Is there more than one definition of natural selection?

The separation of oil and water is driven by hydrophobic interactions between the hydrocarbon molecules and the water molecules. But my question is: once the separation has occurred, do we now have an internally coherent structure?A

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Natural Selection is not Evolution-- R.A. Fisher

No. You have an internally emulsified structure, I assume, which isn't a coherent structure at all. The issue at stake here may be reversibility vs. irreversibility. Reversible processes lead to disorder per the second law; that's your oil suspension in water. Irreversible proceses, such as genetic expression, will dissipate entropy profusely, but achieve complex ("higher") order far from thermodynamic equilibrium.”HM

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No. You have an internally emulsified structure, I assume, which isn't a coherent structure at all

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Once the oil and water have separated, it is not an emulsion.A

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Natural Selection is not Evolution-- R.A. Fisher

I'm not clear about the point you are making. Can you expand on it a little?”HM

Well, I assumed when you wrote 'internally emulsified', you were referring to an emulsion. Once oil and water are separated, there is no emulsion, and therefore is not an 'internally emulsified structure'.A

If you desire to operationalize Progogine's ideas then you will need to enumerate the forces as a physicst does, rather biophysically, otherwise it seems to me that dissipation is as helpful as a ID.In a detailed paper, there is a presentation on the relative influence of gravity necessary to carry out dissipation over countervailing forces(Brownian motion etc). I suppose I could venture over the physics library at Cornell and try to find what I read a few years ago if that would really be of anyhelp to you. One would need to show that gravity promixately forms forms during development however and find such a biological case to invoke the Prigogine's ideas. This could be THEN related to survival and vital statistics.I guess it was the slime mold that many tried to think about dissipatively, visualizing cyclic AMP, pulses, but again this is thought of in the sense that Wright thought of population structure not in the absolute difference of Wright's and Fisher's positions (aka selection convergence vs networks of selection)for instance. It is well time for biologists to do better."Force" inside quotation marks gets no one any better understanding of evolutionary theory than following the differences of opinions of claims throughout the literature. It only permits a kind of metadiscussion of evolutionary theory. This is needed by an evolutionary theory that is trying to defend its former stronghold before language was related to its content. It enables the discussion to proceed to dynamics without worrying about occasionalism. I find this disucssion would be more profitable and may not cost as much if done in terms of actual physical forces than the insitutions' attached social realtions.If you presented a case of dissipation and then showed how it may function under selection and that this case requires the non-equilibrium equilibrium that you advocate thus discussing biology towards criticism of biology I would understand, otherwise I do not. My suspicion is that supposed cases of dissipation biology are simply ones where levels of selection have ruptured levels of organization but this is only my intution speaking and like assumptions making asses of me and you it requires tution if the doc is in, but not so much as would be required in your case that I mispoke about someone's body part.I can understand you without the pejorative's like ,"whatever the hell".

Allopatric, back to your question in Message 196: No. I don't think there ever was an internally coherent structure in your oil-water mixture, shaken or otherwise. This would not be a good system to study far-from-equilibrium thermodynamics. What might instead take place in your experiment, using different chemicals, is a periodic precipitation (a fluctuation) of certain salts”lead nitrate, for example”as they diffuse into an aqueous medium, such as a gel. The point here is that, initially, the system reaches a far-from-thermodynamic-equilibrium condition and internally creates order through fluctuation at the cost of higher entropy production. I suppose such a dissipative structure would involve an exothermic chemical reaction.”HM

It is possible to think of an oil-water mixture in some different physical chemical states as means to substantiate Gladyshev's view on entropy as opposed to Progogines.Seeing what chemicals you DO think about, I can only say that your veiw is more like the one that life can be made of silicon as well as carbon and that man is a machine. This view is not mine. It reminds me of Newton's discussion at the end of Optikcs, however Issac both moved on, in the discussion to life being like a gentle fermentation of the salts or Earth itself, and agreed on chemistry over "conspiring motions". The problem with the non-equilibrium view is that it will require scientists to argue OVER again, agasint vitalism because the SPACE the dissipation extends TO is not occasionally vicariated from that to which former "occult" qualites were in substance for.

Yet another Bradism. There must be some good herbs over there in Ithaca, NY.”HM

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No. I don't think there ever was an internally coherent structure in your oil-water mixture, shaken or otherwise. This would not be a good system to study far-from-equilibrium thermodynamics.

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Actually, it is very good for our purposes, as my next question will reveal: do you consider a cell membrane (which is maintained by a cell using hydrophobic interactions of hydrocarbons and water just as the equilibrium state of our oil-and-water bottle is maintained) internally coherent?And another question: in our oil-and-water example, which state has the highest entropy, mixed or separated?A Edited by Allopatrik, : Added additional question.

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Natural Selection is not Evolution-- R.A. Fisher

A, you ask: Now I am catching more of your drift. Hard question to answer, but I'd say 'yes' for this reason: The cell membrane is made of phospholipids, using hydrophobic-hydrophilic interactions to hold this bilayered structure together. The cell membrane, however, is a product of the cell's creativity far-from-thermodynamic equilibrium. In many cells it is the rough endoplasmic reticulum that assembles membranes and associated proteins. This would be where the entropy of interest shows its face, blushing profusely with its production far from thermodynamic equilibrium. It would seem that more molecular dissorder is accomplished by shaking the oil-water mixture. You apply energy to shake the mixture and your get entropy as a result. As long as you kept shaking it you would achieve maximum entropy production for that system. You could say that you are holding it far from equilibrium by the energy of your shaking. Stop that energy input to your system and it settles out as a separated bilayer in the neighborhood of thermodynamic equilibrium.BTW: I noticed over in Message 1 that the author Sanford has apparently turned a "genetic entropy" concept into a Creationist argument. I probably would, too, if I were a Creationist. But I'm not. I'm not quite ready for God when I don't even know how His biological toys work. My main interest in "genetic entropy" has to do with the imposition of a digital code on the affairs of molecular biology; it's my fascination with the "dynamics" of genes, struggling to understand what that word "dynamics" means to a state of "pure information" (Dawkins).How can pure genetic information be obedient to physical laws? Not all dissipative structures are genetically endowed. Is biological life, a frog, actually a dissipative structure? Or is it something entirely different?”HM

Is there more than one definition of natural selection?

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The cell membrane, however, is a product of the cell's creativity far-from-thermodynamic equilibrium. I

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You seem to be saying that the cell-membrane is a low-entropy entity. What makes you say that (especially after what I explain below)?

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It would seem that more molecular dissorder is accomplished by shaking the oil-water mixture. You apply energy to shake the mixture and your get entropy as a result. As long as you kept shaking it you would achieve maximum entropy production for that system. You could say that you are holding it far from equilibrium by the energy of your shaking. Stop that energy input to your system and it settles out as a separated bilayer in the neighborhood of thermodynamic equilibrium

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That isn't the case. In the mixed state, the water molecules are more constrained due to contact with the hydrocarbons, and thus have lower entropy than when they are in a pure water solution. Therefore, the hydrophobic interactions, which drive the separation, result in an overall higher entropy state when at equilibrium (separation) than when mixed. This is what we would expect under the Second Law of Thermodynamics. Adding energy outside of the system (as in the shaking) results in lower entropy.So, should we expect cell membranes, which are maintained almost solely by hydrophobic interactions, to be low-entropy entities?A

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Natural Selection is not Evolution-- R.A. Fisher

A, you ask: As compared to what? I might ask.I had better cool it it here, or AdminMod will slap a ticket on me.Back on topic: Do you think thermodynmaic entropy should be included in the concept of biological evolution? Is there a thermodynamic definition of natural sedelction? Does drift, for example, equate to entropy? It is, after all, a randomizing "force" that changes allele frequencies in a population. Is there any reason why biological evolution should obey thermodynamic laws?”HM

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Back on topic: Do you think thermodynmaic entropy should be included in the concept of biological evolution?

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No. It has little, if any relevance to the understanding of evolutionary principles.

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Is there a thermodynamic definition of natural sedelction?

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No, and for a perfectly good reason: it's irrelevant.

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Does drift, for example, equate to entropy?

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No.

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It is, after all, a randomizing "force" that changes allele frequencies in a population.

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But that is only due to the stochastic processes of meiotic segregation and the reality of finite populations. Nothing to do with thermodynamics per se.

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Is there any reason why biological evolution should obey thermodynamic laws?

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Who says it doesn't?A

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Natural Selection is not Evolution-- R.A. Fisher