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Author Topic:   Thermodynamics, Abiogenesis and Evolution
JonF
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Message 5 of 128 (99474)
04-12-2004 4:44 PM
Reply to: Message 2 by DNAunion
04-12-2004 3:34 PM


Until some prebiotically plausible mechanism for capturing and channeling the available prebiotic energy into performing useful "biological" work is found, vague appeals to "open systems" just aren't sufficient ("open system thermodynamics" are necessary, but not sufficient).

Er, you appear to have a serious misunderstanding of thermodynamics.

The second law deals with entropy, and entropy is a property; that's a technical term that means its value depends only on the current state of the system and not in any way how the system got to that state. (This is often very useful, because it means that we can calculate entropy changes between two states along any possible and equivalent path). Therefore the idea of needing to know a mechanism (for the transition between states) in order to evaluate the thermodynamic possibilities is a red herring.

What counts thermodynamically is the difference in entropy between the initial and final states, not how it got from one state to the other. I think that some people have done such calculations for some proposed scenarios, but I'm not sure. However, what I am sure of is that you can't claim that the second law of thermodynamics poses any problem for any hypothesized event until you have calculated the change in entropy and demonstrated a spontaneous decrease.

Nor can you claim that particular characteristics of a system are or are not necessary, or are or are not sufficient, until you have presented the appropriate calculations.

Of course, we are trying to figure out mechanisms for all sorts fo reasons; but we do not need to know a mechanism to evaluate what thermodynamics allows.


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 Message 2 by DNAunion, posted 04-12-2004 3:34 PM DNAunion has responded

Replies to this message:
 Message 11 by DNAunion, posted 04-13-2004 12:27 AM JonF has responded
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JonF
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Posts: 5738
Joined: 06-23-2003
Member Rating: 2.2


Message 13 of 128 (99633)
04-13-2004 8:48 AM
Reply to: Message 11 by DNAunion
04-13-2004 12:27 AM


JohnF: The second law deals with entropy, and entropy is a property; that's a technical term that means its value depends only on the current state of the system and not in any way how the system got to that state.

Yeah, so what? You’re confused. You see, I am not talking about only thermodynamics: I am talking about thermodynamics as it applies to the origin of life – more than one field of science is involved here.

It doesn't matter how many fields of science you are talking about, it doesn't matter if you are talking about thermodynamics as it applies to the origin of life or as it applies to steam power plants or as it applies to anything at all. Entropy is a property and its value depends only on the current state of the system and not in any way how the system got to that state. Until you realize and accept that your thermodynamic claims are gobbledygook.

Explaining how life could arise from nonlife requires explaining the mechanism by which a decrease in entropy - associated with the formation of biological polymers and systems of such polymers - could have plausibly occurred in a prebiotic context.

From the point of view of thermodynamics, absolutely not. If you wish to claim (as you have) that there is a thermodynamic problem with abiogenesis, the only way you can support that statement is with calculations that demonstrate an overall decrease in entropy.

Of course, from the point of view of abiogenesis research, explaining the mechanism is key ... but we're not discussing that, we're discussing your claim of a thermodynamic problem.

Simply saying sufficient energy was available because the Earth is an open system is insufficient.

Agreed, but irrelevant to your claim of a thermodynamic problem.

In the absence of calculations we don't know if there is a thermodynamic problem. As I said in my earlier message, I think such caclulations have been made for some scenarios; but the relevant item is your claim that there is a problem. Simply saying that it hasn't been proved that there is no problem is insufficient; you claimed there is a problem, support that claim.

For example, we know that the change from free monomers to polymers involves a decrease in entropy (increase in order) and is endergonic (which is why OOL researchers preactivate their monomers). And we know this without having to know exact values. So polymer formation goes in the wrong direction and is thus a nonspontaneous process. Therefore, some sort of process or mechanism must be present in order for such an uphill process to occur (for example, cells couple endergonic reactions with exergonic reactions, usually using ATP as an energy intermediate).

Agreed. However, in order to determine the thermodynamics of the situation we do not have to have the slightest idea of what that process is or was. All we have to know is the starting state of an appropriate system and the ending state of that same system. It may be convenient to calculate the changes by integrating along a process path from the initial to the final state, but it is not required to do so, and that process path can be any physically possible path; it need not be the actual path and it can be a ludicrously unrealistic path.

So relying on just vauge appeals to "open system thermodynamics" for translation is insufficient in more than one way - same goes for OOL.

True; but appeals to open system thermodynamics do demonstrate that it's plausible that there may not be a problem. However, it's still irrelevant to your claim that the second law of thermodynamics poses a problem for abiogenesis. You need to supply positive support for that claim, not just vague appeals to a supposed lack of support for other's claims.


This message is a reply to:
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Replies to this message:
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JonF
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Posts: 5738
Joined: 06-23-2003
Member Rating: 2.2


Message 17 of 128 (99690)
04-13-2004 1:29 PM
Reply to: Message 14 by DNAunion
04-13-2004 9:54 AM


Let me try an analogy ... gravity poses a problem for the origin of pyramids (analogous to how the second law poses a problem for OOL).

You have made nothing but assertions. I (and, I believe, others) understand what you are saying and don't need your analogies ... what we are asking for is evidence for your unsupported assertion that "the second law poses a problem for OOL".

Thermodynamic calculations should be part of a comprehensive theory of abiogenesis (which theory we don't have yet). Only a fool would offer a hypothesis which requires flouting the second law. But until calculations are presented nobody, including you and me, knows whether or not "the second law poses a problem for OOL".

Present your calculations or accept that you do not know whether or not "the second law poses a problem for OOL".


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JonF
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Posts: 5738
Joined: 06-23-2003
Member Rating: 2.2


Message 24 of 128 (99715)
04-13-2004 3:35 PM
Reply to: Message 21 by DNAunion
04-13-2004 2:48 PM


Tell you what, why don’t you tell us exactly what you (wrongly) think I said

I thought you said:

"The second law of thermodynamics poses no problem at all for evolution: abiogenesis is a different story."

and "... the second law poses a problem for OOL"

and "The second law of thermodynamics poses a problem for abiogenesis in a manner similar to how gravity poses a problem for pyramid builders."

The last statement is likely to be correct, but all are unsupported assertions.

It appears to me that you are claiming that we know that abiogenesis is impossible because it violates the second law. That claim is absolutely untrue; it is possible that there is no scenario of abiogenesis that violates the second law (actually, I think that this has been ruled out already, but I'll admit the possibility because I'm not sure), but we don't know that abiogenesis violates the second law.

Now, if you said that the 2LoT must be consisdered in any sufficiently advanced theory of abiogenesis I would agree. If you want to argue that thermodynamics might pose a problem for abiogenesis, I could go along with that. But you said that "the second law poses a problem for OOL", which means either that you are just blathering or you think you have a thermodynamic calculation which demonstrates that a first self-replicator arising from primordial conditions must violate the second law of thermodynamics.

I already pointed out that going from free monomers to polymers involves a decrease in entropy: the fact is there whether I provide any calculations or not. Do you need me to support that statement with quotes? I can.

I believe you could. The fact that entropy decreases in a portion of a particular system does not mean that the second law is violated. Hell, I'll even accept without proof that those studies going from monomers to polymers is relevant to all possible modes of abiogenesis. So what?

What you need to provide to support your claim is a calculation that shows that the second law of thermodyanamics prohibits a self-replicator from arising.


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JonF
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Posts: 5738
Joined: 06-23-2003
Member Rating: 2.2


Message 37 of 128 (99794)
04-13-2004 9:57 PM
Reply to: Message 34 by DNAunion
04-13-2004 9:38 PM


Do you really equate the words "problem" and "impossible"? You shouldn't - problems can be overcome: impossibilities can't. Two very different things

Ah, now I understand ... you have no point.

If abiogenesis is prohibited by the second law of thermodynamics, that's a problem that cannot be overcome.

If abiogenesis is not prohibited by the second law of thermodynamics, there is no problem.

That's all there is.


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Replies to this message:
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JonF
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Posts: 5738
Joined: 06-23-2003
Member Rating: 2.2


Message 40 of 128 (99804)
04-13-2004 10:31 PM
Reply to: Message 39 by DNAunion
04-13-2004 10:12 PM


Re: Let Confusion Reign
There is a problem that has yet to be fully solved.

Sorry, that's not a possibility. Either there's a problem that cannot be solved, or there's no problem. And you have no idea which it is.


This message is a reply to:
 Message 39 by DNAunion, posted 04-13-2004 10:12 PM DNAunion has responded

Replies to this message:
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JonF
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Posts: 5738
Joined: 06-23-2003
Member Rating: 2.2


Message 46 of 128 (99907)
04-14-2004 9:14 AM
Reply to: Message 45 by DNAunion
04-14-2004 12:35 AM


Re: Let Confusion Reign
Somehow, I'm not sure how, you're setting some kind of trap for me, aren't you?

Nope, just simple logic.

Either the 2LoT poses a problem for abbiogenesis, or it doesn't (whether or not we have the informatioin required to determine which). Clear so far?

If the 2LoT poses a problem for abiogenesis, that problem can't be solved. Therefore that problem is not a "problem that has yet to be fully solved."

If the 2LoT does not pose a problem for abiogenesis, then there is no thermodynamic problem with abiogenesis. Therefore there is no thermodynamic"problem that has yet to be fully solved."

No matter what, there is no thermodynamic "problem that has yet to be fully solved" with abiognesis. There cannot be.

Of course, there are plenty of questions and problems with abiogenesis that are not fully solved, and we don't know anywhere near what we'd like to about the thermodynamics of abiogenesis, but ...

"The second law of thermodynamics poses no problem at all for evolution: abiogenesis is a different story." is an unsupported assertion, and you have made no attempt to support it. All you've done is blather.

Where are your calculations that demonstrate that the second law of thermodynamics is a problem for abiogenesis?


This message is a reply to:
 Message 45 by DNAunion, posted 04-14-2004 12:35 AM DNAunion has responded

Replies to this message:
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JonF
Member
Posts: 5738
Joined: 06-23-2003
Member Rating: 2.2


Message 49 of 128 (99932)
04-14-2004 11:36 AM
Reply to: Message 48 by DNAunion
04-14-2004 9:52 AM


Re: Let Confusion Reign
ohnF: If the 2LoT poses a problem for abiogenesis, that problem can't be solved.

That's a flawed premise. None of your other "simple logic" matters since this premise of yours is wrong.

Indeed? You think that, if the 2LoT forbids abiogenesis, then abiogenesis can still take place?

I told you before, I don't need calculations. I have logic that shows, for example, that polymerization is an uphill process from free monomers. There's the problem. How was it solved prebiotically?

It is not necessary to know the process to evaluate the thermodnamics (although it often helps). The fact that polymerization is an uphill process does not lead to your conclusion that there's a thermodynamic problem; "uphill" processes happen spntaneously all the time. I'll tentatively accept your claim that tests have been unsuccessful; that still doen't mean that there's a thermodynamic problem.

It's a problem for abiogenesis researchers ... but it is not necessarily a thermodynamic problem, as you have claimed. The only thing that will demonstrate a thermodynamic problem is calculations.

Your logic is flawed; try writing it out as a syllogism and laugh at it.


This message is a reply to:
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Replies to this message:
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JonF
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Posts: 5738
Joined: 06-23-2003
Member Rating: 2.2


Message 54 of 128 (99972)
04-14-2004 2:06 PM
Reply to: Message 52 by DNAunion
04-14-2004 1:43 PM


Re: Let Confusion Reign
Uhm, uphill processes never happen spontaneously: in fact, uphill indicates nonspontaneous

You're right; I should have said "uphill processes happen all the time in nature".

And, until you produce evidence that the uphill processes involved in abiogenesis cannot happen in nature, you have failed to support your claim that "The second law of thermodynamics poses no problem at all for evolution: abiogenesis is a different story." It doesn't matter whether or not someone has found a process which can occur in nature; you have claimed that there is reason to believe that there is no such process.


This message is a reply to:
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Replies to this message:
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JonF
Member
Posts: 5738
Joined: 06-23-2003
Member Rating: 2.2


Message 64 of 128 (100009)
04-14-2004 4:32 PM
Reply to: Message 60 by DNAunion
04-14-2004 2:51 PM


Re: Let Confusion Reign
I have not claimed impossibility, not at all. I mentioned problems - problems are solvable; impossibilities aren't.

So, as myself and at least one other has mentioned, you have no point whatsoever. Your entire contribution to this thread has been empty rhetoric.

You continue in your dishonesty.

That's an an unwarranted insult. I have been polite, honest, and patient. I have a hypothesis as to why you stoop to such ...


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JonF
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Posts: 5738
Joined: 06-23-2003
Member Rating: 2.2


Message 72 of 128 (100457)
04-16-2004 6:38 PM
Reply to: Message 71 by rineholdr
04-16-2004 2:06 PM


Well just for the record The first living cells are far from simple! The simplist living cells far exceeds in complexity anything man can concive. They make by design a kray computer or a space shuttle seem as mear childs play

Please supply evidence for your assertions about the first self-replicator ... note that I asked for the first self-replicator, which most likely preceded the first thing we would call a cell by many milions of years.

Your "argument" sounds like nothing more than "I think they must have been complicated" to me.

Construct and make functional a simple cell. Just that simple, I mean if the random combinations of simple molecules can spontaiously evolve into life, this challage should be quit simple.

Nobody has claimed that producing a cell from "primordial soup" is simple or even possible in human time scales. Our inability to do such to date proves exactly one thing ... we can't do it now. It has no relevance to the possibilities of abiogenesis. Nor does it have any relevance to the theory of evolution.

edited to add:

I mean if the random combinations of simple molecules can spontaiously evolve into life, this challage should be quit simple.

Please provide your calculations or other evidence of how simple this should be.

[This message has been edited by JonF, 04-16-2004]


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