Why the Flagellum is Irreducibly Complex Despite Potential Indirect Pathways
An IC machine cannot, by definition, be the result of a direct Darwinian pathway which is gradualistic. Direct means that the steps are selected for the improvement of the same function we find in the final machine. IC deals ONLY with Direct pathways, but does not rule out Indirect pathways. An Indirect Darwinian pathway is a series of small changes which have to come about independently, each having positive selective pressure for a different type of function, and then they all indirectly come together to form a new whole. The reason a Direct Darwinian pathway is not an option is due to Irreducible Complexity since a Direct Pathway requires that a component have positive selective pressure for its function every increment.
But the reason the flagellum is IC is because until all components are in place it is not functional. Darwinists do not like to tacitly admit that IC is a factor but that is why all current research is now directed upon Indirect Darwinian pathways. Unfortunately for Darwinists, that type of scenario is essentially relying on serendipity.
IC makes a direct Darwinian pathway impossible. So, only two possibilities are left: either sudden appearance of the complete machine (practically impossible for statistical considerations), or step by step gradual selection for different functions, and with the target function COMPLETELY INACTIVE for natural selection. This is a point that Darwinists tend to bypass. Darwinists may believe in Indirect Darwinian pathways, because it's the only possible belief which is left for them, but it's easy to see that it really means believing in impossibilities. There is no reason in the world, either logic or statistical, why a complex function should emerge from the sum of simpler, completely different functions. And even granted that, by incredible luck, that could happen once, how can one believe that it happened millions of times, for the millions (yes, I mean it!) of different IC machines we observe in living beings? The simple fact that Darwinists have to adopt arguments like co-option and indirect pathways to salvage their beliefs is a clear demonstration of how desperate they are.
Mechanical components of all life are Irreducibly Complex (IC). Not all components are IC nor do they qualify as Complex Specified Information (CSI). The question is whether unguided Darwinian processes (RM+NT, lateral gene transfer, symbiogenesis, reliance on hox genes, whatever) can produce IC and/or CSI components via Indirect Pathways. Unguided Darwinian processes perhaps are estimated (not observed) to be capable of producing components that are composed of 3-6 parts at most. But for comparison the flagellum is composed of 41 parts and the most observed we've ever heard of is 2. Again, part of ID research is determining the limits of unguided Darwinian processes. Agreeing that there are beneficial mutations and limited instances of small changes is in no way a threat to ID or an admission of some sort we have been saying this for years to deaf ears.
Also, as far as I'm aware even the Darwinists who are experts on the flagellum have not been able to concoct a hypothetical Indirect pathway that is workable from a practical perspective. The most they've done is analyze the sub-components of the flagellum and look for other objects that have similar feature but are being used for different functions (homologies). The idea is that all the sub-components necessary for the entire flagellum will evolve separately from each other. Each sub-component will be favored by natural selection for their separate functionality. And then somehow these sub-components will come together.
Now an Indirect Darwinian pathway for the flagellum would not only require that the code for various components come together (be co-opted), but that the code regulating that code be modified, the location/orientation be precise, modifications be made to the original code for these components, and that new code be generated. The reason new code is needed is because not all the components in the total system may have homologs or functions separate from the whole. For the flagellum there are currently 17 unique proteins with no known homologs (by the way, the T3SS and the subsystem in the flagellum are similar but not exactly the same; Behe is researching protein binding sites to see if there are limitations that may make indirect pathways not just unlikely but impossible). Then of course there are the external systems for controlling the usage of the flagellum…kinda useless to have an outboard motor but no way of using it. Never mind overcoming the pleiotropic nature of this code, since making these changes can and will often have adverse effects. As in, in order to have positive selection the changes being made not only have to pull together a functional flagellum but they can't have a negative effect that is worse than the positive of having the functional flagellum.
Of course, they're having trouble just showing how these sub-components would evolve by Darwinian mechanisms in the first place. In its own right, the T3SS is fairly complicated, being comprised of 11 proteins. The problem Darwinists face is that Darwinian mechanisms have never been shown capable of even producing a system like the T3SS, never mind the full flagellum.
Now your Darwinist friend is probably arguing the flagellum is not IC based upon a misunderstanding of IC. His argument probably goes like this:
"In the Flagellum Behe Ignores that this Organization of Proteins has Verifiable Functions when Particular Proteins are Omitted, i.e. in its simplest form, an ion pump."
Yes, the ion pump as a sub-component of the entire flagellum assembly has a completely separate function and could potentially be used in a different machine with a different overall function. But an IC machine cannot, by definition, be the result of a direct Darwinian pathway. Direct means that the steps are selected for the improvement of the same function we find in the final machine. The ion pump is necessary for the overall flagellum to function but attaching other sub-components to it in a gradual/stepwise direct pathway will not create a flagellum until all the pieces are in place. The very fact that this Darwinist would even attempt to make this argument showcases that his comprehension of IC is in error!
This argument could be compared to saying that a bike is not IC since a sub-component like the chain could serve a different function in another mechanical device.
BTW, it's not as if Darwinists invented Indirect Darwinian pathways in response to Behe. Behe himself said way back in the 1990s that the only way for Darwinian mechanisms to evolve an IC machine was through Indirect pathways! The issue is not whether the flagellum is IC. It is. Stating something to be IC is NOT a claim that it cannot evolve in principle. The real issue is whether Indirect pathways are realistic.
ID proponents have been saying for years that Darwinian mechanisms are NOT toothless. They DO function but there is no positive evidence they are capable of producing objects that are IC or CSI. Try reading Behe's recent book Edge of Evolution. Behe examines multiple samples that are well within the limitations of Darwinian mechanisms.
Also:
http://www.amazon.com/gp/blog/post/PLNK2LJVF3SRXVK9O
ID proponents have been saying for years that Darwinian mechanisms are NOT toothless.
I suppose that depends on the proponent. It is a big tent after all.
Try reading Behe's recent book Edge of Evolution.
I have to observe that brush-offs like this don't really contribute to increasing traffic around here.
That was not a brush off. Behe's intention with his book was to examine examples of what Darwinian mechanisms are known to be capable of.
terryf wrote:
"I suppose that depends on the proponent. It is a big tent after all."
Tell me, terryf… in your view, is it a good thing or a bad thing that ID can be characterized as a "big tent"?
Would a "small tent" be better than a "big tent"? Or vice-versa? And why?
Just curious.
TRoutMac
Intelligent (Graphic) Designer
Tell me, terryf… in your view, is it a good thing or a bad thing that ID can be characterized as a "big tent"?
It is a bad thing. When it becomes a necessity, in order to hold the big tent together, to ignore relevant scientific questions like common descent and the age of the earth, ID has ceased to be a scientific enterprise and has become a socio-political coalition built on the premise that "the enemy of my enemy is my friend."
Do you think that such scientific disagreements should be put aside for the greater good of supplanting evolution? If you do, please introduce yourself to Barry Arrington who recently stated "it seems to me that compromise does not fit in well with the quest for scientific truth."
Thank you, terryf, for confirming my suspicions. Having answered my question, permit me to revisit the flow of this thread briefly:
terryf wrote:
"Is there any biological feature that you would state is most easily explained by evolution and not intelligent design?"
To which Patrick replied:
"ID proponents have been saying for years that Darwinian mechanisms are NOT toothless."
Now there's no excuse for even a minimally-informed participant in this debate to not be aware that ID proponents and even Young Earth Creationists recognize that natural selection and random mutations can account for quite a few biological features. No excuse.
So having had your ignorance laid bare, rather than letting Patrick's reply actually have an impact your opinion of ID, rather than admitting that your understanding was in error, you impugn ID by calling it a "big tent".
The only reason ID is a "big tent" with respect to the particular topics you raise is because people in the ID movement actually have respect for the limitations of science. If you think that ID should have a position on the age of the Earth, if you think that ID should reject common descent by definition, then it is you who want ID scientists to allow their religious and philosophical beliefs to interfere with their scientific conclusions. Don't you just love that? Oh… the irony!!
Understand this, terryf: Intelligent Design theory states that biological life was designed. Period. It doesn't say how long ago it was designed. Nor does it say to what extent evolutionary processes were employed in that design. If Intelligent Design was what you no doubt think it is, then it would not be a "big tent". The fact that it is a 'big tent' just proves that it's not driven by religion and philosophy like Darwinism is.
terryf wrote:
"Do you think that such scientific disagreements should be put aside for the greater good of supplanting evolution?"
This is a stupid question and reveals further the depths of your ignorance and stubborn assumptions about ID. Those issues are set aside because they are irrelevant to the broader question of whether something is the product of intelligent design… they aren't set aside "for the greater good of supplanting evolution."
How ridiculous. Where do you people get such nonsense?
TRoutMac
Intelligent (Graphic) Designer
"Do you think that such scientific disagreements should be put aside for the greater good of supplanting evolution?"
This is a stupid question and reveals further the depths of your ignorance and stubborn assumptions about ID. Those issues are set aside because they are irrelevant to the broader question of whether something is the product of intelligent design… they aren't set aside "for the greater good of supplanting evolution."
How ridiculous. Where do you people get such nonsense?
Mainly from looking at the spectrum of statements by ID proponents, who can't seem to come to any consensus as to what ID is. Behe accepts common descent, but thinks the designer is tinkering around at the subcellular level (like with the flagellum.) However, Kenyon and Davis don't agree, saying that "Intelligent design means that various forms of life began abruptly through an intelligent agency, with their distinctive features already intact - fish with fins and scales, birds with feathers, beaks, and wings, etc." And when it was designed is a relevant question to the extent that we need to make the leap from micro to macro.
Ya'll are anti-evolutionists. I get that. But, if you wish to replace evolution as an explanatory model you are going to have to get away from this incoherent mish-mash of constituencies drawn together not by a consilient view of the life sciences, but only by a common adversary.
I suppose you are right that I don't understand ID. But, not having drunk either sides kool-aid, and having adopted a deistic philosophy, I would like to think I am open to coherent, and consilient, explanations. I just don't see it. The only agreement I see in the big tent is that "evolution can't do it." Well, color me underwhelmed.
And frankly, Troutmac, I am not sure I am interested in continuing this discussion. Patrick wishes me to buy a book as price of admission. And you only seem to be interested in shouting people down rather than engaging in conversation. So, consider the final word ceded. Revel in your great victory over the evolutionist you have decided that I am.
Essentially you are asking for a book-length response in a forum. There are various internet-based information sources but unfortunately so far there is nothing that explains ID as well as the books (which I've often said to be a bad thing). But I'll try and give a very short response:
ID theory at its core is about design detection.
“...even though in practice inferring design is the first step in identifying an intelligent agent, taken by itself design does not require that such an agent be posited. The notion of design that emerges from the design inference must not be confused with intelligent agency” (Dembski, The Design Inference, 227)
In short, we use the design inference to recognize the credible existence of design.
Now there are many ID-compatible hypotheses, which are supported by various groups in the "big tent".
For example, there are multiple variants of "front loading".
1. Design was implemented in the universe itself. Everything is deterministic, and a plan rolled out from the initial implementation.
2. Design is not only in the universe and its laws but in the Origin Of Life (OOL). Darwinian mechanisms are taken into account by the Designer(s) and the architecture of life itself is configured to be modular, so that multi-functionality, gene duplication, cooption, and preadaptation, etc. are able to unmask secondary information. Of course, this presumes that Darwinian mechanisms are capable of this task, for which we have no positive evidence.
3. Same as 2 except there is a specific plan encoded into the original life and Darwinian mechanisms play less of a role, only being capable of producing minor variation.
4. Same as 2 or 3 except that there are multiple instances of Design (multiple Origins Of Life) occurring at the level of kingdom or phylum.
5. Essentially 2 - 4 except with the addition of Designer Intervention for certain information that is/was not modular but specific to a particular organism.
Some might want ID to “officially” incorporate a particular ID-compatible hypothesis in order to be considered “science”. Personally I think that research into all the hypotheses should be encouraged and it’s way too early to be declaring one to BE ID.
But once we have firmly identified the mechanism (how did the actor act?) we might be able to glean more information to identify the classification of the Designer(s) using different methods than core ID. Given a classification, we could then narrow the search.
terryf wrote:
"Ya'll are anti-evolutionists. I get that."
Your moniker has been around here a quite long enough for you to know better than to offer this statement. Nobody here is an "anti-evolutionist." It's been explained at least a million times that ID and evolution are not mutually exclusive. I said in my last post, which presumably you read, that not even Young-Earth Creationists could properly be categorized as "anti-evolutionists." Even after reading that (again, presumably) you persist with the nonsense that IDers are "anti-evolutionists" and that you "get that." How might I explain this?
And neither is anyone here "shouting you down." The fact that you would persist yet again in characterizing ID proponents as "anti-evolutionists" merely vindicates the frustration in my previous post. You're not paying attention to what you read here, plain and simple. You're not getting it. We're not "anti-evolutionists." That you persist in these ill-informed characterizations only demonstrates that you have indeed been drinking a fair amount of Kool-Aid.
TRoutMac
Intelligent (Graphic) Designer
So let me summarize to make sure I understood it right:
By definition, an IC component is one that cannot evolve because any simplified version (found by removing components) is non functional.
Neo-darwinists counter that such a structure might have evolved from another simpler component which had a completely different purpose.
But this argument fails, simply because:
a) The hypothetical simpler structure may also be IC, thus presenting the evolutionist with two problems where he previously had just one.
b) This results in a tautology, simply because we have already defined an IC structure as one which cannot be degraded in this kind of way.
The brilliance of this line of thinking, is that even if the evolutionist were to present a complete evolutionary pathway from a single protein all the way to a complex structure (e.g. a flagellum), showing every intermedate step, this would result in a massive own-goal.
They would simply have dug them into a deep hole with not one but potentially hundreds of IC structures, each of which would need to be explained away. They are not even close to that for flagellum, let alone the whole 'tree of life'.
I'm going to blog about this article, but I want to be sure I understood it correctly. I'm not the most technical of people, so I thank you for your patience.
HeLa
IC or not?
Is there any biological feature that you would state is most easily explained by evolution and not intelligent design?