Is Evolution Universally Driven by Self-Perpetuating Processes?

[baywax]

Well, although the etymological origin of the word evolution does come from the Latin 'unrolling' the meaning of the English word was 'gradual development'.

That is, Darwin explained the origin of the different species by a gradual development from a common ancestor under the selection pressure of the two Darwinian principles of the variation of the species and the survival of the fittest.

The use of the word in a technical sense should be restricted, IMHO, to processes where these two principles of natural selection are at work.

Garth

OK... and here's the but... but... what's the difference between matter that is "life" gradually developing into variations of species and gases gradually developing into a sun? There are natural selections involved (and evolved) in both cases. And some gases are fit to "survive" the process and some are not.

This is simply for the sake of discussion since I realize that there are specific terms for specific processes for reasons of clarity and separation of elements.

 

[Garth]

Is there competition for survival, predators, when clouds of gas condense down under their own gravity to form stars?

Garth

 

[baywax]

Is there competition for survival, predators, when clouds of gas condense down under their own gravity to form stars?

Garth

We'd have to ask a gas cloud!

Apparently there's one attached to the Milky Way right now!

Cosmic Finger Taps Our Galaxy's Shoulder

This extremity of hydrogen gas is actually the pointy end of the so-called Leading Arm of gas that streams ahead of two irregular galaxies called the Large and Small Magellanic Clouds.

http://www.space.com/scienceastronomy/080205-st-galaxy-finger.html

 

[baywax]

Garth... "competition for survival" and "predators" are conditions we, as humans, are able to observe and distinguish.

The animals, the birds, fish, bugs and plants we are able to make observations about are unable to classify these conditions of survival, predation and competition. In this way... they resemble a gas cloud which has no knowledge of these terms, yet is subject to conditions that could be construed as similar to those determining natural selection.

 

[oldman]

Garth... "competition for survival" and "predators" are conditions we, as humans, are able to observe and distinguish.

The animals, the birds, fish, bugs and plants we are able to make observations about are unable to classify these conditions of survival, predation and competition. In this way... they resemble a gas cloud which has no knowledge of these terms, yet is subject to conditions that could be construed as similar to those determining natural selection.

Setting aside the precise meaning and application of the word "evolution", which has been well explored in this thread, it seems clear to me that diverse processes of gradual development, such as our descent from "worms and worse" and the development of our astronomical environment, do have features in common --- as you seem to be agreeing here, baywax. Such evolutionary processes (if I may still use this adjective, Garth) seems to rely on specific "tricks" (again for want of a better word); reproduction in the biological case, gravity in the astronomical case. Do such tricks have some special character in common, other than the kind of process they stimulate?

 

[baywax]

Setting aside the precise meaning and application of the word "evolution", which has been well explored in this thread, it seems clear to me that diverse processes of gradual development, such as our descent from "worms and worse" and the development of our astronomical environment, do have features in common --- as you seem to be agreeing here, baywax. Such evolutionary processes (if I may still use this adjective, Garth) seems to rely on specific "tricks" (again for want of a better word); reproduction in the biological case, gravity in the astronomical case. Do such tricks have some special character in common, other than the kind of process they stimulate?

I agree with Garth in that language offers the clarity of a classification system. So that when we say "evolution" we know we are talking about the progress of biological systems from one complexity to the next. When we say "develops" we know that the term applies to more than just biological systems. Take film or the weather for example. Its not incorrect to say a storm "evolved" out of the clouds. But it confuses a specifically biological term with a development that is not biological.

It may be that we can apply the term "evolution" to non-living systems but that would be confusing in the long run and has already come to be at cross-purposes with the function of the term "evolution" and its original meaning as intended by the theorist, Charles Darwin.

The Inuit of the north have 23 words that describe various conditions of snow. Certain tribes of Filipino peoples have a language that can be transposed into music and their music can be transposed into their language. These are adaptive and diverse features of language. With english we tend to homogenize our terms to the point of "sick" meaning "good" and "evolve" meaning a trip down the highway. Each culture treats its language with varying respect and disrespect and each culture lasts about as long as the respect for their language (and ethics) lasts. So, in the interest of future generations, I recommend sticking to specific terms for specific usage, or prepare to witness the fall of the english language and everything associated with it.

 

[CaptainQuasar]

It seems to me that the formation of crystals would be another example of the sort of thing oldman is talking about. These things are similar in that they're self-perpetuating within an environment that doesn't disrupt them but I don't think that there's some kind of underlying secret here. I think it's just an abstract pattern that human minds would be inclined to pick out, the way in science we talk about ‘the law of this’ and ‘the law of that’ without worrying about where the lawyers are.

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[baywax]

It seems to me that the formation of crystals would be another example of the sort of thing oldman is talking about. These things are similar in that they're self-perpetuating within an environment that doesn't disrupt them but I don't think that there's some kind of underlying secret here. I think it's just an abstract pattern that human minds would be inclined to pick out, the way in science we talk about ‘the law of this’ and ‘the law of that’ without worrying about where the lawyers are.

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Sure but we don't talk about the crystal's metabolic processes... even though there may be processes to do with the crystal that resemble a metabolic process. (ie: born in the "bowels" of the earth".

 

[CaptainQuasar]

I wasn't saying that crystals are like metabolic processes. I'm saying that the formation of the crystalline molecular structure out of an amorphous quantity of matter is a self-assembling, self-perpetuating process within that quantity of matter.

To recap, oldman is pointing out things like biological evolution, the coalescence of planets, stars, and galaxies via gravity, and the development of complex social structures are all self-perpetuating processes. A salient observation but I don't think there's any magic happening underneath or any fundamental substructure of reality exposed here.

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[baywax]

I wasn't saying that crystals are like metabolic processes. I'm saying that the formation of the crystalline molecular structure out of an amorphous quantity of matter is a self-assembling, self-perpetuating process within that quantity of matter.

To recap, oldman is pointing out things like biological evolution, the coalescence of planets, stars, and galaxies via gravity, and the development of complex social structures are all self-perpetuating processes. A salient observation but I don't think there's any magic happening underneath or any fundamental substructure of reality exposed here.

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I can see that. And these geological and astronomical processes could be labeled as evolutionary... but we could also refer to the composition and processes of the sun as the "metabolism" of the sun... and that would be just a wrong and misleading as saying that a sun has "evolved" from a cloud of gas via gravity etc.

These terms, "evolution" and "metabolism" and other biological terminology are specifically designed to describe biological process. Biology is the study of life... not the study of astronomy and not of geology.

I'm not against metaphor... but I believe it has its place... such as in novels and short stories... not as a descriptive device used to explain the processes of every natural phenomenon.

I mean its fun to be able to describe how the Horse Head Nebula may one day evolve into a solar system. But using the word evolve in this instance means the listener or reader must know the original meaning of the word Evolve. In fact the OP of this thread is asking how evolution works?

Do we tell them its when a gas condenses enough under its own gravity to become a sun? Or do we tell them about survival, competition and natural selection in biological process etc..?

 

[CaptainQuasar]

I think everyone's kind of getting hung up on terminology. He isn't trying to make biological analogies, except insofar as he's asking whether there's a common phenomenon underneath all these things.

It's an intelligible question whether he's using the franchise-authorized terminology or not. Presuming one's conclusions by stretching terminology to fit it is annoying, yes, but it would demonstrate superior virtue on our part to just pretend he's speaking a foreign language or something and address his question now that this is heading into the fourth page of discussion.

It would be one thing if he'd put something like this in one of the science forums - perhaps that would somehow provide justification to be snobbish about terminology - but this is the philosophy forum.

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[baywax]

I think everyone's kind of getting hung up on terminology. He isn't trying to make biological analogies, except insofar as he's asking whether there's a common phenomenon underneath all these things.

It's an intelligible question whether he's using the franchise-authorized terminology or not. Presuming one's conclusions by stretching terminology to fit it is annoying, yes, but it would demonstrate superior virtue on our part to just pretend he's speaking a foreign language or something and address his question now that this is heading into the fourth page of discussion.

It would be one thing if he'd put something like this in one of the science forums - perhaps that would somehow provide justification to be snobbish about terminology - but this is the philosophy forum.

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OK, didn't mean to get snobby about evolution. Discipline of terms is a touchy subject. Half or more of philosophy is all about definition of terms. So, the question might better read "how does evolution work in philosophical terms?"

Philosophically and for the sake of clarity I'd say "evolution" is a term that belongs to the biological sciences which describes physiological changes taking place in living matter and how these changes are brought about by life's interactions with the environment.

It is possible to "imagine" the environment as going through a similar process of evolution and to see biological evolution as a reflection and adaptation to an "environmental evolution". Because life is composed of the same matter as the environment in which it is found, it becomes even easier to metaphorically apply the concept of biological evolution to the changes that may or may not take place in the environment.

;-)

 

[oldman]

I agree with Garth in that language offers the clarity of a classification system. ...Yes indeed, I do agree - OM. ...Each culture treats its language with varying respect and disrespect and each culture lasts about as long as the respect for their language (and ethics) lasts. So, in the interest of future generations, I recommend sticking to specific terms for specific usage, or prepare to witness the fall of the english language and everything associated with it.

Thanks, baywax, for explaining your stance so clearly; you must feel strongly about my use of words. I’m afraid I hadn’t realized how sensitive philosophy folk are about such matters, but I’ve now been enlightened by the way this thread has developed (see, a lesson has been learnt!).

However I’m a recidivist, and can’t fully agree with you. While cultures like that of the Inuit, or of Filipino tribes, may last only as long as they respect their language and culture, this is not true of we English-speaking peoples, whose language and culture has for many hundreds of years been (dare I say) evolving in a way that more closely resembles biological change than in the situations listed in the OP. Proof is that the Canterbury Tales are difficult to read in their original form, but are still respected and part of our culture --- which has proved to be the fittest for survival — if one judges fitness by numbers, as Nature seems to do in the case of biological evolution.

The possibly unintended result is that you have induced in me the secondary hope that this thread will help to broaden the meaning of “evolution”, rather than jealously to preserve it as strictly Darwinian, in cases where I believe this to be unnecessarily restrictive in conveying meaning!

It seems to me that the formation of crystals would be another
example (and one of the best. Thanks for bringing it up) of the sort of thing oldman is talking about. These things are similar in that they're self-perpetuating within an environment that doesn't disrupt them but I don't think that there's some kind of underlying secret here ...

In fact, Cap’n Q., once upon a time (as in novels and short stories, baywax) there was indeed a most clever underlying secret here ( I’ve called this sort of thing a “trick”, in my previous post). The key to crystal growth is the intersection of a topological lattice defect known as a “screw dislocation” with the crystal surface. The recognition of this trick by the late, great, Sir Charles Frank of Bristol University some 55 years ago caused quite a stir, because it solved the mystery of how crystals grow under conditions where theoreticians said they couldn’t. Ain’t Nature wonderful?

I'm saying that the formation of the crystalline molecular structure out of an amorphous quantity of matter is a self-assembling, self-perpetuating
process

Just so, Cap’n, Sir.

I mean its fun to be able to describe how the Horse Head Nebula may one day evolve into a solar system...

Just a concluding niggle... such nebulae are usually huge compared to the solar system and, as is happening in the fuzzy bit of Orion, are likely to evolve into many solar systems.

 

[CaptainQuasar]

...the secondary hope that this thread will help to broaden the meaning of “evolution”, rather than jealously to preserve it as strictly Darwinian, in cases where I believe this to be unnecessarily restrictive in conveying meaning!

It might be effective to adopt another term, perhaps something like “systemic autoconvolution” (etymologically a system that rolls itself up), to denote processes or phenomena that are organizing and self-perpetuating. Even if just for the duration of this conversation.

I do agree with the other guys that there's a terminology conflict in that at this point in history evolution connotes some very specific mechanisms - it implies implementation as well as function, as we would say in software engineering. http://en.wikipedia.org/wiki/Evolutionary_computation" , for example, is a form of analysis that uses a technique that is not only organizing and self-perpetuating but also employs specific Darwinian mechanisms such as heredity and natural selection. As I said that by no means makes your idea unintelligible but it obviously is preventing people from being able to see the forest for the trees here.

“Systemic autoconvolution” is certainly clumsier but there are zero Google hits on it at the moment so presumably there's no one to get jealous.

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[oldman]

It might be effective to adopt another term, perhaps something like “systemic autoconvolution” (etymologically a system that rolls itself up), to denote processes or phenomena that are organizing and self-perpetuating. Even if just for the duration of this conversation.

It's certainly clumsier but there are zero Google hits on it at the moment so presumably there's no one to get jealous.

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Right! Excellent suggestion, henceforth accepted by me. Perhaps one could use the acronym SAC for short. Then all I have to do is explain why evolution (in the Darwinian sense) is a SAC process. Hmmmm...

Of course this acronym could be dangerous if important folk mix it up with Strategic Air Command.

 

[CaptainQuasar]

Well, since you liked that one, how about we express the “tricks” as “organizational attractors”. As you said, in the formation of cosmological structures the organizational attractor is gravity, in biological evolution it's reproduction (specifically self-reproduction utilizing Darwinian mechanisms), and in crystal growth it's this screw dislocation principle and a http://en.wikipedia.org/wiki/Tessellation" , to mention our friend there.)

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[baywax]

It might be effective to adopt another term, perhaps something like “systemic autoconvolution” (etymologically a system that rolls itself up), to denote processes or phenomena that are organizing and self-perpetuating. Even if just for the duration of this conversation.

I do agree with the other guys that there's a terminology conflict in that at this point in history evolution connotes some very specific mechanisms - it implies implementation as well as function, as we would say in software engineering. http://en.wikipedia.org/wiki/Evolutionary_computation" , for example, is a form of analysis that uses a technique that is not only organizing and self-perpetuating but also employs specific Darwinian mechanisms such as heredity and natural selection. As I said that by no means makes your idea unintelligible but it obviously is preventing people from being able to see the forest for the trees here.

“Systemic autoconvolution” is certainly clumsier but there are zero Google hits on it at the moment so presumably there's no one to get jealous.

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This is a nice gesture but the cross-pollination occurring amongst terminologies is already rampant as is well demonstrated by terms such as "genetic algorithms" which you have touched upon with the "evolutionary computation". The computer obviously has no genes yet is apparently capable of genetic functions.

http://www.aaai.org/aitopics/html/genalg.html

The opening sentence on this page explaining what genetic algorithms are goes like this:

"[G]enetic algorithms are based on a biological metaphor: They view learning as a competition among a population of evolving candidate problem solutions."

So, right off the bat, the author has qualified the use of a biological term as it applies to computation.

What I called cross-pollination of terms, as oldman has pointed out, must have caused and must still cause some consternation between nations and peoples. For the Germanic peoples to see the word "gut" (which means good) turned into a word that means the organs of a body in the english speaking world must have turned their stomach... verily!

 

[oldman]

Well, since you liked that one, how about we express the “tricks” as “organizational attractors”...

I've no difficulty with “organizational attractors”, except for a prejudice against long words (despite being accused by Cyrus in post # 10 of having "a lot of big words in your posts mixed in with science" ). Would this name imply a link with chaos theory?

By the way, you mention crystal growth and molecules in the same breath, as it were, whereas I tend to think of crystals with dislocations as being made of individual atoms, but for no good reason. Perhaps I should broaden my outlook, as it strikes me that DNA molecules, which are big but crystallise, have a spiral form. And the spiral nature of a http://en.wikipedia.org/wiki/Screw_dislocation#Screw_dislocations" is exactly what promotes crystal growth. Could this have implications for the evolution of the DNA molecule, I wonder?

 

[russ_watters]

I don't have time to go into it now, but as said before, this thread is simply about the refusal to accept that "stellar evolution" (or various other kinds) and "biological evolution" are two completely separate concepts and do not share a single set of governing principles.

One fundamental difference is the lack of a random element in "stellar evolution". You can take two clouds of hydrogen of a given mass and density and be able to predict with an extremely high degree of accuracy what the life cycle of the resulting star will look like. You cannot do the same with biological evolution.

There is no philosophical question here. Only a refusal to accept that there are different definitions for the same word.

 

[baywax]

Generally I'd say oldman has hit upon something that I've proposed in other threads involving discussions about the origin of the "survival instinct".

When oldman sees a congruency between crystal formation and the evolution of DNA he's touching on my question that goes like this:

Is the nature of "survival" confined to biologically organized matter or is the propensity to survive inherent in all the universe's laws and elements? (If there were no laws of survival included with physical laws, would there be a universe?) Does this question use the term "survival" incorrectly?

 

[CaptainQuasar]

I've no difficulty with “organizational attractors”, except for a prejudice against long words (despite being accused by Cyrus in post # 10 of having "a lot of big words in your posts mixed in with science" ). Would this name imply a link with chaos theory?

That's where I got the term from, yeah. But I'm not implying any Lorentz-attractor-type math underneath it.

I was also thinking of "organizational principle" but that sounds a little too abstract.

By the way, you mention crystal growth and molecules in the same breath, as it were, whereas I tend to think of crystals with dislocations as being made of individual atoms, but for no good reason. Perhaps I should broaden my outlook, as it strikes me that DNA molecules, which are big but crystallise, have a spiral form. And the spiral nature of a http://en.wikipedia.org/wiki/Screw_dislocation#Screw_dislocations" is exactly what promotes crystal growth. Could this have implications for the evolution of the DNA molecule, I wonder?

Now that you've linked to screw dislocation it makes sense that this would be involved in the crystallization of DNA. But I think that would only apply to helical molecules, right? Crystallization of sodium chloride / salt is simply a lateral dislocation, like cubes packed together. It's all just mathematical http://mathworld.wolfram.com/Packing.html" problems.

I don't have time to go into it now, but as said before, this thread is simply about the refusal to accept that "stellar evolution" (or various other kinds) and "biological evolution" are two completely separate concepts and do not share a single set of governing principles.

One fundamental difference is the lack of a random element in "stellar evolution". You can take two clouds of hydrogen of a given mass and density and be able to predict with an extremely high degree of accuracy what the life cycle of the resulting star will look like. You cannot do the same with biological evolution.

There is no philosophical question here. Only a refusal to accept that there are different definitions for the same word.

Yeah, they do share a set of governing principles. Like I said, they're both self-perpetuating processes that organize their substrate medium.

oldman gave other examples even in his original post: development of social structures and development of technologies. And now we're talking about crystal formation.

I would agree that there isn't any underlying universal mechanism involved here but the principles are the same. To assert that this isn't a valid observation is silly. Give the vocabulary stuff a rest, will you?

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This points out to me that there's a third concept involved here. In addition to systemic autoconvolution itself and the organizational attractors or organizational principles, there's a different substrate medium in each case. In the case of biological evolution, astronomical structures, and crystals the substrate is matter and in the case of social structures and technology the substrate is http://www.jom-emit.org/" .

You know, maybe this is part of the reason why memetics is being so slow to develop as a field. I think it really needs to be viewed much more abstractly, as a matter of patterns or mathematics, to get properly bootstrapped as a science. People focus too much on the analogy to genetics. Another terminology problem, sigh...

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[CaptainQuasar]

http://www.upcomillas.es/webcorporativo/Centros/catedras/ctr/Documentos/TRIABIECarreira06.pdf" is drawing the same paralells. From page 8:

We seem, therefore, to be in a position to attribute life to the same play of necessity and chance that produces a galaxy or a crystal.

And this Science Frontiers article makes an analogy between the arrangement of galactic superclusters and crystals in an article called http://www.science-frontiers.com/sf110/sf110p03.htm" :

Recent redshift measurements, however, hint more and more forcefully that the huge superclusters of galaxies are almost as neatly arranged as the atoms in a crystal.

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Hmm... just as a tangent, I wonder how long after the Big Bang that crystalline matter first appeared in the universe.

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[russ_watters]

Yeah, they do share a set of governing principles. Like I said, they're both self-perpetuating processes that organize their substrate medium.

I'll grant you that, but that's pretty broad. They share some general purpose features of the definition (that's why the name was chosen), but they also have other governing principles that they don't share. The random element is an important one for the OP's discussion because he seems to be implying that evolution has a direction. The fact that you cannot set up a set of initial conditions and run a simulation that closely matches biological evolution is a critical difference in the two definitions.

It's easier to see if you just look it up in the dictionary. The word "evolution" has a number of general purpose definitions and a few special purpose definitions. The "biological evolution" definition is a subset of the general purpose definitions, but not vice versa. Ie, you can apply the general purpose definition "any process of formation or growth; development" to both biology and cosmology, but you cannot apply the special purpose definition "change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift" to astronomy. They are, for practial purposes, different words.

oldman gave other examples even in his original post: development of social structures and development of technologies. And now we're talking about crystal formation.

Yes. All these are examples of not being the same thing as biological evolution.

I would agree that there isn't any underlying universal mechanism involved here but the principles are the same. To assert that this isn't a valid observation is silly. Give the vocabulary stuff a rest, will you?

In a disagreement about a definition, the vocabulary stuff is everything.

...memetics...

Continuing with the above tack, the definition of "meme" says explicitly that it is an analogy, as you correctly point out below. It's a similar concept, but not the same thing.

... is being so slow to develop as a field. I think it really needs to be viewed much more abstractly, as a matter of patterns or mathematics, to get properly bootstrapped as a science.

That second sentence is self-contradictory. Viewing/approaching something abstractly is precisely the opposite of what we go for with science.

 

[russ_watters]

Lets have another look at the OP's question:

The details of how evolution (if this is indeed the right term to use) operates in each case are of course different. The purpose of this post is to ask folk who take an interest in the whys and wherefores of such matters (those who have a philosophical bent and some knowledge of physics?) if there could be a common factor that defines “evolution”.

Now please don't take my position the wrong way: I have, in fact, argued in favor of such things as social development being evolutionary processes with similar drivers to biological evolution. I do believe that social development is a "survival of the fittest" (a "Darwinian") process. But while this is similar to biological evolution and the usage of the word is the same, things like "stellar evolution" are not.

So perhaps what we may want to do here is make two lists - one of things that follow the general biological concept of evolution and ones that don't. That's actually relatively easy since the word "evolution" predates Darwin and you can simply look at the history and development of these areas of study to find the answer. Ie, the concept of "social evolution" isn't referred to as "social evolution", it is referred to as "social Darwinism". Stellar evolution, on the other hand, is not referred to as a Darwinian process.

Now, that said, things like the pursuit of science can be considered Darwinian processes, but the cone of potential paths is inverted: biological evolution diverges, evolution of physics theories (and political/social theories) converges.

 

[CaptainQuasar]

But he's not talking about Darwinian processes. Don't you see that you're getting waaaay to hung up on the word he used and there's another conversation to be had here? That's why as soon as I suggested an alternative term that fit well he said “Great! Let's use that!”

In particular, we're also not talking about stellar evolution, which has to do with the lifecycles of stars and how the initial fusion-production of heavier elements in early stars and supernovae was necessary for the later types of stars to develop. We're instead talking about the formation of planets, stars, galaxies, and galactic clusters and superclusters by gravity. But stellar evolution might be another good one to add to the list.

You're so hung up on the word “evolution” that you're having difficulty even understanding the argument being made here.

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[CaptainQuasar]

Viewing/approaching something abstractly is precisely the opposite of what we go for with science.

I guess you're an experimental scientist instead of a theorist.

You get to the hypotheses you're going to test through abstract thinking that often violates your current understanding of the subject.

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[oldman]

I don't have time to go into it now, but as said before, this thread is simply about the refusal to accept that "stellar evolution" (or various other kinds) and "biological evolution" are two completely separate concepts and do not share a single set of governing principles.

One fundamental difference is the lack of a random element in "stellar evolution". You can take two clouds of hydrogen of a given mass and density and be able to predict with an extremely high degree of accuracy what the life cycle of the resulting star will look like. You cannot do the same with biological evolution.

There is no philosophical question here. Only a refusal to accept that there are different definitions for the same word.

I think you are being too didactic. I'm suggesting that it is interesting to consider similarities between processes which promote complexity, and that using the adjective "evolutionary" to describe them brings this out. Such similarities may be the result of a common "governing principle". Or they may not. Not the same as "refusing to accept different definitions of the same word". Perhaps there is no philosophical question here, but some discussion can't hurt.

 

[oldman]

.
Now that you've linked to screw dislocation it makes sense that this would be involved in the crystallization of DNA. But I think that would only apply to helical molecules, right? Crystallization of sodium chloride / salt is simply a lateral dislocation, like cubes packed together. It's all just mathematical http://mathworld.wolfram.com/Packing.html" problems.

Another niggle: No, there are two separate things here. The presence of screw dislocations is what makes (one) crystallisation possible at otherwise impossibly small supersaturations, whether it be of DNA or of ordinary salt. (There ain't such an animal as a "lateral dislocation", by the way.)

I was suggesting that the primeval (two) evolution of the helical DNA molecule itself, about which we seem to know little, could be linked to the helical character of a screw dislocation. But this is just an idle thought, since I know nothing about the evolution of huge molecules like DNA. But it must be quite a difficult process. Or life would spontaneously have appeared on Earth much more quickly than it apparently did.

 

[CaptainQuasar]

The presence of screw dislocations is what makes (one) crystallisation possible at otherwise impossibly small supersaturations, whether it be of DNA or of ordinary salt. (There ain't such an animal as a "lateral dislocation", by the way.)

Oh, I see, it has nothing to do with packing. I hadn't read enough of the article.

That's an interesting theory about the relationship to the origin of DNA. Thanks for taking the time to explain it.

(Heh, the reason I misunderstood the screw dislocation stuff in the first place is because I got hung up on the meaning of the word "dislocation".)

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[CaptainQuasar]

And by the way, it does make sense to speak of crystals as essentially single large molecules with atoms as their components, it's more descriptive than regarding them as aggregations of molecules.

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