (and he defines specified complexity as that which not only is improbable but also matches a specification.)
Notice the difference between Behe and Dembski: Behe defines something and then hypothesizes that nature could not produce something with those characteristics (i.e. ICness)
However, for Dembski, the claim that nature can not produce something (in this case, CSI) is embedded in his definition: it is not a separate statement as it is in Behe’s case.
Therefore, if we investigate something that Dembski would claim contains CSI and show that in fact it is probable that it evolved naturally, then we would conclude that it did not contain CSI.
So Behe’s and Dembski’s core arguments do not contain a parallel structure. If one were able to conclusively show that natural evolutionary processes could accomplish all we see in biology (a position that both Behe and Dembski deny, of course) we would be justified in concluding the following:
1) In respect to Behe, that IC structures can evolve, and
2) In respect to Dembski, that CSI does not exist.
Comments?
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Nelson Alonso
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Member # 52
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posted 09. April 2002 19:56
I agree with Dembski that specified complexity is something that natural processes cannot generate. This is, however, different from saying that specified complexity is something that the Darwinian mechanism cannot generate, which is what I referred as being "silly". In the broader view of chance + law this can be applied to things like the moon and the sun, and this also includes the Darwinian mechanism, and things like complexity theory, etc.
However, this does not translate into your points about IC, which is really the main thrust of my post. Nowhere in the ID literature can you find IC(A) where the definition contains the statement "it did not evolve". This is more of a consequence then a part of the definition. This is true even in ICfinal.
With respect to changing functions, what you are referring to is an indirect route, not a direct route, which the IC definition, as a consequence, rules out. Behe's definition does not rule out, a circutious route (as I showed with my a + b + c example). Furthmore, when one attempts to give a co-option argument against IC systems like the bacterial flagellum, the argument inevitably becomes what Orr calls "a miracle", where you would of course not expect your air conditioner suddenly working with your engine. see http://www.idthink.net/tel/flag5/index.php
With respect to Dembski's ICfinal, the basic function of the system like flagellum is scored as motility, then this is the function that definition refers to. To assume that there was another function that did not incorporate the parts is again, appealing to a circutious route which runs into the problems Mike Gene points to in his article above. To assume that there were various functional intermediates that were doing something else along each and every step is ultimately ad hoc, or even worse (for Darwinists), supports ID. Note that pointing to the impossibility of a direct route is not a strawman, co-option is actually quite non-Darwinian.
Note I'm going to be hopping over to ARN for the next few days since I haven't been there for a few days, so I my replies in this forum will be kind of slow.
[ 09 April 2002, 20:12: Message edited by: Nelson Alonso ]
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Evan
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Member # 164
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posted 09. April 2002 20:31
Nelson Alonso writes (but I am not sure whether in response to me or Drosera),
quote:
However, this does not translate into your points about IC, which is really the main thrust of my post. Nowhere in the ID literature can you find IC(A) where the definition contains the statement "it did not evolve". This is more of a consequence then a part of the definition.
(My emphasis.)
I think this last sentence exemplifies some confusion. If one considers that “non-evolvability” is a logical consequence of the definition of IC (which Nelson seems to imply), then Behe’s argument becomes like Dembski’s: evidence that something evolved merely shows that the structure in question is not IC (because if were IC, it couldn’t evolve.)
However, if one considers “non-evolvability” of IC structures as a “consequence” of the definition of IC in the sense of being a reasonable hypothesis that might be true, then it is an empirically investigateable statement separate from the definition, as I explained in the previous post.
It seems that it would be useful for this distinction to become clear one way or the other, but not to vacillate between these two possible understandings.
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Drosera
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Member # 139
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posted 09. April 2002 23:14
Hey there Nelson,
You wrote:
quote:
I agree with Dembski that specified complexity is something that natural processes cannot generate. This is, however, different from saying that specified complexity is something that the Darwinian mechanism cannot generate, which is what I referred as being "silly". In the broader view of chance + law this can be applied to things like the moon and the sun, and this also includes the Darwinian mechanism, and things like complexity theory, etc.
??? This appears to be the opposite of what you said in my original quote of you. But if you agree that specified complexity = (basically) "something natural processes cannot generate", then I guess my point has been made. Note then, that if you believe this then you can't go around saying, like you did before, that "The point however, is obvious. It is not a matter of whether specified complexity exists in nature, but if specified complexity can be generated by naturalistic processes." You appear to acknowledge this now so I'll drop it.
quote:
However, this does not translate into your points about IC, which is really the main thrust of my post. Nowhere in the ID literature can you find IC(A) where the definition contains the statement "it did not evolve". This is more of a consequence then a part of the definition. This is true even in ICfinal.
This is debatable at best. In actual practice, ID writers, when confronted with evidence that such-and-such a putatively IC system actually evolved, often say something along the lines of "if it evolved, then it's not IC". As I said before, the problem started with Behe's original definition:
quote:
By irreducibly complex I mean a single system 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. An irreducibly complex system cannot be produced directly (that is, by continuously improving the initial function, which continues to work by the same mechanism) by slight, successive modifications of a precursor system, because any precursor to an irreducibly complex system that is missing a part is by definition nonfunctional.
So, the question is, is the second sentence part of the definition, or not? Philosopher Todd Moody, an ID proponent (author of "Intelligent Design: A Catechism" Philosophy Now, (March/April, 2001), see here, wrote exactly what Nelson says shouldn't exist, in an article online, entitled "Three Levels of Design":
quote:
The reason for this, according to Behe, is that the system required for even the simplest life form are irreducibly complex, meaning that they cannot be gradually arrived at by means of a sequence of slightly less complex but nevertheless viable systems.
Here is another source of ID literature (intelligentdesign.org) saying something similar:
quote:
The answer is a simple one. Evolutionists know that if there is such a thing as an irreducibly complex system in the man-made world, then it is quite possible, that before too long, we may find a version of a similar system in the biological world. Upon close examination, the systems in the man-made world often parallel those of the biological world. Therefore, if we prove the existence of irreducible complexity in the man-made world, it won't be long before biologists begin to find similar examples of irreducible complexity in the biological world.
Any substantiation of irreducibly complex biological systems would put unbearable pressure on Darwinians, perhaps even driving the final nail through the coffin of Darwinian evolution.
(italics original)
...this kind of "If IC exists, then Darwinian evolution is sunk" logic relies on IC version A (IC=something that can't evolve, by definition). I recall Discovery Institute fellow Jeffrey Schloss saying basically this in a talk that I saw online, also (sorry, I can't find it at the moment).
And then, of course, there is Behe's new definition of IC, which is clearly another version of IC (a):
quote:
An irreducibly complex evolutionary pathway is one that contains one or more unselected steps (that is, one or more necessary-but-unselected mutations). The degree of irreducible complexity is the number of unselected steps in the pathway.
(In Defense of the Irreducibility of the Blood Clotting Cascade)
...in other words, if it has many unselected steps, the odds become vanishingly low that natural evolution can reach the system -- meaning, the lower the odds of natural evolution, the more IC it is.
And finally, Dembski himself said in the Introduction to No Free Lunch,
quote:
Irreducibly complex biological systems exhibit specified complexity. Irreducible complexity is therefore a special case of specified complexity.
...but how can IC be just a subset of SC, unless IC is also defined probablistically?
I will agree that IC version (b) is also used by ID authors, and is probably the what Behe actually means. I just want to point out the confusion among those who use the concept. It is confusing the two versions, (a) and (b), and switching back-and-forth, that makes things fishy.
If we all agree that version (b) is the right one, then that's fine and we can argue about what, if anything, version (b) implies about the capabilities of natural evolutionary processes. My opinion, as I said before, is not much, primarily because of common changes of function in evolution.
Moving on to this:
quote:
With respect to changing functions, what you are referring to is an indirect route, not a direct route, which the IC definition, as a consequence, rules out. Behe's definition does not rule out, a circutious route (as I showed with my a + b + c example).
So what's the point of IC then? Changes in function are very commonly in evolution, and have been important in explaining the origin or complex systems since the time of Darwin himself. Are you admitting that the IC argument doesn't prove anything about evolution, because the IC argument is ignoring a very important part of it? ![[Smile]](smile.gif)
quote:
Furthmore, when one attempts to give a co-option argument against IC systems like the bacterial flagellum, the argument inevitably becomes what Orr calls "a miracle", where you would of course not expect your air conditioner suddenly working with your engine. see http://www.idthink.net/tel/flag5/index.php
Dembski plays the Orr card also in No Free Lunch, but this argument is not convincing. Even if Orr is saying what Dembski, Nelson, etc. want Orr to be saying, he is but one authority among many. And anyhow, I don't even think Orr is saying what ID advocates want him to be saying.
Here is the Orr quote that Nelson and Dembski rely on to dodge the change-of-function argument:
quote:
"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."
The crucial sentences here are the bolded ones. But what, exactly, does he mean? Here is a classification (mine, I just came up with it) of change-of-function. My general assessment of their probability is included.
quote:
1a) System with new function forms when all of the parts come together at once from proteins with different sub-functions. Drastically unlikely.
1b) System with new function forms when all of the parts come together at once from proteins with *similar* sub-functions. Still drastically unlikely, although not as much as #1.
Orr, Nelson, and Dembski all agree that #1 is unworkable. This is a straw-man of a real cooption argument however, so if this is what you think of when "change of function" comes up, then you are thinking of a straw-man of the actual cooption argument.
2a) System with new function forms by co-optation of a pre-existing multipart system with a wildly different function (Orr's transmission-airbag example).
[My problem with Orr here is that he is too brief and is therefore unclear: "different function" can mean many different things. E.g., do pili and flagella have "wildly different
functions" or not? They are certainly different, but they are closely related in many ways (both required the export of filament proteins, regulation of length, etc.).]
If my characterization of Orr is correct here, I would agree that 2a would be unlikely: "Such things might happen very, very rarely, but they surely do not offer a general solution to irreducible complexity."
2b) System with new function forms by co-optation of a pre-existing multipart system with a somewhat different function (e.g. car-doors-become-airplane-wings would be a mechanical analogy similar to legs-become-wings or pili-becomes-flagellum. This is what I mean by "related", which shows what a difficult concept it is when one uses mechanical analogies rather than the more appropriate biological ones. Legs-into-wings is rather like car-doors-into-airplane-wings). This is IMO mildly common, especially for the origins of the
most complex systems.
3) System with new function forms by taking an old system with a "related" function and adding:
a1) a group of parts with an unrelated subfunction
a2) a part with an unrelated subfunction
b1) a group of parts with a related subfunction
b2) a part with a related subfunction
I would regard (a1) as mildly likely, (a2) and (b1) as somewhat likely, and b2 as downright common.
4) Orr's "a part is first helpful, then becomes necessary". This is certainly ubiquitous. Behe has however recently tried to exclude this case from being IC at all (whether or not we want to allow Behe to make this move is another question altogether) -- see his Biology and Philosophy article here.
Cooption version #1 corresponds to Orr's first 3 sentences, and Orr rules these out, correctly in my opinion
Scenario #2a is what he thinks "might happen very, very rarely, but they surely do not offer a general solution to irreducible complexity", and if I'm reading Orr correctly, then I would agree with him here.
This however leaves 2b, 3, and 4 as wide-open possibilities that I doubt very much that Orr would consider unlikely. All of this goes to show that relying on one simplistic interpretation of exactly two sentences of Orr is a very thin basis on which to dismiss the change-of-function argument.
quote:
With respect to Dembski's ICfinal, the basic function of the system like flagellum is scored as motility, then this is the function that definition refers to. To assume that there was another function that did not incorporate the parts is again, appealing to a circutious route which runs into the problems Mike Gene points to in his article above.
I gather from lurking on www.arn.org that Mike Gene's article series is still incomplete -- I have read them after seeing them referenced on ARN, but certain key issues remain for him to address, so it will be hard to comment until the series is complete. I have mentioned numerous additional evidence for the evolution of 'IC' systems in other threads on ISCID (here).
quote:
To assume that there were various functional intermediates that were doing something else along each and every step is ultimately ad hoc, or even worse (for Darwinists), supports ID. Note that pointing to the impossibility of a direct route is not a strawman, co-option is actually quite non-Darwinian.
Huh? What are you talking about? Let's consult Darwin on what's Darwinian, shall we?
(from Origin of Species)
quote:
Chapter 6
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. No doubt many organs exist of which we do not know the transitional grades, more especially if we look to much-isolated species, round which, according to my theory, there has been much extinction. Or again, if we look to an organ common to all the members of a large class, for in this latter case the organ must have been first formed at an extremely remote period, since which all the many members of the class have been developed; and in order to discover the early transitional grades through which the organ has passed, we should have to look to very ancient ancestral forms, long since become extinct.
We should be extremely cautious in concluding that an organ could not have been formed by transitional gradations of some kind. Numerous cases could be given amongst the lower animals of the same organ performing at the same time wholly distinct functions; thus the alimentary canal respires, digests, and excretes in the larva of the dragon-fly and in the fish Cobites. In the Hydra, the animal may be turned inside out, and the exterior surface will then digest and the stomach respire. In such cases natural selection might easily specialise, if any advantage were thus gained, a part or organ, which had performed two functions, for one function alone, and thus wholly change its nature by insensible steps. Two distinct organs sometimes perform simultaneously the same function in the same individual; to give one instance, there are fish with gills or branchiae that breathe the air dissolved in the water, at the same time that they breathe free air in their swimbladders, this latter organ having a ductus pneumaticus for its supply, and being divided by highly vascular partitions. In these cases, one of the two organs might with ease be modified and perfected so as to perform all the work by itself, being aided during the process of modification by the other organ; and then this other organ might be modified for some other and quite distinct purpose, or be quite obliterated.
The illustration of the swimbladder in fishes is a good one, because it shows us clearly the highly important fact that an organ originally constructed for one purpose, namely flotation, may be converted into one for a wholly different purpose, namely respiration.
...
In considering transitions of organs, it is so important to bear in mind the probability of conversion from one function to another, that I will give one more instance. Pedunculated cirripedes have two minute folds of skin, called by me the ovigerous frena, which serve, through the means of a sticky secretion, to retain the eggs until they are hatched within the sack. These cirripedes have no branchiae, the whole surface of the body and sack, including the small frena, serving for respiration. The Balanidae or sessile cirripedes, on the other hand, have no ovigerous frena, the eggs lying loose at the bottom of the sack, in the well-enclosed shell; but they have large folded branchiae. Now I think no one will dispute that the ovigerous frena in the one family are strictly homologous with the branchiae of the other family; indeed, they graduate into each other. Therefore I do not doubt that little folds of skin, which originally served as ovigerous frena, but which, likewise, very slightly aided the act of respiration, have been gradually converted by natural selection into branchiae, simply through an increase in their size and the obliteration of their adhesive glands. If all pedunculated cirripedes had become extinct, and they have already suffered far more extinction than have sessile cirripedes, who would ever have imagined that the branchiae in this latter family had originally existed as organs for preventing the ova from being washed out of the sack?
Notice that, not only are changes of function explicitly discussed, in several places. by Darwin himself, in the very heart of the Origin of Species, (leaving aside the question of whether he got particular transitions right, e.g. air-bladder-->lungs or 'lungs'-->air bladder?), but he discusses, and explicitly emphasizes the point, in the very section that Behe built his IC argument to critique! I'll quote it again, just in case anyone skipped the above longer quote (sorry):
quote:
In considering transitions of organs, it is so important to bear in mind the probability of conversion from one function to another, that I will give one more instance.
(emphasis added)
How then can Nelson (let alone Dembski, Behe, etc.) justify giving change-of-function such short shrift in their arguments? It is the key item to consider, not some obscure sideshow. Yet Behe gives it less than a paragraph of discussion in Darwin's Black Box, Dembski tries to define it out of existence in his new definition 'ICfinal', and Dembski and Nelson both rely on a debatable interpretation of a mere two sentences of one ID critic (Orr) in an attempt to exclude change-of-function from the debate.
Thanks for the discussion, Nelson, I find this kind of clarification-of-terms discussion one of the most useful parts of online discussions, things don't go anywhere when people are talking past each other.
Drosera
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edmund
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posted 09. April 2002 23:47
As a general observation, I've noticed (here and elsewhere) that a lot of confusion can be generated by semantics and unnecessary logical arguments. To avoid this, I think a good rule of thumb would be to stay as close as possible, in one's arguments, to thinking about what actually happens :
Instead of "can irreducibly complex systems evolve?", why not "can systems with multiple interacting parts evolve"? That avoids confusion over what IC is, and is perfectly adequate for most discussions.
Also, this thread seemed to start with a discussion of whether "engineering language" used by biologists implies that design is an empirical fact. It is not clear to me that the language used by anyone affects the historical facts which led to present-day organisms. We get distracted pretty easily. Many discussions get lost in murky side alleys; IMO, we would accomplish more if we stick close to the clear highway: "What actually happened?" and "How do we know that?"
This isn't a criticism of anybody or any idea in particular-- just a general suggestion.
--edmund
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Dennis L. Feucht
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posted 10. April 2002 00:24
James Barham,
"Any analogy between nature and engineers assumes ID."
I simply meant that engineers are IDers and the analogy attributes ID to nature.
edmund,
re: "essentially no different"
I meant that to the extent that artifacts and organisms share similar characteristics, then I see not reason why this would not also apply to the IC characteristics of both of them
Regarding the analogy and the speed-torque trade-off - this is a behavioral description, not a functional description because no goal as such is involved. It is simply a physical constraint relating torque and speed. So I would agree that teleology is not involved in behavioral descriptions. But it necessarily is in functional descriptions.
By "function" I refer to the achievement of goals by a system. This is the common use in the artifical intelligence (AI) literature. (For a fuller explanation of functional versus behavioral descriptions, see my article, "Design in Nature and the Nature of Design" on the www.arn.org website.)
Drosera,
Your IC definitional distinction is quite helpful; I have been applying a meaning to "IC" following Behe's lead, meaning a system reduced to its essential components, such that if any component is removed none of the resulting possible behaviors achieves the goal of the original system. This is along the line of your definition (b).
Behe then makes the argument that various features of organisms are IC through the inference (which is the main point of controversy) that incrementally-constructed systems cannot be IC.
I accept the definition of IC given by Behe and your (b). But I do not know whether certain kinds of systems (such as TVs or computers) can be built up incrementally or not. My experience from engineering is that some systems cannot - or at least, nobody has found a way to do so. In other words, I suspect that some IC artifacts are not able to be constructed through successive designs that differ only incrementally. The main reason for this is simply due to the highly nonlinear nature of systems that appear to disallow it.
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Nelson Alonso
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posted 10. April 2002 11:50
To Drosera:
I don't know if you frequent ARN much but I'm going to be starting a thread over there (after replying to various other threads) that contains a full reply to your response. Your post is simply a rehash of some pretty basic anti-ID arguments and does not belong in this thread (and most likely does not belong on this board). This thread is mostly comparing complex biological systems to human made complex systems, and how a direct route does not work for either, if you have a problem with this subject, then by all means continue posting on this. But I don't want to get zapped by the moderator by posting a point by point reply. Note I take partial blame for hijacking the thread.
To Evan:
A thorough discussion about the definition of IC compared to SP does, and the consequences of these definitions, in my opinion, belong in this forum (the moderator could disagree). However, it is still irrelevant to this thread. I would suggest starting a new thread and you and I can focus on this topic. Note if by the time I get back here I don't see a thread on this subject, I'll start one myself and address the issues you brought up here. But I don't feel right starting the thread, and if it ends being a really good thread and wins thread of the month, I wouldn't feel right accepting the prize, since it's really you who brought up the issue (although I could use the cash! ![[Wink]](wink.gif) ).
[ 10 April 2002, 13:41: Message edited by: Nelson Alonso ]
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Janitor@MIT
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posted 10. April 2002 13:09
I think Dennis L. Feucht is well warranted in wondering about some sort of “vitalism” at work in modern evolutionary thought. Biology has a long history of conflict with physicists—but since the Biological Revolution the physicists seem to be preoccupied with their own problems. Maybe its time that engineers took a more active interest in the use and abuse of engineering design theory and experimental results (results which aren’t so much abused as simply ignored) by biological theorists.
The implicit argument appears to be that life is amenable to (superficial) engineering analysis but somehow violates the physical constraints on optimization, the limits of computation, and adapts dynamically in ways that no one understands. Vitalism?! The irony is that traditionalists pose their theory as a “mechanical” alternative to anachronistic vitalisms. But I fail to see the distinction. This is a “metaphysical” theory in a larger sense than Popper meant. It appeals directly to non-physical processes (explicitly where historical narratives are substituted for scientific explanations), posits effects as causes (natural selection), and as causes effects that are utterly incompetent and inconsequential (random mutation). The ghost in the machine is Darwin’s.
Bravo to Dennis L. Feucht! Trust your engineering intuitions. This is a theory that cannot be reconciled with 150 years of experimental results in engineering.
P.S., As near as I can tell, Behe’s definition of “IC” corresponds with standard definitions of “function,” “machine,” and “system” found in engineering theory. It wasn’t engineers who discovered biological “functions” and biological “machines,” it was the biologists. The biologists have insisted that these functions and machines evolve in ways that are “bizarre” to say the least, from an engineering perspective. If the biologists cannot reconcile their theory with the physics (engineering) then Dennis L. Feucht should trust his impression about “vitalism.”
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Moderator
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posted 10. April 2002 15:48
This is a general warning to all those participating in this thread. Please stay on topic. You are allowed at maximum two posts to "clarify" side issues. However, you are not permitted to completely re-direct the focus of the thread.
I would appreciate a renewed focus on Dennis' initial post.
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Moderator
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posted 10. April 2002 15:55
This is a specific warning to Drosera. We frown upon point-by-point rebuttals. I've noticed this tendency of yours in several instances. Please refrain from this practice and give us some posts that contain more of your own thoughts than somebody else's quotes.
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James A. Barham
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posted 10. April 2002 18:14
Dennis:
You wrote:
"I meant that to the extent that artifacts and organisms share similar characteristics, then I
see not reason why this would not also apply to the IC characteristics of both of them"
But the question is, What are the relevant similarities? I agree completely with your simple definition of "function" as goal-seeking, and I also agree that both engineered artifacts and organismal processes and behaviors are functional in this sense. But does this mean that they are necessarily the same in all respects? I don't see why it should.
The way I look at it, engineering ideas are helpful in elucidating biological functions because the organism is marshalling efficient causal processes for final ends. But this marshalling itself cannot be understood in purely engineering terms, because it is analogous to the intelligence with which we deploy efficient causality for our own ends, and our own intelligence is not susceptible to an engineering analysis, at least not completely.
In short, some similarities between engineered artifacts and organic structures and processes do not prove identity. A good example is the heart/pump analogy. Sure, it is possible to throw a lot of light on the circulatory system by using the analogy to human pumps and plumbing. But the usefulness is limited. Keep in mind the differences, as well. If an organic heart is disaggregated into its individual cells, and the cells placed in a suitable medium, then the myocardial cells will crawl back together and form a large mass that will begin pulsing rhythmically on its own---clearly trying to reconstitute itself as a working heart. If you smash an artificial heart to bits, the pieces of dacron and titanium (or whatever) sure as heck won't do that!
Janitor:
I think you are right about the crypto-vitalism underlying Darwinism. You might say that my whole project is to make Darwinism come clean on this point!
However, I would point out that this vitalism is not necessarily so disreputable from the point of view of physics. There is physics and physics. Your identification of physics with engineering overlooks the whole field of condensed matter physics and the growing efforts to understand the physics underlying protein function. This is a very far cry indeed from engineering. See Robert B. Laughlin et al., "The Middle Way," PNAS, 2000, 97: 32--37, among many other sources I could point you to.
[ 10 April 2002, 18:19: Message edited by: James A. Barham ]
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Drosera
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posted 10. April 2002 20:12
Hi,
Warning acknowledged. I've said my piece in this thread, apologies if it got off-topic, it would probably have been better to start a new thread. Definitions issues in particular get my gumption up.
Apologies on point-by-point rebuttals and long quotes, that is probably my lazy way of trying to be thorough. The internet makes it easier to quote people, rather than trying to sum up what they're saying...I'll be less lazy in the future. Unfortunately, though, in a few cases (e.g. addressing what is & isn't actually in the ID lit.) there really is no alternative to quoting someone.
Re-reading the original post by Dennis at the top of thread, though, it does seem that my comments regarding definitions and implications of IC are indeed pertinent:
quote:
In other words, Kenneth Miller's counter-argument against the IC of mousetraps is too simple. A compelling denial of the IC of a computer or television would be better. And if the IC of something so (relatively) simple as a TV cannot be denied, then how much more so for life.
...Dennis appears to be working under IC version A, rather than the apparently more-agreed-upon IC version B.
But, as I mentioned I've probably harped on this enough here.
Drosera
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edmund
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Member # 206
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posted 11. April 2002 02:08
"Regarding the analogy and the speed-torque trade-off - this is a behavioral description, not a functional description because no goal as such is involved. It is simply a physical constraint relating torque and speed. So I would agree that teleology is not involved in behavioral descriptions. But it necessarily is in functional descriptions.
By "function" I refer to the achievement of goals by a system. This is the common use in the artifical intelligence (AI) literature. (For a fuller explanation of functional versus behavioral descriptions, see my article, "Design in Nature and the Nature of Design" on the www.arn.org website.) "
Thank you for clarifying the distinction between "behavior" and "function" for me. In lght of this distinction, I will reformulate what I was trying to get at above:
Evolutionists would argue that biological systems "behave" rather than "function". It seems reasonable to me that a particular molecular structure might behave in such a way (i.e. interact with its environment in such a way) that there would soon be two such structures instead of one. Natural laws and the composition of the environment dictate that structures with certain behaviors tend to increase in number while structures with other behaviors decrease in number-- not because of a vital tendency or anything unmeasurable, but simply because physical laws cause certain behaviors to lead to their own increase or decrease.
This process will lead very rapidly to a group of structures with behaviors which are probabilistically unlikely based on chance alone. This process can be entirely deterministic, with no intentionality involved.* Nothing within the physical universe I am describing has a "goal", and there is no interruption of natural law in any way. The behaviors which natural laws cause to increase in number are those which we see in biological organisms: behaviors which act on the environment in some way such that more such behaviors get produced.
In other words, there exists a logically consistent scenario in which systems with the behaviors that we see in living organisms are generated by natural laws without any intrinsic teleology. Your initial post seemed to insist that this was not possible. (If I have misunderstood your initial argument, please correct me!)
*Actually, there can be teleology involved, in certain ways. The behaviors are increasing or decreasing in frequency in response to 1) the structure of the logical and physical laws of their universe, and 2) chance, whatever that is. If these have teleology behind them, then the changes in the behaviors occur with a certain goal "in mind". I.e., an intelligent designer might be shaping the final outcome, but without actually being detectable within the system.
--edmund
A few side notes, which perhaps stray from topic but which might be useful for future discussion:
1. Is there any objective way to tell a behavior from a function? I understand that we can do this with human artefacts because of our prior knowledge about the teleology behind their manufacture-- we know all about humans and the functions they require from their tools. But without this prior knowledge, is there any ironclad way to distinguish behavior from function just by observation of the system in question?
2. One of the real headaches of ID is: what *is* the function of biological organisms? If it is reasonable to say that organisms are artefacts because they are complex like artefacts, then it follows unavoidably that-- like artefacts-- they have a purpose. One of the stumbling blocks to Paley's watchmaker thesis, when it was first made, was that nobody could come up with a convincing *goal* behind the apparent teleology of organisms. In my mind, articulating a clear, convincing "goal" would strengthen ID theory enormously.
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James A. Barham
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Member # 50
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posted 11. April 2002 14:56
I wonder whether we shouldn't be more careful about stipulating non-standard definitions of words. It seems to me that we are running the risk of a lot of confusion by doing so.
In standard usage, in both the biology and philosophy communities, only living things and objects designed by living things have "functions." It is true that "function" is sometimes used in other ways (like in mathematics), but in the literature on the philosophy of biology and the philosophy of mind, it is standard to restrict "function" to living things and their artifacts.
"Behavior" is problematic to use as a technical term equivalent to function, because its colloquial use referring to any change whatsoever is so entrenched in the physics community---e.g., "how a pendulum behaves in a gravitational field," etc. Therefore, we had better reserve "behavior" for the distinction between internal physiology and whole-organism locomotion, if we must use the term at all.
So, to sum up, inorganic systems undergo change in accordance with mechanistic and statistical laws, so as to minimize the energy under a given set of constraints, but only living things contain processes with true goal-directed functions, both instrumental and categorical---by which I mean, to keep the organism in existence.
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Dennis L. Feucht
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Member # 231
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posted 12. April 2002 20:33
James Barham,
"But this marshalling itself cannot be understood in purely engineering terms, because it is analogous to the intelligence with which we deploy efficient causality for our own ends, and our own intelligence is not susceptible to an engineering analysis, at least not completely."
The issue of the design of the human mind is a possible, notable exception. All other designed entities, however, give evidence of an intelligent designer though they are not intelligent in themselves.
Since engineering has not progressed to the point of being able to produce many of the functional capabilities of organisms, the better design of the heart emphasizes the existence of undiscovered latent principles of design inherent in it. Engineers have learned some design techniques by studying organisms, and the fact that this even happens reinforces (though does not prove) the notion that organisms are designed.
That is, if engineers do design, and what they do progresses by discoveries in organisms, then this suggests that organisms are designed. This works with little else than life itself. Studying rocks can lead to a better understanding of physical causes, but rocks achieve no significant function I am aware of. Another possible exception is the ecosphere, and the fine-tuned aspects of the solar system. But organisms really stand out.
Drosera,
I'm assuming IC version (b), but the mousetrap example may be too simple. My comment about Miller's refutation applies equally to Behe's use of this example. Behe does so to merely illustrate the idea of IC in talks, but a substantive refutation (by Miller) would, I expect, require at least a more complicated example of IC such as a TV.
edmund,
"... there exists a logically consistent scenario in which systems with the behaviors that we see in living organisms are generated by natural laws without any intrinsic teleology."
One of the issues of ID as applied to life is: at what conceptual level one should look for functional principles at work? Your point about population dynamics suggests additional constraints beyond those of the organism itself, applied (perhaps mostly) by the environment.
Physical constraints limit the range of possible behaviors, and if too limited, very little can be accomplished, and function is trivial (such as for rocks). But organisms have an ample complexity for many possible functional theories that have yet to be significantly explored. Geneticists are among those in the forefront of this exploration, given the huge number of possibilities allowed by DNA base-pair sequencing. Perhaps software engineers will pick up new techniques from geneticists of the future!
"Is there any objective way to tell a behavior from a function?"
Yes. Functions consist in patterns of behaviors and are the patterns and not the behaviors themselves. (See the section of my paper at www.arn.org titled "High-Level Behavioral Versus Functional Descriptions" for more.) Functions are NOT behaviors for which some purpose has been identified; they are the purpose itself.
"One of the real headaches of ID is: what *is* the function of biological organisms?"
This is very relevant to the issue! But it is probably not intractable. Just as devices can be reverse engineered by those who do not know the designer (e.g., the stereotypical Japanese reverse engineering of American integrated circuits in the '80s!), functions can be identified in organisms. What is more complicated is the identification of the organization of these functions into a conceptual hierarchy. But low-level functions are easily identifiable. The liver filters blood, the heart pumps it, etc. Medical diagnosis is the inference of faulty structure from faulty function.
Teleology - determining ultimate purposes, the highest-level functions - is indeed challenging. I don't think biology has progressed sufficiently to tackle it yet in earnest.
[ 12 April 2002, 20:41: Message edited by: Dennis L. Feucht ]
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