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Author
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Topic: Using cases of non-maximal entropy production rates as a way to detect design
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Jurie
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Member # 716
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posted 04. March 2004 06:50
Using cases of non-maximal entropy production rates as a way to detect design
While thinking of a way of defining Life, it occurred to me that the processes of life are quite unlike processes we might find in abiotic nature. The modern way of looking at the Second Law of Thermodynamics is that the world is active: Not only will entropy increase, but systems will settle in that state in which the rate of entropy production is maximised. In the case of complex systems far from equilibrium, this can result in the increase of order in the system, if this speeds up the rate of entropy production. Out of all possible paths along which entropy can increase, non-life processes follow those paths that maximise the rate of entropy production.
For example, in the Benard cell experiment, a liquid in a flat vessel is heated from below. The heat causes the liquid to enter into a random motion of convection. If the temperature difference between the bottom of the vessel and the surface of the liquid is high enough, the liquid settles into the Benard cell configuration. In this configuration, a number of adjacent convection rolls (Benard cells) form, increasing the order in the liquid, which speeds up the conduction of heat through the liquid. The result is that the temperature differential between the bottom of the vessel and the top of the fluid is reduced. This increase in the rate of heat conduction through the liquid has the consequence that overall entropy increases at a faster rate than before, or put differently, that the rate of entropy production is maximised.
This maximisation of the rate of entropy production is the cause of the spontaneous appearance of order in complex systems. It is also thought to have played a major role in abiogenesis.
The thrust of this post is that while complex systems can give rise to order under certain conditions, this always has the result that the rate of entropy production is maximised. This is different from the processes that we encounter in life. Processes in life also ultimately increase overall entropy, but manage to avoid this maximal rate of entropy production path in ways that are strongly reminiscent of ID.
Take for example ATP synthase. Its action is rather like a battery-driven electric motor that is doing useful work like pumping water into a high storage tank. In the motor, electric charge (electrons) flows from a negative to a positive potential through the motor coil. The magnetic field in the motor resists the flow of charge, setting up a torque in the rotor, which can be used to do useful work such as pumping water. If we disconnect the motor's axle from the pump, the rotor is disconnected from the load (the pump); the motor would spin at the maximum rate, producing only heat in the process while draining the battery.
In ATP synthase, charge (protons) flows from a positive to a negative potential, through a turbine structure (rotor) of the molecular motor. The molecular motor is mounted in a membrane that keeps the proton potentials separated; protons can move to the low potential side of the membrane via the turbine, but the turbine resists the flow of protons in such a way that a torque is set up in the rotor, causing it to turn. The rotor is connected to an excentric spindle (the gamma spindle) that activates the protein structure which does the work of binding ADP with Pi. If we remove the gamma spindle, the rotor is disconnected from the load (the ATP-fabricating protein structure); the rotor would spin rapidly while the proton potentials will simply equalise, draining away the potential proton energy and producing heat in the process. The machine fabricates three ATP molecules for each full revolution.
This is a good example of a process that takes one form of energy (proton potential) and converts it into another useful low-entropy form (ATP). The crucial point about this process, it is clearly not in the business of maximising the rate of entropy production.
Another analogy of ATP synthase is a hydro-electric plant: Water falls a certain distance, turning the turbines of the generators to generate electricity, a free (i.e low-entropy) form of energy. The waterfall/plant system is not producing entropy at the maximal rate. The maximal rate path would simply be for the water's kinetic energy to be dissipated into low-entropy heat as the water strikes the bottom of the fall in the absence of a hydro-electric plant. The intelligent design perspective is this: We are not surprised to find a waterfall; it is an expected consequence of water flowing to lower places. However, if we find a hydro-electric generator installed in a waterfall, it is unexpected - clearly it was designed to be there. The same with ATP synthase - it is one thing to note a proton potential in the mitochondria, but a different thing altogether that we find an electric motor mounted in the equalising stream of protons such that their potential energy is harnessed. Not only that, we also find processes that recharge the "proton battery". (From this perspective, this cycle is irreducibly complex.)
If we consider the principle of maximal entropy production, it is striking that this principle tells us that non-living nature is wasteful. Not only is she wasteful; abiotic nature wastes as much as possible, as fast as possible. In contrast, life is conservative.
Seeing the contrast between the two, that life manages to avoid this wasteful trend in order to squeeze maximal profit out of the available energy, I propose that this fact can be used to detect Intelligent Design. If the Laws of Thermodynamics dictate that all abiotic natural processes are maximally wasteful, then the effiency of living processes could not have arisen from those, not even in a step-by-step way, since this directly contravenes the principle of maximal entropy production. The presence of such processes therefore would indicate Intelligent Design.
For example, Rex Kerr wrote
quote:
But this is exactly what the Krebs Cycle does. It maximizes entropy locally--it just so happens that in so doing it converts sugar into ATP (quite efficiently, I might add).
Ignoring for a moment the self-contradiction in that statement, I think that last paranthetic comment is a dead give-away.
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Vob-1500
unregistered
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posted 07. March 2004 11:14
Vinicius,
Please refrain from knee-jerk reactions, and one-sentence replies. Both tend to drag down the quality of discussion we encourage here at Brainstorms.
Your post has been deleted, but feel free to try again with something substantial to say that is on-topic (trying to tie the discussion into "proving God" is not on-topic).
the friendly
Moderator
[ 07. March 2004, 14:04: Message edited by: Moderator ]
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Doubting Thomas
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Member # 1214
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posted 19. March 2004 15:22
ATP synthase evolved from simpler modules:
quote:
Biochem. J. (1988) 254 (109–122)
DNA sequence of a gene cluster coding for subunits of the F0 membrane sector of ATP synthase in Rhodospirillum rubrum. Support for modular evolution of the F1 and F0 sectors.
Falk G, Walker JE
Department of Biochemistry, Arrhenius Laboratory, University of Stockholm, Sweden.
A region was cloned from the genome of the purple non-sulphur photobacterium Rhodospirillum rubrum that contains genes coding for the membrane protein subunits of the F0 sector of ATP synthase. The clone was identified by hybridization with a synthetic oligonucleotide designed on the basis of the known protein sequence of the dicyclohexylcarbodi-imide-reactive proteolipid, or subunit c. The complete nucleotide sequence of 4240 bp of this region was determined. It is separate from an operon described previously that encodes the five subunits of the extrinsic membrane sector of the enzyme, F1-ATPase. It contains a cluster of structural genes encoding homologues of all three membrane subunits a, b and c of the Escherichia coli ATP synthase. The order of the genes in Rsp. rubrum is a-c-b'-b where b and b' are homologues. A similar gene arrangement for F0 subunits has been found in two cyanobacteria, Synechococcus 6301 and Synechococcus 6716. This suggests that the ATP synthase complexes of all these photosynthetic bacteria contain nine different polypeptides rather than eight found in the E. coli enzyme; the chloroplast ATP synthase complex is probably similar to the photosynthetic bacterial enzymes in this respect. The Rsp. rubrum b subunit is modified after translation. As shown by N-terminal sequencing of the protein, the first seven amino acid residues are removed before or during assembly of the ATP synthase complex. The subunit-a gene is preceded by a gene coding for a small hydrophobic protein, as has been observed previously in the atp operons in E. coli, bacterium PS3 and cyanobacteria. A number of features suggest that the Rsp. rubrum cluster of F0 genes is an operon. On its 5' side are found sequences resembling the -10 (Pribnow) and -35 boxes of E. coli promoters, and the gene cluster is followed by a sequence potentially able to form a stable stem-loop structure, suggesting that it acts as a rho-independent transcription terminator. These features and the small intergenic non-coding sequences suggest that the genes are cotranscribed, and so the name atp2 is proposed for this second operon coding for ATP synthase subunits in Rsp. rubrum. The finding that genes for the F0 and F1 sectors of the enzyme are in separate clusters supports the view that these represent evolutionary modules.
In addition, the alpha and beta
subunits in the catalytic F1 domain show significant sequence homology and likely evolved from a primitive ancient ATPase prior to the divergence of the Archaea, Eubacteria and Eucharyota via gene duplication.
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David L. Hagen
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Member # 323
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posted 19. March 2004 23:58
Re: None's post on ATP:
Now that is remarkable!
It provides more evidence for the irreducible complexity of ATP. See the extensive detail summarized by Jerry Bergman, Ph.D., in "ATP: The Perfect Energy Currency for the Cell"
http://www.trueorigin.org/atp.asp
(or see the Google cached version.)
Aside from the presupposition of evolution, why could not this same evidence be interpreted as efficient use of common design principles of using similar components in different applications with a few modifications to suite?
I see a remarkable amount of handwaving. Could we please see the detailed step by step specification of "small incremental changes" as to how the ATP synthase came to be formed without using the resultant ATP? Similarly, how was the ATP synthase formed incrementally without also using the cell membrane around the operation that keeps the system anaerobic and channels the protons? etc.
Back to the point of Jurie's proposition that non-maximal entropy evidences life: the hydropower plant requires both a turbine and penstock. So ATP requires the ATP synthase and the membrane properly configured to channel the protons through the ATP synthase.
The crux of Jurie's proposition is the difference in dynamic processes as to whether they maximize entropy or specifically demonstrate non-maximal entropy formation. The degree to which the rate of entropy is not maximized (relative to the uncertainty in measuring the rate), could be used as a measure of the probability of intelligent design vs natural processes.
Stating Jurie's thesis as a negative proposition:
*** Natural processes in a closed system cannot convert energy at less than the maximal rate of entropy production. ***
To be more precise we could add Dembsky's Universal Complexity Bound of 10^150. i.e., the probability of 3000 nucleotides assembling to form ATP synthase, (plus all the associated essential processes etc.) in the right order by random chance just might be a bit bigger than that! (presuming that the length of a-c-b is about 3/4 of a-c-b'-b).
The task for macroevolution is thus to show a detailed step by step sequence by which natural processes starting just with elementary chemicals in a closed system can use small incremental changes to form a "living" or self replicating system which converts energy at less than the maximal rate of entropy conversion. Furthermore, this must be done without "natural selection", since until a self-replicating system is formed, how can there be any "natural selection"?
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David L. Hagen
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posted 20. March 2004 00:01
PS This last post refers to Doubting Thomas's post (which first showed up as from "None") and to Jurie's.
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Doubting Thomas
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posted 20. March 2004 18:34
The point I'm trying to make about these 'molecular machines' is that they are millions of years of evolution removed from the original first state of life. The products that we see and that IDists admire so much are themselves the result of uncounted generations of mutation and selection.
The FoF1-ATP synthase is a perfect example. As I have posted above, primitive microbes exist where the genes for the Fo and F1 domains exist separately. This was the original, primordial state: Fo was a proton-translocating membrane pore and the simpler precursor to F1 was a simple ATPase, hydrolyzing excess ATP formed from the TCA cycle. Through gene duplication, gene fusion and evolution and the selective pressure for more ATP production, the Fo and F1 units became separate domains in a single enzyme that converts proton flux into ATP: the FoF1-ATP synthase so admired by IDists today.
But let's look deeper. A little detergent and the F1 subunits can be easily separated fronm the Fo pores. In fact, F1 domains are water soluble, unlike the membrane-encased Fo domains. Combine them and the complete enzyme reconstitutes itself. Now, let's look at the genetics which underly the construction of the protein subunits that make up the enzyme. It's interesting to note that in the nearly universal organization of the unc operon, there are two domains: the Fo domain comes first and the F1 domain comes immediately after. Guess what? The transcription of the unc operon only proceeds to the F1 subsunits after the Fo domain pores have been completed. The F1 domains self-assemble and pop into the Fo domains. If this weren't the case, and F1 domains were made first, they would have no Fo domains to stick into and would just diffuse uselessly into the aqueous cyctoplasm.
IDists are making a big mistake by assuming that the things we see in living things today are either designed or not because they little resemble the fundamental proteins and protein assemblies that they evolved from. It's the same with the bacterial flagellum: it's the product of long evolution and the parsimonious combination of several disparate cellular functions, not simply a wonderful mechanism that could only come into existence via 'design.'
[ 20. March 2004, 18:52: Message edited by: Doubting Thomas ]
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Jurie
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posted 22. March 2004 21:28
Actually, I said that ATP synthase PLUS the electron transport proton pump is irreducibly complex: It is pointless to pump protons from the matrix to the inter-membrane space if nothing further happens with the protons, but the point is they are needed there to generate the proton gradient that is used by ATP synthase. And without a proton gradient, ATP synthase is useless. So how could this system arise step-by-step? The one without the other is useless, so could not be naturally selected.
However, that was not the point of my argument in the first place, I merely mentioned this in passing.
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Jurie
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posted 22. March 2004 21:52
quote:
Guess what? The transcription of the unc operon only proceeds to the F1 subsunits after the Fo domain pores have been completed. The F1 domains self-assemble and pop into the Fo domains. If this weren't the case, and F1 domains were made first, they would have no Fo domains to stick into and would just diffuse uselessly into the aqueous cyctoplasm.
Nothing in your argument clinches it one or the other way - it is as easy to argue that this sequence is the result of ingenuity. Darwinists are making a big mistake by assuming that the things we see in living things today are evolved just because similar building blocks are used elsewhere.
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Doubting Thomas
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posted 29. March 2004 20:04
Jurie wrote:
quote:
quote:
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Guess what? The transcription of the unc operon only proceeds to the F1 subsunits after the Fo domain pores have been completed. The F1 domains self-assemble and pop into the Fo domains. If this weren't the case, and F1 domains were made first, they would have no Fo domains to stick into and would just diffuse uselessly into the aqueous cyctoplasm.
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Nothing in your argument clinches it one or the other way - it is as easy to argue that this sequence is the result of ingenuity. Darwinists are making a big mistake by assuming that the things we see in living things today are evolved just because similar building blocks are used elsewhere.
Quite to the contrary: if the formation of the '1' and 'o' domains were not universally linked in the temporal sequence F1>Fo, there would be no life. How can something that's both understandable, universal and absolutely vital be termed 'ingenuity'? How does 'ingenuity' get into this?
Please define what you mean by quote:
ingenuity
in biological terms? I've never run across it before.
You could always invoke design without justification, but the fact that all living things depend on this same mechanism calls for a common ancestor and evolutionary descent.
DT
[ 29. March 2004, 22:30: Message edited by: Doubting Thomas ]
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schwab
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posted 01. April 2004 18:12
I´m a little it puzzled of the way entropy is treated here. My reply may sound a bit superstitious, but I think it is worth to mention anyway:
Entropy is NOT the CAUSE of anything happening! It is a purely statistic feature! Entropy is a CONSEQUENCE of the activity of a system. We say, that entropy tends to increase in a system, but it just means, that the system will sooner or later occupy one of the most propable states (which is a rather obvious thing). But the most propable states are not easy to determine. It is not always a state we consider to be chaotic, it may well be a very ordered one. Entropy dynamics depend on the overall conditions in the system, i.e. the ways energy can be distributed among the different degrees of freedom. I cannot figure out how the way entropy dynamics are in living and non-living systems may tell us whether the system is made by design or by chance.
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