|
Register | Sign In |
|
QuickSearch
Thread ▼ Details |
|
Thread Info
|
|
|
Author | Topic: Behe's Irreducible Complexity Is Refuted | |||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: Nope, doesn't even touch Behe's argument since the ossicles don't form an IC system. If someone is going to refute Behe, they need to stick to systems that meet Behe's criteria.
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: The function of the ossicles is hearing? Really? That's news to me. If someone is going to claim that a given system meets Behe's definition of IC, one of the first things he/she must do is identify the function of the proposed system. So, what is it? (And no, it's not hearing: the ossicles alone do not produce hearing). PS: I don't know why people don't stick to the systems Behe mentioned in his book: supposedly, he's been refuted on them. [This message has been edited by DNAunion, 03-08-2004]
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: We need to talk about one system at a time. I didn't read all the posts in this thread, but it was my impression that it was the ossicles that were claimed to be an IC system, not the complete hearing system. So I guess before we agree on the function of the system, we must first agree on what the system is. So everyone, what is the actual system under consideration?
quote: But I didn't say that. I said the function of the ossicles themselves is not hearing, and that is correct.
quote: The burden of proof is upon those who claim it is IC. Now, for them to assert that system X is IC, they must be able to identify the function of the system...they also need to be able to identify the system under consideration. [This message has been edited by DNAunion, 03-08-2004]
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: So your "Refutation" of Behe is that a PART of an (alleged) IC system can evolve? How does that refute Behe?
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: No, I'm not saying that...I know what they do: I want those making the claims to state it themselves, clearly and unambiguously, so there's no moving the goal posts later. But first, is it the ossicles or is it the complete hearing system that's under discussion? [This message has been edited by DNAunion, 03-08-2004]
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: I’m curiouswhere did you hear that actin is involved in flagellar motion? Was it Kenneth Miller? He’s made the claim that actin is a major component of cilia, being involved in ciliary motion. But to the best of my knowledge, it doesn’t. Here’s some of my personal notes on this
quote: and
quote: DNAunion: Miller twice mentions the protein actin and calls it a major component of a cilium. But Behe doesn’t even mention actin when discussing the cilium, so why is Miller bringing that protein into the discussion as if it were one that Behe considered to be a required part? Actually, it’s worse for Miller than that: actin is not a major component of cilia. You see, Behe is not the only scientist who doesn’t mention actin when discussing cilia. Over the last couple of days I have read dozens of pages about cilia and microtubules from two molecular cell biology texts and nowhere do I recall any mention of actin (in microfilaments, yes; microtubules, no. in motility by muscular contraction, yes; motility by cilia, no). But before claiming Miller to actually be wrong, I wanted to make double sure, so I spent several hours carefully rereading every sentence of the pertinent sections of both molecular cell biology texts. Here are the topics I reread in full. The World of the Cell: Third Edition: Wayne M. Becker, Jane B. Reece, and Martin F. Poenie, Benjamin/Cummings Publishing Co., 1996 Chapter 20: Cytoskeletal Structure and Function ---Introduction (p644) ---Structural Elements of the Cytoskeleton (p644-645) ---Microtubules (p648-659) ------Introduction ------Structure and Polarity of Microtubules ------The Genetics of Microtubules ------Microtubule Assembly in Vitro ------The Dynamic Instability Model of Microtubule Assembly ------Drug Sensitivities of Microtubule Assembly ------Microtubule Organization, Function, and Regulation in the Cell ------Organization and Maintenance of Cell Shape ------The Role of Dynamic Instability and Capping Proteins in Microtubule Organization ------Regulation of Microtubules by Microtubule-Associated Proteins Chapter 21: Cellular Movement: Motility and Contractility---Introduction (p675) ---Systems of Motility (p675) ---The Molecular Basis of Motility (p675-676) ---Intracellular Microtubule-Based Movement: Dynein and Kinesin (p678-680) ------Cytoplasmic Microtubules, Motor MAPs, and Axonal Transport ------Motor MAPs and the Transport of Intracellular Vesicles ---Microtubule-Based Motility: The Motile Appendages of Eukaryotic Cells (p702-706) ------Cilia and Flagella ------The Structure of Motile Appendages ------The Sliding-Microtubule Model for Motile Appendages ---The Bacterial Flagellum (p706-709) ------Nature’s Wheel: Locomotion by Rotation ------Flagellar Rotation and Chemotaxis Molecular Cell Biology: Fourth Edition: Harvey Lodish, Arnold Berk, S. Lawrence Zipursky, Paul Matsudaira, David Baltimore, and James Darnell, W. H. Freeman and Co., 2000Chapter 19: Cell Motility and Shape II: Microtubules and Intermediate Filaments ---Introduction (p795-796) ---Microtubule Structures (p796-802) ------Introduction ------Heterodimeric Tubulin Subunits Compose the Wall of a Microtubule ------Microtubules Form a Diverse Array of Both Permanent and Transient Structures ------Microtubules Assemble from Organizing Centers ------Most Microtubules Have a Constant Orientation Relative to MTOCs ------The [gamma]-Tubulin Ring Complex Nucleates Polymerization of Tubulin Subunits ---Microtubule Dynamics and Associated Proteins (p802-809) ------Introduction ------Microtubule Assembly and Disassembly Occur Preferentially at the (+) End ------Dynamic Instability Is an Intrinsic Property of Microtubules ------Colchicine and Other Drugs Disrupt Microtubule Dynamics ------Assembly MAPs Cross-Link Microtubules to One Another and Other Structures ------Bound MAPs Alter Microtubules Dynamics ---Kinesin, Dynein, and Intracellular Transport (p809-817) ------Introduction ------Fast Axonal Transport Occurs along Microtubules ------Microtubules Provide Tracks for the Movement of Pigment Granules ------Intracellular Membrane Vesicles Travel along Microtubules ------Kinesin Is a (+) End-Directed Microtubule Motor Protein ------Each Member of the Kinesin Family Transports a Specific Cargo ------Dynein Is a (-) End-Directed Motor Protein ------Dynein-Associated MBPs Tether Cargo to Microtubules ------Multiple Motor Proteins Are Associated with Membrane Vesicles ---Cilia and Flagella: Structure and Movement (p817-823) ------Introduction ------All Eukaryotic Cilia and Flagella Contain Bundles of Doublet Microtubules ------Ciliary and Flagellar Beating Are Produced by Controlled Sliding of Outer Doublet Microtubules ------Dynein Arms Generate the Sliding Forces in Axonemes ------Axonemal Dyneins Are Multiheaded Motor Proteins ------Conversion of Microtubule Sliding into Axonemal Bending Depends on Inner-Arm Dyneins ------Proteins Associated with Radial Spokes May Control Flagellar Beat ------Axonemal Microtubules Are Dynamic and Stable All that material on the structure, function, dynamics, and assembly of microtubules; all that stuff on cilia, flagella, axonemes, axonemal dynein, etc.; and yet nothing about actin (at least not in relation to anything of relevance. There were several very brief mentions of actin, such as in one of the introductions where microfilaments, which are made of actin, were briefly contrasted to microtubules, which are not. But the few off-hand mentions were completely irrelevant to the matter at hand: nothing that would rescue Miller). Therefore I feel quite confident in proclaiming Miller to be wrong: it is quite clear that actin is in fact not a major component of cilia. Chalk up another biological boo-boo for Miller.
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: That's more than one...which of those would you call the function of the ossicles? Apparently everyone is focussing on force transmission and not amplification since the claims that I have seen here involve deafness and not a mere reduction in hearing. So do we all agree that the function of the ossicles is the transmission of force from the tympanic membrane to the oval window?
quote: Wouldn't that make the overall hearing system an integrated system of systems? Note the Behe explicitly rejects such as being IC.
quote: No. Accessory parts can be added to an IC system and in such a case, it would not be the whole system that would be IC, but just the IC core.
quote: Does everyone agree that it is the entire hearing system - and not jsut the ossicles - that is the system under consideration? Since there' still some basics to clear up, I'll stop here.
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: But by switching to gross anatomy you are demoting your counter down to an argument from analogy.
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: Behe does not ignore the possibility of co-option: he considers it and rejects it. From my personal notes... DNAunion: From my many discussions of ID on the net, I knew that it was page 39 where Behe defines IC so that was a good place to start my search for examples of his mentioning the idea of exaptation. I needed to only skim a couple dozen pages to find a couple of examples. This first one is long — most of it is not pertinent to the point, but some may find the context as interesting as the few sentences that support my position.
quote: quote: quote: quote: quote: quote:
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
Thanks Mammuthusthat’s one reason I continue to post at these kinds of forumsI’m always learning something new!
However, I don’t think these quotes you provided totally clear Miller (or counter me): his claim, made in the context of countering Behe, was that actin was a MAJOR COMPONENT of cilia (which I stressed twice).
quote: Note the CONTEXT the statements were made in. Miller is acting as if actin were one of the major components of the cilium that Behe listed, but it is not. Now, look at the first sentence of your first quote
quote: Since ciliary motion is understood well enough without having to reference actin, and, the function of actin is totally unknown here, then actin shouldn’t be considered a major component of the cilium in the current context. Furthermore, your quote states
quote: Only 6 out of 7. So according to the authors’ statement, 1 out of 7 didn’t require actin to function, so actin is not a required part of a cilium. If it’s not a required part, it isn’t a major component in the present context. As far as the second quote you posted, it basically boils down to
quote: That’s it: this novel form of actin was present in flagella. It doesn’t state anything about it’s being a major component of the flagellum. Finally, I should point out that Behe mentions in his book that there are something like 40 different proteins associated with cilia/flagella, even though he — like the college cell biology texts I referenced — only mention several (which is why I qualified my statements several times — I realized that actin could be one of the other 30+ proteins: the question was, was actin a MAJOR COMPONENT of the cilium in the context of countering Behe...it appears the answer is still no).
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: Well now we have disagreement among the anti-Behe crowd. NosyNed says the system under consideration is the whole hearing system, but you are limiting it to just the middle ear ossicles. Again, before any claims about what is and isn't IC can be made and supported/rejected we must agree on what the system is. Only makes sense, doesn't it?
quote: Behe does rule out macroscopic biological systems from being IC.
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: No. What is being CLAIMED is that a system which SUPPOSEDLY meets Behe's definition of IC can and did evolve.
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: quote: No, it hasn't been. There's more to demonstrating that a system is IC according to Behe than just identifying the system (which still hasn't been nailed down by the anti-Behe crowd) and identifying its function (which also has not been nailed down - even you listed multiple functions for the ossicles). [This message has been edited by DNAunion, 03-09-2004]
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: But you also said:
quote: So what exactly are you claiming to be the function of the middle ear?
|
|||||||||||||||||||||||||||
DNAunion Inactive Member |
quote: quote: No, it doesn't refute Behe unless you can show that the system is actually IC according to Behe. Your simply stating over and over that it's IC doesn't make it IC.
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024