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"A Mathematician's View of Evolution"

brodski said:
This interpretation of the second law of thermodynamics, if accurate, would not only make evolution impossible, it would make all life impossible, the full grown plant is more complex than the seed.
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That particular interpretation of TSLOTD is a purely supernatural veiw of physics. The claim IDC proponents make is that there is an exception to TSLOTD where there exists a program to "direct growth." That exception did not appear in any chemistry or physics textbook I have ever read and I think it may exist only in the Interwebs. The initial observations that led to TSLOTD were that heat would never move from a colder body to a warmer one in a closed system. It can be expressed mathematically, but was not derived that way. However, until energy being spontaneously created or moving from a colder source to a warmer has been observed in such a way that it cannot be passed off as a statistical anomaly TSLOTD stands as one of the fundamental laws of conservation of energy. That said, TSLOTD has NOTHING to do with increasing complexity or decreasing complexity. Think about what is happening in our sun, hydrogen is technically less complex that helium ... If your concept of God is the guy making sure that hydrogen atoms get close enough to each other to take advantage of the Strong Nuclear Force and synthesize in to helium then, I have to wonder what would motivate you to get out of bed on Sunday morning to go to church. There is a mathematical harmony which underlies the universe. There are laws of electromagnetism, gravity and quantum mechanics that the authors didn't bother to take into account in denouncing life as improbable to have been derived by natural phenomenon. If one were to only count the number of particle combinations, forget about protein, water would be impossible to form. I would wager that if one were to take all of the physical laws into account as they traced our history from particles to people, that, they would find that not only is conscious life probable, it is actually inevitable.
 
I think that the objection is actually backwards. If we're talking about entropy, the SUN isn't the answer to how entropy can decrease, SPACE is. Space is so incredibly cold, relative to the Earth, that heat can dissipate into it, reducing the entropy of the Earth. Now, Sewell talks of order being the "opposite" of entropy, which isn't quite accurate. The closest thing to what he's talking about would probably be Gibbs free energy, and that is increased by the radiation from the sun. But there's no scientific meaning to "intelligent" uses of Gibbs free energy, and "unintelligent" uses.

Really, this is just a bunch of flim-flam. He says that evolution is unlikely, TSLOTD prohibits unlikely events, so TSLOTD prohibits evolution. Well, TSLOTD doesn't probihibit "unlikely events" in general (that's hardly a scientific term), it prohibits a particular class. So even is he could prove that evolution is unlikely, TSLOTD would not be necessary (Since he would have already disproved evolution) or sufficient (because TSOLTD doesn't say anything about unlikely events in general). TSOLTD doesn't have anything to do with it, and its only role is for him to attach a veneer of scientific validity.
 
Art Vandelay said:
I think that the objection is actually backwards. If we're talking about entropy, the SUN isn't the answer to how entropy can decrease, SPACE is. Space is so incredibly cold, relative to the Earth, that heat can dissipate into it, reducing the entropy of the Earth. Now, Sewell talks of order being the "opposite" of entropy, which isn't quite accurate. The closest thing to what he's talking about would probably be Gibbs free energy, and that is increased by the radiation from the sun. But there's no scientific meaning to "intelligent" uses of Gibbs free energy, and "unintelligent" uses.
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If you take the earth as one whole system, then you are fully right. However, I'd make it a little more exact and specifiy
...the SUN isn't the answer to how entropy of the earth can decrease, SPACE is.
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This would be more correct. The trick is that since the surrounding universe is so cold, it's entropy increase is drastically greater than what entropy gain the earth has by giving up that heat.(dS=dQ/T) As such, we do not violate TSLOTD.

As to your claim of the sun providing increases in Gibbs free energy, that is also equally true. But I do not know if it'd be right to use the earth as the system when we consider evolution. For evolution, we need to really consider the system as being that of the organism itself and all surroundings of the organism as the area of increased entropy. For this reason, I'd consider the effects of the sun's energy as being several steps removed...at least until photosynthesis took hold.
 
joobz said:
As to your claim of the sun providing increases in Gibbs free energy, that is also equally true. But I do not know if it'd be right to use the earth as the system when we consider evolution. For evolution, we need to really consider the system as being that of the organism itself and all surroundings of the organism as the area of increased entropy. For this reason, I'd consider the effects of the sun's energy as being several steps removed...at least until photosynthesis took hold.
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I agree. The scale is important when considering evolution, and the Sun-to-Space scale is far too large. Even when photosynthesis is taken into account that's a single, very simple link to the Sun and no link at all to Space.

On a more appropriate scale, a compost-bin contains a concentration of life and the rate of entropy-increase is far greater than if the compostables were simply left on the ground. Life rides on the flow of entropy, carefully creating back-eddies that accelerate the overall flow. So to speak.
 
Taffer said:
Something occurs to me. One part of the immune response in plants is a phenomenon called RNA interference, or RNAi. Basically, often plants contain a gene which is shared with a particular virus, and the RNA produced by this gene disactivates the virus through RNAi (oversimplification, I know, shush). Plants can also gain resistance to a virus which it was not before, by the incorperation of a viral gene. This gene was not included in the seed, but increases the complexity of the organism, and is totally independant of it.
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Viruses are usually left out of mathematical treatments of evolution, and yet they are engaged at the very heart of matters, DNA and basic cellular regulation. The influence of viruses on evolution is unquantifiable, but it has to be very significant. They can affect the germ-line, and can accidentally carry genes between individuals or even species. Science knows little about their origins - presumably renegades from cellular DNA/RNA - and has only recently cracked some of their behaviours. There might well still be types of virus undiscovered.
 
joobz said:
As to your claim of the sun providing increases in Gibbs free energy, that is also equally true. But I do not know if it'd be right to use the earth as the system when we consider evolution. For evolution, we need to really consider the system as being that of the organism itself and all surroundings of the organism as the area of increased entropy. For this reason, I'd consider the effects of the sun's energy as being several steps removed...at least until photosynthesis took hold.
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Well, it's the whole system that's being considered in evolution. After all, evolution doesn't act on individuals, it acts on species. And this whole thing is mostly a red herring, anyway, because, for the most part, organisms don't decrease entropy, even locally. He's using the "etropy = disorder" equivocation.
 
Art Vandelay said:
Well, it's the whole system that's being considered in evolution. After all, evolution doesn't act on individuals, it acts on species.
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true, but it again isn't the entire planet. So, this would be one of the situations were the system boundries would have clearly distinct physical boundries. If you could draw a box arround all of living species and exclude the remainder, then this would be the most logical method. However, these are closed systems, since there is a mass flow in and out of all living species as well. But you can still do entropy caculations on open systems, you just have to perform energy/mass balances on the influx and efflux from the total "evolutionary system."

Art Vandelay said:
And this whole thing is mostly a red herring, anyway, because, for the most part, organisms don't decrease entropy, even locally. He's using the "etropy = disorder" equivocation.
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Actually, organisms do decrease their own entropy. consider the compartmentalization of organelles within a cell. The concentration variances between organelles and the cytoplasm have a much lower entropy than if you just blend all of these compartments together. But in order to acheive this level of ogranization, they just produce more entropy in thier surroundings.


As for the entropy=disorder equivocation, this isn't wrong. At the very least, it is the easiest way to grasp what entropy is. Again, the main mistake made with entropy is defining what the system is in relationship to the surroundings. This is why the boundries you use to define the system is so critical in properly evaluating the system.
 
joobz said:
Actually, organisms do decrease their own entropy. consider the compartmentalization of organelles within a cell. The concentration variances between organelles and the cytoplasm have a much lower entropy than if you just blend all of these compartments together. But in order to acheive this level of ogranization, they just produce more entropy in thier surroundings.
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But first they produce more entropy within themselves.

As for the entropy=disorder equivocation, this isn't wrong.
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"Entropy is a type of disorder" isn't wrong. But "'Entropy' and 'disorder' can be used interchangeably" is.
 
Art Vandelay said:
But first they produce more entropy within themselves.
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can you explain this?
I fully disagree that a system has to produce more entropy within before it exchanges energy with the surroundings.

Art Vandelay said:
"Entropy is a type of disorder" isn't wrong. But "'Entropy' and 'disorder' can be used interchangeably" is.
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I'd say that entropy is a specific subclass of disorder. It doesn't apply to social disorder or economic disorder. I generally don't accept it's use in these settings. However, for any fundemental energy exchange/state change system, entropy=disorder is acceptable by me.
 
joobz said:
can you explain this?
I fully disagree that a system has to produce more entropy within before it exchanges energy with the surroundings.
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Well, in the long run, it does. To exchange energy, it has to be at a higher termperature (or a lower one, but in the long run, a lower temperature isn't possible to achieve). To be at a hiher temperature, it has to turn energy into heat, increasing entropy.

I also don't agree that concentration differentials, in themselves consitute lower entropy. Certain types, yes, but not in general.
 
Art Vandelay said:
To be at a hiher temperature, it has to turn energy into heat, increasing entropy.
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Temperature can change without a change in entropy and viceversa. You can increase the temperature without exchanging heat (adiabatic process). You can also exchange work with the surroundings. Or am I misunderstanding what you are trying to say?
 
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I said that I was talking about the long term. An organism can't just keep an adiabatic process going indefinitely. Eventually, it willhave to be reversed.
 
Art Vandelay said:
Well, in the long run, it does. To exchange energy, it has to be at a higher termperature (or a lower one, but in the long run, a lower temperature isn't possible to achieve). To be at a hiher temperature, it has to turn energy into heat, increasing entropy.
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I don't know what you mean by the long run. If we consider systems organisms that maintain a higher internal temperature, than the release of heat intor thier surroundings will result in a much greater entropy increase than any change internally. (ds=dq/T) Lower T equal greater entropy increase at equivilent heat flows.

But again, entropy isn't just heat. It is also densities, concentrations, votage potentials.. Any point that has a potential beyond equilibrium has a lower entropy than the equilibirum condition.

Art Vandelay said:
I also don't agree that concentration differentials, in themselves consitute lower entropy. Certain types, yes, but not in general.
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again, please explain. If you look at statistical mechanics of the system; two domains with different concentrations. The domain with higher concentration will have much lower number of positional configurations, thereby a lower entropy. As you tend to equilibrium, the potential number of configurational positions increases, thereby increasing entopy.

thanks
Tom
 
Art Vandelay said:
But first they produce more entropy within themselves.
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So they do, which is the point. Just as a refrigerator puts out more heat than it extracts from the objects it cools, a cell uses more energy than it stores in its products. When a sugar molecule's energy is used to create ATP from ADP some energy is lost as heat. A sugar molecule left to its own devices would eventually break down releasing all of it's energy as heat, but the rate is vastly different to its fate inside a cell. That's accelerated entropy-flow.

When enzymes use the ATP-ADP energy to build something they again lose some of it as heat. ATP would hang around a lot longer left to its own devices, but the enzymes hurry the process along. Accelerated entropy-flow.

You can't push things against the entropy flow without increasing the rate of entropy-flow. That doesn't mean you can't push things against the entropy-flow - otherwise no refrigeration. (I think that's logical.) Any engine does the same thing - coal takes an age to oxidise left to itself, but in a hot firebox beneath a boiler it's gone in an instant (relatively speaking). The firebox limits the coal's "number of positional configurations" and the boiler leaves the water it contains few options as well. Add some further constraints involving pistons and levers and such and you have an engine that can reduce entropy where you want it reduced. In the process it greatly increases the overall rate of entropy-flow - coal to CO2 and ashes.

A cell is no different from an engine, and nor is an enzyme-driven reaction within a cell.
 
joobz said:
I don't know what you mean by the long run. If we consider systems organisms that maintain a higher internal temperature, than the release of heat intor thier surroundings will result in a much greater entropy increase than any change internally. (ds=dq/T) Lower T equal greater entropy increase at equivilent heat flows.
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I'm saying that in the long run, very little of the entropy decrease is permanent. The entropy decrease of the organism is balanced by its increase through food consumption.

If you look at statistical mechanics of the system; two domains with different concentrations. The domain with higher concentration will have much lower number of positional configurations, thereby a lower entropy.
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That's the statistical mechanics definition of entropy, not the thermodynamic one.
 
Art Vandelay said:
I'm saying that in the long run, very little of the entropy decrease is permanent. The entropy decrease of the organism is balanced by its increase through food consumption.
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Well, no localized entropy decrease is permanent. that's the point. When the organism dies, entropy will increase. But I think again the confusion here is how are you setting your boundries.
as in the refridgerator example, You have the ice box that is permanently lower entropy than the surroundings due to the kickout of heat. So even at instantaneous moments in time, there is more entropy being generated than what is being reduced in the icebox domain.

I do not think we are really that far from each other in terms of intent. Again, the primary contention is how we are defining the system boundries. The most accurate way would be consider it as an open system. If we include the influx of food and gas and the efflux of waste products, there is an entropy change in these as well. We can consider that we do not just lower the entropy of the system through heat reduction, but by also eliminating material with a higher entropy than what is coming into the system. The food has a lower entropy (increased number of bonds give lower entropy).
As we reduce these bonds and extract energy for the system, we not only produce some heat due to inefficiency but also increase entropy by creating smaller molecules. This is what I think CapelDodger was getting at. That the exergy generated by consumption of food goes into reducing the organisms internal entropy by creating large polymeric chains, localized domains of concentrations, establishing potentials across membranes...But since the waste produces of metabolism are eliminated from the system, this entropy increase can be considered external to the organism.

No one here is claiming that life goes against thermodynamics. On the contrary, it is a perpetual generation of entropy by maintaining the higher degree of order within the organism that makes it completely acceptable in a thermodynamic setting.


Art Vandelay said:
T[hat's the statistical mechanics definition of entropy, not the thermodynamic one.
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This distinction is artificial. There is no disagreement between the 4 postulates and the statistical mechanics definition. While ChemE texts tend to ignore it, MaterialsEng thermo texts always include a statistical definition. Mainly because the classic definition is incomplete and doesn't describe as well entropy changes in multiphasic systems. I think you cannot ignore this when considering the highly structured systems of an organism.
 
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