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Author Topic:   Irreducible Complexity (Slevesque & Dr Adequate Only)
Dr Adequate
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Posts: 15960
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(1)
Message 1 of 17 (609048)
03-16-2011 6:59 AM


Behe defined an irreducibly complex biological system as a system which is "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".

Creationists, following Behe's lead, often claim that irreducibly complex structures cannot evolve (to be more precise, cannot evolve by the processes detailed in the theory of evolution).

The argument is that an irreducibly complex system of n parts can't have evolved because natural selection would not have favored the evolution of the first n-1 parts of the system, because the first n-1 parts of the system would have conferred no selective advantage to the organism until the nth part was added to the system.

(I believe that I have stated the creationist position fairly: it is no desire of mine to argue against a straw man, and if any creationist would like to refine this argument by quoting from Behe, I should welcome the intervention.)

* * *

These claims about irreducible complexity have, in my opinion, often been misapplied, in that some creationists have held up as examples of irreducibly complex systems things which are, by Behe's definition, not actually irreducibly complex.

Let us leave this aside. An argument is not, after all, falsified by its misapplications. Let us instead take a look at some examples of things that actually are irreducibly complex.

* * *

My favorite example is the bones of the mammalian middle ear. There are three of them, the malleus, the incus, and the stapes, and vibrations are transmitted from on to the other, rather like the toy known as "Newton's Cradle". Take one away, and the whole assembly wouldn't work --- in fact, the whole darn ear wouldn't work. Since the removal of one part would remove the function, this is an irreducibly complex system.

And yet we can see in the fossil record how this evolved. (Or, if you are a die-hard creationist, at least admit that we can see in the fossil record how this could have evolved.) We have the intermediate forms (or, if you are a creationists, the things that look exactly like intermediate forms) showing how the incus and malleus took on their present form and position and role by gradual adaptations of form and position and function from the quadrate and articular bones of the reptilian jaw.

Just to be clear, if you're a creationist, you don't have to concede that this is how the mammalian middle ear evolved. It is, but let's save that argument for a rainy day.

No, my point is that the evolutionary explanation for the middle ear involves gradual shifts of form and position and function. Behe's argument fails because we don't need to imagine an evolutionary process in which (for example) the malleus and the stapes came first, and then the incus poofed into existence to fill the gap between them.

The sequence in the fossil record shows that we don't have to envisage a scenario where two of the three parts acquired their modern form and position first and then the third was tacked on. And even if you are a die-hard creationist and don't think that the fossil record is evidence of anything, nonetheless you must concede that we can see how the irreducibly complex system might have been produced by ordinary evolutionary modifications, and without two of the parts evolving and then the third being added.

* * *

Let's take another example. Mammals have two jaws to grasp and chew their food with: an upper and a lower jaw. Remove one of these parts, and all function is lost --- one jaw is about as much use for chewing as one millstone is for grinding. This structure is therefore irreducibly complex.

So, what can we conclude? Clearly, this: that the evolution of this system can't have occurred by one jaw developing first and then the second one being added to make the complete system.

And guess what? No biologist anywhere ever has claimed that this happened. Instead, they trace the evolution of jaws from pharyngeal arches ("gill arches") which already had a lower and upper half before they functioned as jaws. Fossils of interest include the early chordates Yunnanozoon and Haikouella, which have no jaws but which possess pharyngeal teeth.

(Some modern fish also have pharyngeal teeth on the pharyngeal arches behind their jaws. Here's a picture of pharyngeal teeth in modern carp.

In cichlids, the lower left and right first pharyngeal arches have fused together to form a lower "pharyngeal jaw" behind the true jaw.)

Now, whether or not you accept the evolutionary explanation for this irreducibly complex structure, it's plain that the fact that it is irreducibly complex does nothing to argue against the evolutionary explanation, since the explanation does not involve the system evolving one jaw at a time, nor yet two fully-formed jaws simultaneously appearing at a single stroke, but rather the gradual processes of adaptation of form and function that one associates with the theory of evolution --- that is, with the actual theory of evolution, the one in biology textbooks, rather than the imaginary theory of evolution that must have been rattling around in Behe's head when he came up with this stuff about irreducible complexity.

* * *

As a final example, divide yourself (conceptually) into two parts --- your head and everything else. A series of experiments conducted by the French researcher Dr Joseph-Ignace Guillotin have proved conclusively that one is useless without the other. You yourself are an irreducibly complex system.

And this would be a strong objection to any evolutionary scenario involving a bunch of human heads rolling about without bodies for a few millenia; or, alternatively, a bunch of headless people strolling around and bumping into things.

But this is not the scenario that biologists have put forward. Instead, they suggest that the process involved gradual encephalization starting with a segmented ancestor whose frontmost segments played no special role.

Again, you can believe that or not; but it is no objection to this theory to point out that today the human head+body that represents one of the end points of that process forms an irreducibly complex system. It is only an objection to a hypothesis in which heads magically appeared on human bodies which previously had lacked them, or vice versa --- a hypothesis to which no-one at all subscribes.

* * *

To summarize:

The fact that a system is irreducibly complex in no way suggests that it could not have evolved. It does, however, suggest that such a system cannot have evolved by a process in which the last step was the sudden wholesale addition of a part to a system which was otherwise identical to the system in question.

Which is why no biologist has ever attempted to explain any such system in any such way.

Now if Behe wants to argue against evolution, he should try arguing against the actual processes that are supposed to underlie evolution: the gradual modifications of form and function which biologists claim have occurred. Instead, he has an excellent argument against parts suddenly poofing into existence out of nothing to fulfill a role in a system which wouldn't work without them.

He is right to suggest that this does not happen. I suppose that pretty much every evolutionist from Darwin on would heartily concur. Hurrah, Behe has discovered one of the more obvious consequences of the theory of evolution! But he also has mistaken it for an argument against that same theory; and it is hard to see why he has made such an atrocious blunder except under the hypothesis that he's some kind of bloody fool.

* * *

To the moderators: slevesque indicated that he would be interested in having a one-on-one debate on this subject with some evolutionist in the Great Debate forum.

I immediately PM'd him and took him up on this.

For some reason he didn't answer. One can only speculate as to why. My own favored hypothesis is that he realized that I am such a delicate and sensitive soul that debating with me would be like trampling on a fragile little flower.

There might be another reason.

Anyway, my suggestion is that you should put this in whatever forum you see fit and open it up to general comments; and if slevesque decides that he wants to make it a Great Debate topic between the two of us, then I'd be happy to continue it there.

Edited by Dr Adequate, : No reason given.

Edited by Admin, : Modify title include list of sole participants.

Edited by Dr Adequate, : Removed ambiguity concerning the word "body"


Replies to this message:
 Message 2 by AdminSlev, posted 03-16-2011 8:47 AM Dr Adequate has responded
 Message 5 by slevesque, posted 03-18-2011 5:05 PM Dr Adequate has responded

  
AdminSlev
Member (Idle past 2196 days)
Posts: 113
Joined: 03-28-2010


Message 2 of 17 (609049)
03-16-2011 8:47 AM
Reply to: Message 1 by Dr Adequate
03-16-2011 6:59 AM


I would be happy to take on this discussion with you in the Great Debate section.

I'm sorry I didn't answer your PM, in retrospect I should have maybe given my intentions, which were simply to wait to see if someone who had participated actively in the discussion of IC in the other thread would want to do this, as I would have given them priority over you who made little contribution. (Don't take this personnally, it seemed like simply the right thing to do. Be assured I am very happy that you proposed yourself).

And so between preparing an opening post and studying for my quiz of today, I told myself I would just wait a day or two to see if either you would make an OP, or if I would receive another PM.

So in the meantime I won't promote this topic myself, and instead leave that to another admin because in any case even if I did do it now I wouldn't get a written answer posted before tonight.

I'll end by saying that hopefully the peanut gallery gets going, but I won't be answering directly there so if you see something worthwhile mentioned over there you'll simply have to be the one to bring it into the discussion here. Idem for me if any other points by creationists I think merits attention.


This message is a reply to:
 Message 1 by Dr Adequate, posted 03-16-2011 6:59 AM Dr Adequate has responded

Replies to this message:
 Message 4 by Dr Adequate, posted 03-16-2011 9:37 AM AdminSlev has not yet responded

  
Admin
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Message 3 of 17 (609051)
03-16-2011 8:55 AM


Thread Copied from Proposed New Topics Forum
Thread copied here from the Irreducible Complexity (For Slevesque) thread in the Proposed New Topics forum.
    
Dr Adequate
Member
Posts: 15960
Joined: 07-20-2006
Member Rating: 5.7


Message 4 of 17 (609054)
03-16-2011 9:37 AM
Reply to: Message 2 by AdminSlev
03-16-2011 8:47 AM


I'm sorry I didn't answer your PM, in retrospect I should have maybe given my intentions, which were simply to wait to see if someone who had participated actively in the discussion of IC in the other thread would want to do this, as I would have given them priority over you who made little contribution.

I've only made one answer to you about IC, but that's because you only made one post about IC. And then the moderators closed the thread just as it was getting interesting.

I'll end by saying that hopefully the peanut gallery gets going, but I won't be answering directly there so if you see something worthwhile mentioned over there you'll simply have to be the one to bring it into the discussion here. Idem for me if any other points by creationists I think merits attention.

Sure. If any creationist has any good point, bring it on. Also, if you can get Behe himself to join in, then that would be wonderful. The one thing missing from the Dover Panda Trial was that I didn't get to humiliate him myself, personally.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 2 by AdminSlev, posted 03-16-2011 8:47 AM AdminSlev has not yet responded

  
slevesque
Member (Idle past 2196 days)
Posts: 1456
Joined: 05-14-2009


(1)
Message 5 of 17 (609374)
03-18-2011 5:05 PM
Reply to: Message 1 by Dr Adequate
03-16-2011 6:59 AM


Behe defined an irreducibly complex biological system as a system which is "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".
Creationists, following Behe's lead, often claim that irreducibly complex structures cannot evolve (to be more precise, cannot evolve by the processes detailed in the theory of evolution).

The argument is that an irreducibly complex system of n parts can't have evolved because natural selection would not have favored the evolution of the first n-1 parts of the system, because the first n-1 parts of the system would have conferred no selective advantage to the organism until the nth part was added to the system.

(I believe that I have stated the creationist position fairly: it is no desire of mine to argue against a straw man, and if any creationist would like to refine this argument by quoting from Behe, I should welcome the intervention.)

I made the argument from parts being steps, and in biological systems, the basic unit for steps are mutations.


And yet we can see in the fossil record how this evolved. (Or, if you are a die-hard creationist, at least admit that we can see in the fossil record how this could have evolved.) We have the intermediate forms (or, if you are a creationists, the things that look exactly like intermediate forms) showing how the incus and malleus took on their present form and position and role by gradual adaptations of form and position and function from the quadrate and articular bones of the reptilian jaw.

Just to be clear, if you're a creationist, you don't have to concede that this is how the mammalian middle ear evolved. It is, but let's save that argument for a rainy day.

No, my point is that the evolutionary explanation for the middle ear involves gradual shifts of form and position and function. Behe's argument fails because we don't need to imagine an evolutionary process in which (for example) the malleus and the stapes came first, and then the incus poofed into existence to fill the gap between them.

The sequence in the fossil record shows that we don't have to envisage a scenario where two of the three parts acquired their modern form and position first and then the third was tacked on. And even if you are a die-hard creationist and don't think that the fossil record is evidence of anything, nonetheless you must concede that we can see how the irreducibly complex system might have been produced by ordinary evolutionary modifications, and without two of the parts evolving and then the third being added.

Now, the first point of contention is if I find any convincing evidence that the reptilian ear did in fact become the mammalian ear, through a series of steps that natural selection would favor.

And this one of the problems your going to have if basing yourself on big anatomical features and transitions from the fossil record. You have to show a series of mutations that lead from one to the other, and you'll find it almost impossible to do using gross anatomical features such as bones, and even more using fossils instead of living animals, because at best you show 8 intermediates, in a transition that probably involves hundreds of mutations.

There is a distinct reason why IC systems in biology are analysed only at the biochemical level with the pieces being proteins and such, it is because the analysis of an advantageous mutational pathway to a IC system will be much, much, much more easier to discern.

But putting this aside, and supposing that I do accept that I see how this could have evolved, then I still see a blatant problem with this example, the three bones are already contributing to the hearing system of the reptiles:

In fact, even in modern reptiles the quadrate and articular serve to transmit sound to the stapes and the inner ear (see Figure 1.4.2).

http://www.talkorigins.org/...orphological_intermediates_ex2

And this strongly suggests to me, that this is an example of an already irreducibly complex system of three parts, where you modify the arrangements of the three parts and end up with a different version the same IC system that still does the same thing.

Let's take another example. Mammals have two jaws to grasp and chew their food with: an upper and a lower jaw. Remove one of these parts, and all function is lost --- one jaw is about as much use for chewing as one millstone is for grinding. This structure is therefore irreducibly complex.

So, what can we conclude? Clearly, this: that the evolution of this system can't have occurred by one jaw developing first and then the second one being added to make the complete system.

And guess what? No biologist anywhere ever has claimed that this happened. Instead, they trace the evolution of jaws from pharyngeal arches ("gill arches") which already had a lower and upper half before they functioned as jaws. Fossils of interest include the early chordates Yunnanozoon and Haikouella, which have no jaws but which possess pharyngeal teeth.

(Some modern fish also have pharyngeal teeth on the pharyngeal arches behind their jaws. Here's a picture of pharyngeal teeth in modern carp.

In cichlids, the lower left and right first pharyngeal arches have fused together to form a lower "pharyngeal jaw" behind the true jaw.)

Now, whether or not you accept the evolutionary explanation for this irreducibly complex structure, it's plain that the fact that it is irreducibly complex does nothing to argue against the evolutionary explanation, since the explanation does not involve the system evolving one jaw at a time, nor yet two fully-formed jaws simultaneously appearing at a single stroke, but rather the gradual processes of adaptation of form and function that one associates with the theory of evolution --- that is, with the actual theory of evolution, the one in biology textbooks, rather than the imaginary theory of evolution that must have been rattling around in Behe's head when he came up with this stuff about irreducible complexity.

Your explanation of all this is very difficult to understand, hopefully I understood it correctly.

In this case (once again, if I accept that I can see a possible pathway between fish gill arches and mammalian jaws) is that you start of once again with an upper and lower pieces already in the right place, and end up with these same pieces at the same places but this time changing function, and now serving as a jaw.

Another problem is, of course, that the jaw isn't a two piece system. It has many other pieces such as tendons, nervous circuits, etc. etc.

I would suggest, for the reasons mentioned earlier, that you stick to biochemical systems, and also because all the pieces of such systems and associated mutations are more easily identifyable. And of course, this will keep us on the terrain of experimental, presently observable processes and science, which is going to be easier for both of us to come to the same conclusions about those systems (contrary to fossils, which you can't expect of me to continually accept that there is a pathway between fossils just for the sake of the topic at hand)

As a final example, divide yourself (conceptually) into two parts --- your head and everything else. A series of experiments conducted by the French researcher Dr Joseph-Ignace Guillotin have proved conclusively that one is useless without the other. You yourself are an irreducibly complex system.

And this would be a strong objection to any evolutionary scenario involving a bunch of human heads rolling about without bodies for a few millenia; or, alternatively, a bunch of headless people strolling around and bumping into things.

But this is not the scenario that biologists have put forward. Instead, they suggest that the process involved gradual encephalization starting with a segmented ancestor whose frontmost segments played no special role.

Again, you can believe that or not; but it is no objection to this theory to point out that today the human head+body that represents one of the end points of that process forms an irreducibly complex system. It is only an objection to a hypothesis in which heads magically appeared on human bodies which previously had lacked them, or vice versa --- a hypothesis to which no-one at all subscribes.

This example tends to show that you aren't really interested in a genuine discussion, which was to expected I guess.

But say I take the example seriously. The basic irreducibly complex part of this is the IC aspect of multicellularity. It is a basic aspect of it that cells are interdependent and cannot survive without the others.

This in fact is a prime test for IC: if IC systems can evolve naturally, in no other area should we be able to better observe this then in the evolution of mulicellularity from unicellularity. The environment around us is filled with billions of unicellur organisms, of generation times in the span of minutes sometimes. If multicellularity was evolvable, then we should routinely observe every step of the process around us at any given time. We do not, and we do not observe it either in the fossil record, where multicellular organism appear all at once with no trace of the intermediates. Clearly, the only reasonable conclusion is that no paths exist for multicellularity, appart from mind-boggling randomness and luck, maybe.

Take your time to answer, as I have obviously taken more time then I planned.

AbE I know I am making some grand contentious claims here regarding multicellularity, but this was wanted to get the discussion in that direction, so you can drop any snarky comments you could plan up

Edited by slevesque, : No reason given.

Edited by slevesque, : No reason given.


This message is a reply to:
 Message 1 by Dr Adequate, posted 03-16-2011 6:59 AM Dr Adequate has responded

Replies to this message:
 Message 6 by Dr Adequate, posted 03-18-2011 7:46 PM slevesque has not yet responded
 Message 7 by Dr Adequate, posted 03-18-2011 9:23 PM slevesque has not yet responded

  
Dr Adequate
Member
Posts: 15960
Joined: 07-20-2006
Member Rating: 5.7


(1)
Message 6 of 17 (609382)
03-18-2011 7:46 PM
Reply to: Message 5 by slevesque
03-18-2011 5:05 PM


Now, the first point of contention is if I find any convincing evidence that the reptilian ear did in fact become the mammalian ear, through a series of steps that natural selection would favor.

Well no. As I said repeatedly about my examples, it makes no difference to the goodness of my argument or the badness of Behe's whether you believe this actually happened or not.

The point is simply that an evolutionary explanation need not involve the last step and final mutation being one that poofed the incus (for example) into existence fully-formed to fit between the malleus and the stapes.

Once we have taken note of this, we can see why Behe's argument fails.

You have to show a series of mutations that lead from one to the other ...

No, for the same reason. I don't have to show this at all. I have to argue that the last mutation was not necessarily one which poofed a fully formed part into place into a structure which was identical to the existing structure apart from missing that part.

Once I have done that, Behe's argument fails, and you are left with the old creationist evasion of: "Unless you can tell me exactly how this evolved in every slightest particular detail (something which the theory of evolution does not in any way predict that you should be able to do) then I refuse to believe that it evolved, so goddidit." And then it's not particularly an argument about irreducible complexity any more, since you could say that about any structure, and it does not become in any way less of a foolish thing to say if you're talking about IC systems then if you aren't.

But putting this aside, and supposing that I do accept that I see how this could have evolved, then I still see a blatant problem with this example, the three bones are already contributing to the hearing system of the reptiles:

Yes, but they're not necessary to do so --- as you can see from the diagram of the reptilian ear in the website you reference, the stapes alone will transmit vibrations from outside to inside the ear. And this is not true of the mammalian ear.

There is a distinct reason why IC systems in biology are analysed only at the biochemical level ...

Well, they aren't: I've often seen creationists put up examples of much higher-level systems. For example, here's a jolly little website calling itself "Evidences of Creation.com". They write:

For example, an ear perceives sounds only through a sequence of smaller organs. Take out or deform one of these, e.g. one of the bones of the middle ear, and there would be no hearing whatsoever. [...] Hence, the concept of irreducible complexity demolishes the theory of evolution at its foundations.

If they can use the bones of the middle ear as an example, then I think it's only fair that I can use them as a counter-example.

The reason why creationists will sometimes retreat to biochemical systems is that in that case there is no fossil evidence of what actually happened. But Behe has put up a perfectly general argument, so I don't see why I can't rebut it with any example of an IC system that I please.

... it is because the analysis of an advantageous mutational pathway to a IC system will be much, much, much more easier to discern.

Oh, you're doing this to make things easy for us?

You can stop doing us favors now.

Another problem is, of course, that the jaw isn't a two piece system. It has many other pieces such as tendons, nervous circuits, etc. etc.

I think it makes sense to analyze the jawbones as a system. Can you come up with some sensible criterion for a biological system such that this doesn't make sense?

In science, the customary usage of "system" is to denote something which can be analyzed without going into much detail about what lies outside the system, and I think the jawbones qualify --- we can think about their function in the organism without considering or caring whether they are moved by muscles and tendons controlled by nerves or by servo motors and springs controlled by fiber-optics.

(After all, the bacterial flagellum wouldn't do anything useful unless it was attached to the rest of the bacterium, and yet I don't hear any creationist complaining that that doesn't qualify as an example.)

This example tends to show that you aren't really interested in a genuine discussion, which was to expected I guess.

Why? Just because I threw in the occasional joke?

I don't see why I can't leaven the biology with a little humor.

The example itself is a perfectly good one. Your brain won't work without the rest of you, and the rest of you won't work without your brain, but that's only an argument that the whole system can't have evolved by the sudden and complete addition of the one to the previously existing other, not an argument that the system can't have evolved at all.

If multicellularity was evolvable, then we should routinely observe every step of the process around us at any given time.

In the first place, this is a non sequitur; in the second place the conclusion is not merely fallacious but false; in the third place we can observe multicellularity evolving; and in the fourth place I don't see what this has to do with IC.

We do not, and we do not observe it either in the fossil record, where multicellular organism appear all at once with no trace of the intermediates.

Where an intermediate would be what? An organism consisting of one-and-a-half cells?

(As a matter of fact, in our observations of the evolution of multicellularity the first step is not even from one cell to two. But again we seem to be straying from the topic.)

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 5 by slevesque, posted 03-18-2011 5:05 PM slevesque has not yet responded

Replies to this message:
 Message 8 by slevesque, posted 03-21-2011 4:42 PM Dr Adequate has responded

  
Dr Adequate
Member
Posts: 15960
Joined: 07-20-2006
Member Rating: 5.7


Message 7 of 17 (609386)
03-18-2011 9:23 PM
Reply to: Message 5 by slevesque
03-18-2011 5:05 PM


You have to show a series of mutations that lead from one to the other ...

To elaborate on my previous comments.

Take practically any historical claim, for example that Hannibal led elephants across the Alps.

Suppose someone was to say since I can't give a detailed and provably accurate account of every step taken by every elephant, it is more likely or as likely that if Hannibal's army entered Italy at all, they must in fact have been teleported across the Alps by the Phoenician god Moloch. What would we say?

(1) We would say that he was being excessively credulous, because there is no particular evidence for the Moloch hypothesis --- and because natural events are more common than supernatural events.

(2) We would say that he was being excessively skeptical because there is nothing in the conventional theory that implies that we would know Hannibal's route of march to this level of detail no matter how true the conventional theory is.

And, as I said, this has nothing to do with IC as such because you can apply this same bad argument to pretty much any historical event you want to cast unreasonable doubt on, whether it is the evolution of an IC system, or the evolution of a non-IC system, or Hannibal crossing the Alps. The fact that you can apply this argument to IC systems just as well (or badly) as to anything else does nothing to bolster Behe's argument concerning them.

Behe's argument is (to continue my analogy) like claiming that Hannibal can't have led elephants across the Alps because it's not possible for elephants to go uphill. Once I've refuted that, the additional argument that I can't provide the precise route of march does nothing to rescue the original argument, since it has no bearing on the question of whether or not elephants can go uphill, and indeed could be made just as well of an army that was totally free of elephants. It is not, then, a rebuttal to my rebuttal, it's just a violent relocation of the goalposts.

We might note that we never see an evolutionist seriously casting doubt on creationism on the grounds that you guys can't say whether God made aardvarks before anteaters, or whether he started sculpting Adam at the head or at the toes: because we have no need of bad arguments, and because we recognize that there is nothing about the creationist hypothesis which suggests that we should be able to acquire that level of detailed knowledge about creation even if creationists were absolutely right.

Edited by Dr Adequate, : No reason given.

Edited by Dr Adequate, : No reason given.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 5 by slevesque, posted 03-18-2011 5:05 PM slevesque has not yet responded

Replies to this message:
 Message 9 by slevesque, posted 03-21-2011 4:54 PM Dr Adequate has responded

  
slevesque
Member (Idle past 2196 days)
Posts: 1456
Joined: 05-14-2009


Message 8 of 17 (609610)
03-21-2011 4:42 PM
Reply to: Message 6 by Dr Adequate
03-18-2011 7:46 PM


Well no. As I said repeatedly about my examples, it makes no difference to the goodness of my argument or the badness of Behe's whether you believe this actually happened or not.

The point is simply that an evolutionary explanation need not involve the last step and final mutation being one that poofed the incus (for example) into existence fully-formed to fit between the malleus and the stapes.

Once we have taken note of this, we can see why Behe's argument fails.

The thing is, that thinking that it did happen is the only way of thinking that it could happen, in this particular case of using fossil evidence (I'm highlighting this so you don't take the previous out of context), because you haven't actually demonstrated a step by step pathway in which each step is favoured by natural selection.

No, for the same reason. I don't have to show this at all. I have to argue that the last mutation was not necessarily one which poofed a fully formed part into place into a structure which was identical to the existing structure apart from missing that part.

But no one is claiming this, and wanting to represent Behe as if this is what he's claiming is clearly fallacious.

The thing is, the mechanism you are proposing to explain IC systems is not some sort of continuous morphing, but a step by step process fo mutations and Selection.

Yes, but they're not necessary to do so --- as you can see from the diagram of the reptilian ear in the website you reference, the stapes alone will transmit vibrations from outside to inside the ear. And this is not true of the mammalian ear.

Two unsupported assertions, unfortunately.

Oh, you're doing this to make things easy for us?

You can stop doing us favors now.

It is to make it easy for us, meaning the both of us.

Keep in mind, I have no personnal investment in the idea of IC, my worldview functions perfectly well without it, and it's not my idea. If it were to be shown to be unreliable I would gladly conclude so. Note that in the two years I have been here, this is the first time I discuss this subject, and this was only because someone foolishly (in my opinion) claimed that it had been ''utterly and completely demolished'', showing that I myself am hesitant to put much weight to it, and that my intention is to show that, at the very least, credit is to be given were credit is due, and that Behe does not deserve to be treated like a complete idiot.

I think it makes sense to analyze the jawbones as a system. Can you come up with some sensible criterion for a biological system such that this doesn't make sense?

Well, first I don't see how the two jawbones could perform functions on their own, functions such as, you know, chewing.

(After all, the bacterial flagellum wouldn't do anything useful unless it was attached to the rest of the bacterium, and yet I don't hear any creationist complaining that that doesn't qualify as an example.)

In counter-part, that is because all the relevant pieces for the flagellum to perform it's function are being considered into the system. You can't say the same about your two-piece jaw system

In the first place, this is a non sequitur; in the second place the conclusion is not merely fallacious but false; in the third place we can observe multicellularity evolving; and in the fourth place I don't see what this has to do with IC.

This is directly related to IC, because the IC nature of multicellular systems is what makes the crude example of ''head and body'' an IC system.

Where an intermediate would be what? An organism consisting of one-and-a-half cells?

(As a matter of fact, in our observations of the evolution of multicellularity the first step is not even from one cell to two. But again we seem to be straying from the topic.)

The advent of life, and coordinated multicellularity are two points where we can agree (I hope) that it is clear that they are the advent of IC systems.

Multicellularity arises when the selection is made at the level of the organism, not at the level of the individual cells, and reproduces as a single organism.

These two areas, the origin of life, and the origin of multicellularity are of particular interest because we should be able to observe every single step all around us. It should like being in a forest, where you don't need to see a tree's entire life to know each steps it goes through because of the vast amount of trees around you, where each tree is at a different stage. (Same analogy with stellar evolution)

Edited by slevesque, : No reason given.


This message is a reply to:
 Message 6 by Dr Adequate, posted 03-18-2011 7:46 PM Dr Adequate has responded

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slevesque
Member (Idle past 2196 days)
Posts: 1456
Joined: 05-14-2009


Message 9 of 17 (609612)
03-21-2011 4:54 PM
Reply to: Message 7 by Dr Adequate
03-18-2011 9:23 PM


You do know that argument by analogy is fallacious reasoning, even though it is helpful to sometimes illustrate a discussion.

In this case, the analogy clearly does not apply. You are making the claim that there exists a pathway of single mutations, where as each step is favored by natural selection to go from one to the other.

In other words, you are making a claim about the mechanism it happened by. Not the historicity of the event. Behe, being a theistic evolutionists, would agree with you that mammals descended from reptiles and the fossil evidence for this, but he would disagree on the mechanism.

Edited by slevesque, : No reason given.


This message is a reply to:
 Message 7 by Dr Adequate, posted 03-18-2011 9:23 PM Dr Adequate has responded

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Dr Adequate
Member
Posts: 15960
Joined: 07-20-2006
Member Rating: 5.7


Message 10 of 17 (609634)
03-21-2011 8:12 PM
Reply to: Message 8 by slevesque
03-21-2011 4:42 PM


The thing is, that thinking that it did happen is the only way of thinking that it could happen ...

Not at all. Indeed, I am asking you to concede that it could happen without asking you to concede that it did. Given that evolution can occur (which you must assume for the sake of argument, or we're having a completely different discussion) then the bones could have changed their shapes and their positions relative to one another and to the dentary and squamosal bones.

Whether or not they did we may leave aside. But the fact that they could have invalidates Behe's argument.

But no one is claiming this, and wanting to represent Behe as if this is what he's claiming is clearly fallacious.

Behe doesn't claim that that's how evolution occurs, no. But that's the only sort of evolution that the fact that a structure is IC is an argument against. All that that tells us is that the evolutionary process can't have happened such that the last stage in the production of an IC structure of n parts was the "poofing" of the nth part.

In order to make Behe's argument into an argument against the evolution of IC systems, you would have to add the false premise that this is the only way that evolution can occur.

(Someone who says that it's impossible to travel from Europe to America because:

(a) the sea is in the way
(b) people can't walk on water

is not thereby explicitly denying the existence of modes of transport other than walking, but he would need to add the false premise that journeys can only be made on foot in order for his conclusion to actually follow from the premises. To point this out is not to misrepresent his argument, but to analyze it.

It is then no defense of his argument to point out that he didn't say, or even that he doesn't believe, that journeys can only be made on foot, because whether or not he said it and whether or not he believes it, his argument still requires the false premise.

Nor, I might add, is it a defense of his reputation. You would be doing nothing for him by saying: "He's not a fool, he does know that planes and ships exist", because if he does know that then he is a fool --- for putting up his argument in despite of that knowledge.)

Two unsupported assertions, unfortunately.

They're supported by the diagrams. You can see for yourself that in the reptilian ear the stapes on its own makes a bridge across the middle ear; in mammals the stapes, incus, and malleus are required for a complete bridge.

Well, first I don't see how the two jawbones could perform functions on their own, functions such as, you know, chewing.

In counter-part, that is because all the relevant pieces for the flagellum to perform it's function are being considered into the system.

Well, no. The same question could be asked about the flagellum as about the jawbones --- where's the power source? But in both cases we do not need to know very specific details about what the power source is. The flagellum (I presume) needs some sort of chemicals; the jawbones require a source of mechanical force.

I maintain that both can be considered "systems". It's not that they don't require anything else to do their job, it's that we can largely ignore the details of what that thing is. And this is in fact more true of the jawbones than the flagellum.

This is directly related to IC, because the IC nature of multicellular systems is what makes the crude example of ''head and body'' an IC system.

Then let my "crude example" be paradigmatic for the general answer. We don't need to envisage any of our differentiated tissues (the liver, say, or the kidneys) suddenly "poofing" into an organism which couldn't have got by without them.

These two areas, the origin of life, and the origin of multicellularity are of particular interest because we should be able to observe every single step all around us. It should like being in a forest, where you don't need to see a tree's entire life to know each steps it goes through because of the vast amount of trees around you, where each tree is at a different stage.

Well, we certainly shouldn't be able to see every step of the origin of life around us, that should be completely impossible; and you have not made it clear what you mean by "steps" in multicellularity. We can see organisms with one cell, we can see organisms with two cells ...

Edited by Dr Adequate, : No reason given.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 8 by slevesque, posted 03-21-2011 4:42 PM slevesque has not yet responded

  
Dr Adequate
Member
Posts: 15960
Joined: 07-20-2006
Member Rating: 5.7


Message 11 of 17 (609647)
03-21-2011 9:34 PM
Reply to: Message 9 by slevesque
03-21-2011 4:54 PM


You do know that argument by analogy is fallacious reasoning, even though it is helpful to sometimes illustrate a discussion.

In this case, the analogy clearly does not apply. You are making the claim that there exists a pathway of single mutations, where as each step is favored by natural selection to go from one to the other.

In other words, you are making a claim about the mechanism it happened by. Not the historicity of the event. Behe, being a theistic evolutionists, would agree with you that mammals descended from reptiles and the fossil evidence for this, but he would disagree on the mechanism.

Which makes him like a man who maintains that Hannibal and his army did indeed enter Italy but did so by being teleported over the Alps by Moloch; as opposed to the conventional creationist who is like a man who believes that Hannibal never crossed the Alps but that since the beginning of history there was always an army of Phoenicians with elephants on the Italian side of the Alps.

Both these people would be equally well (or badly) served by the argument that elephants can't go uphill and by the argument that I can't describe every step of the route they took.

But if you don't like the analogy, leave it be. My point, which I hope you will concede, is:

(1) That it is pointless to cavil at the reality of any historical event by pointing out that we do not know about it to a level of detail which we would not in fact possess even if the event occurred.

(2) That such an argument does not support the argument that such an event is impossible; to be sure, they are both arguments against the same event, but the argument from lack of detail does not support the impossibility argument as such.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 9 by slevesque, posted 03-21-2011 4:54 PM slevesque has not yet responded

  
Dr Adequate
Member
Posts: 15960
Joined: 07-20-2006
Member Rating: 5.7


Message 12 of 17 (609662)
03-22-2011 1:49 AM
Reply to: Message 9 by slevesque
03-21-2011 4:54 PM


Analogical Logic
You do know that argument by analogy is fallacious reasoning, even though it is helpful to sometimes illustrate a discussion.

Pointing out the formal resemblance between two arguments having the same logical form is not fallacious; it is a powerful tool in our cognitive toolbox.

For example, suppose someone reasons as follows:

No humans have tails.
Slevesque has no tail.
Slevesque is human.

In order to convince him that despite the fact that he accepts the conclusion there is still something formally wrong with this argument I might propose the following argument having the same form:

No pig has wings.
You have no wings.
You are a pig.

Now, if he finds something wrong with the conclusion, as he will, then he is bound to admit that there is something wrong with the form of his argument, since the parts of the first argument bear the same logical relationship to one another as do the parts of the second argument.

And you, slevesque, would surely not object to such a procedure as a fallacious argument from analogy.

Now what I have done by my "analogy" of elephants crossing the Alps is to use it as an illustration of the general relationship which exists (or does not exist) between the propositions:

(a) It is contrary to the laws of nature for X to occur.
(b) You cannot tell me in every last detail how X did occur.

Now if anything in my illustration had depended on specific premises about elephants or Carthaginians which had no corresponding premise in the reasoning concerning IC systems, then you would be right to complain that I was myself guilty of a fallacious argument, because then the formal correspondence would break down --- but it didn't so you shouldn't.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 9 by slevesque, posted 03-21-2011 4:54 PM slevesque has not yet responded

  
Dr Adequate
Member
Posts: 15960
Joined: 07-20-2006
Member Rating: 5.7


Message 13 of 17 (610623)
03-31-2011 4:20 PM


Bump
I was wondering if you had anything to say.

Let me summarize what I've said so far.

Behe's argument is that an irreducibly complex system of n parts can't have evolved because natural selection would not have favored the evolution of the first n-1 parts of the system, because the first n-1 parts of the system would have conferred no selective advantage to the organism until the nth part was added to the system.

However, this argument would only apply if the only conceivable final step in the evolution of the system involved the wholesale addition of the nth part to a system which, besides lacking the nth part, was otherwise identical to the final system. Which is not necessarily the case, and is certainly not how evolutionists maintain that evolution works.

In order to invalidate Behe's argument as it stands, I do not have to definitively prove that any irreducibly complex system evolved by another route and specify it --- I only have to point out that we can conceive of other possible routes.

By analogy, if someone says: "A burglar couldn't possibly have got into the house, therefore the robbery must have been an inside job" then I can refute that argument as it stands by pointing out that he could have got in through the unlocked back door, the unlocked front door, or the open ground-floor window. In order to refute the impossibility argument as it stands, I do not have to prove:

(a) That the burglar did take one of those routes.
(b) That we can be certain which of those routes he took.
(c) That there was a burglar and that it wasn't an inside job.

Instead, I have refuted the impossibility argument as such when I have shown that there are possible routes that a burglar could have taken into the house.

This does not, of course, solve the crime. Maybe it was an inside job and maybe one day the detective will prove it. But it does show that the argument from impossibility is flawed and that therefore this argument does not prove, nor even support, the hypothesis that the crime was an inside job.

Edited by Dr Adequate, : No reason given.


Replies to this message:
 Message 14 by slevesque, posted 03-31-2011 5:13 PM Dr Adequate has responded

  
slevesque
Member (Idle past 2196 days)
Posts: 1456
Joined: 05-14-2009


Message 14 of 17 (610635)
03-31-2011 5:13 PM
Reply to: Message 13 by Dr Adequate
03-31-2011 4:20 PM


Re: Bump
Hi Dr.A,

Sorry end of semester studying is underway, but I haven't forgotten this.

In fact I have been reading 'Irreducible complexity revisited' (http://www.designinference.com/....Irred_Compl_Revisited.pdf) in my spare time and I have just finished reading it.

I'll be posting a reply hopefully tomorrow. I guess you can read Dembski's paper if you have the time, it would help the discussion


This message is a reply to:
 Message 13 by Dr Adequate, posted 03-31-2011 4:20 PM Dr Adequate has responded

Replies to this message:
 Message 15 by Dr Adequate, posted 03-31-2011 5:28 PM slevesque has not yet responded
 Message 16 by Dr Adequate, posted 03-31-2011 6:05 PM slevesque has not yet responded

  
Dr Adequate
Member
Posts: 15960
Joined: 07-20-2006
Member Rating: 5.7


Message 15 of 17 (610640)
03-31-2011 5:28 PM
Reply to: Message 14 by slevesque
03-31-2011 5:13 PM


Re: Bump
Sorry end of semester studying is underway, but I haven't forgotten this.

Oh. Best wishes then. I remember what that's like ...

I'll have a look at Dembski's paper, although since I'm a mathematician and not a biochemist my opinion of Dembski is much much lower.


This message is a reply to:
 Message 14 by slevesque, posted 03-31-2011 5:13 PM slevesque has not yet responded

  
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