Entropy and evolution

[Helen]

Originally posted by The Galatian:
So, what process, required for evolution, is prohibited by entropy?

A specific physical process, with your evidence that it cannot happen.

Let's try photosynthesis. This is a massive increase in complexity achieved by plants which could not have happened all at once but would require increases in complexity to be sustained and progressive.

I submit that entropy, as a generalized trend, would prevent this from happening. The tendency towards a breakdown in component parts before they were all functioning together and being replaced by the cell as needed would prevent photosynthesis from forming step by step in a cell.

 

[Paul of Eugene]

Originally posted by Helen:
</font><blockquote>quote:</font><hr />Originally posted by The Galatian:
So, what process, required for evolution, is prohibited by entropy?

A specific physical process, with your evidence that it cannot happen.

Let's try photosynthesis. This is a massive increase in complexity achieved by plants which could not have happened all at once but would require increases in complexity to be sustained and progressive.

I submit that entropy, as a generalized trend, would prevent this from happening. The tendency towards a breakdown in component parts before they were all functioning together and being replaced by the cell as needed would prevent photosynthesis from forming step by step in a cell. </font>[/QUOTE]Helen, you answered the wrong question. The question was not "can you cite an example of irreducible complexity" but "What fundamental process in evolution theory is prohibited by entropy". Your choices are between arrival of new generations, mutations, natural selection, things that are in the theory along that line.

No doubt that's an interesting debate in its own right, but . . . it should be in another thread.

 

[The Galatian]

It's not surprising that Helen can't find anything. No one ever has.

It's a dead argument.

I'll start another thread on the evolution of photosynthesis in modern plants. It's kinda interesting.

 

[mdkluge]

Helen wrote:

Peter, Mark, let me know when either one of you have read the book, OK?

Let me know, Helen, when you think you understand thermodynamics at the level of an undergraduate junior or senior in either physics or chemistry.

Why should I read a popular book on thermodynamics? At issue is how thermodynamics is understood by scientists, and what may be infered from that understanding. It doesn't matter what some popularizer might have said.

Anyhow you have done a sufficiently good job of quoting Atkins that someone competent in thermodynamics can explain for you the peculiarities of his language, what he means by "natural" processes, and how what you have quoted pertains to very standard second law of thermodynamics.

Until then, I have not only read it, I have it here, have read several parts of it several times (and all of it once) and really am not too bad at reading comprehension.

Your "not too bad" reading comprehension refers to your reading averaged over what you read. That says nothing about your comprehension of this particular piece of reading. That is to be judged by the quality of remarks you make on it.

So far you've failed utterly. Atkins the popularizer isn't laying out a grander scheme of entropy than is found in the professional literature. That you think so based upon your reading of him should make it clear to even you that you have not understood what you have read.

 

[Peter101]

Dr. Ken Dill uses a considerably different argument than is usually used, to refute the common creationist claim about thermodynamics. Here is what he said:

"The Second Law has little to do with the chemical origins of life. The reason is that the sort of order and disorder that is described by the thermal entropy is not related to the sort of "complexity" that distinguishes living from nonliving systems."

Helen, what he means in the above is that entropy being a function of heat, cannot measure the type of complexity that is involved in evolution. In other words, the attempt to use entropy in this debate is totally wrong to start with, regardless of the precise wording of the 2nd law of thermodynamics. It is true that IF entropy were a measure of complexity related to evolution, then because living systems are not closed systems, then entropy can decrease without violating the second law. This is the most common scientific objection to the creationist argument. But Dill is objecting on a more fundamental level. He is saying that because of the extreme simplicity of entropy, it cannot be a measure of any supposed complexity related to evolution. He says this because entropy is only a function of heat and temperature and has no relation at all to the supposed change in complexity of an evolving species. He has a good point. In order for creationists to use any argument based on entropy, you must first show that entropy is a measure of the type of complexity involved in evolution. I think that is impossible to demonstrate.

 

[mdkluge]

Yes, Peter101, but I was trying to stick to discussion of evolution of life rather than the origin of life. In fact it's much easier to show how the origin of a cell is compatible with thermodynamics!

We first note that thermodynamics is concerned with end states. It isn't concerned with the path between those states. Let us then consider a system containing no living cell, but the nutrients needed for a living cell. Call this the initial state. NOw add a living cell. This adds some amount of entropy to the system, call it S1. Let the cell eat nutrients, excrete, and divide. This is all thermodynamically possible, since we observe it all the time. Now remove one of the cells from the system. This subtracts the same amount of entropy added when the original cell was introduced.

We thus have at least one path from the initial state (nutrients, but no living cell) to the final state (some nutrients eaten, some excreta, and a living cell.) There is no violation of any law of thermodynamics. Hence the final state is not thermodynbamically inaccessible from the initial state. The change in entropy between initial and final states is path-independent, so it does not matter for our thermodynamic analysis that the cell formed by means other than those we used.

 

[Peter101]

&gt;&gt;&gt;&gt;&gt;&gt;&gt;Let's try photosynthesis. This is a massive increase in complexity achieved by plants which could not have happened all at once but would require increases in complexity to be sustained and progressive.

I submit that entropy, as a generalized trend, would prevent this from happening.&lt;&lt;&lt;&lt;&lt;&lt;

Helen, if you are correct in the above, you should be able to show it mathmatically. Can you?