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  #11  
Unread July 31st, 2006, 08:04 PM
Fred H. Fred H. is offline
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Default Re: Selling Evolution

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[Tom says:] Fred. I just gave you a set of facts, you mentioned no fact to dispute mine; you just threw some ignorant shadow at me.
OK genius, let’s try this one last time—saying, as you did, that “Mutation is effectively random, unless and until we can plot the paths of all energetic particles and the DNA in reproductive (sperm and egg) cells,” is akin to saying that which Monty Hall door has the prize is effectively random until Monty tells us which door the prize is behind.

Or, stated another way: Randomness is an illusion, but Tom’s ignorance is painfully real.
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  #12  
Unread August 1st, 2006, 12:04 AM
Carey N Carey N is offline
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Default Re: Selling Evolution

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Originally Posted by Fred
I'm not terribly clear what you mean by 'effectively random . . . with respect to their effect upon organisms,' but if you simply mean that 'mutation' is random . . .'
No, that is not what I meant . . . I would agree with you in abstract that, technically (in the sense that everything is determined, etc. etc.), mutations are 'non-random'. We could in principle predict which/when/where mutations would happen if we knew the exact state of every particle in the universe and were able to model their future dynamics (in practice, of course, this kind of predictive power is beyond reach).

What I really meant by "random" is that mutations occur without regard for their effect upon the adaptive design of organisms (with a few exceptions that prove the rule, but I won't go into them). In other words, mutational processes that inherently benefit organisms don't exist, and most mutations decrease an organism's ability to produce offspring. You could also think of mutation as a process that continually pushes populations toward higher entropy . . . without a complementary process that reduced entropy locally, mutation would result in lower and lower organismal fitness until the population crashed to extinction. This is one of the primary concerns with respect to very small, endangered species, in which selection cannot act strongly enough to combat mutational meltdown.

Natural selection is the complementary process that siphons and preserves order from a pool of mutational disorder . . . organisms that are best adapted to their environments preferentially contribute to subsequent generations, while less effectively-adapted organisms fail to contirbute or contribute less heritable information to subsequent generations (as you may intuit, the difference between the conitrbutions of more-fit and less-fit organisms is directly related to the strength of selection, as described by the mathematics of evolutionary genetics). Deleterious mutations are thus expunged from the population . . . to what extent this occurs depends upon the strength of selection, population size, mutation rate, reproductive mechanism of the species in question (sexual, asexual, etc.) and, in some contexts, immigration/emmigration rates. The details of why certain organisms and traits are more or less "fit" are highly context-dependent; e.g. a lizard that specializes upon swimming and consuming seaweed can do very well in a marine tidal habitat, but the same lizard is pretty screwed in a desert.

So, to re-iterate my meaning: mutations may in principle be governed by deterministic laws, but they don't preferentially benefit organisms or rain down according to a grand design. Rather, mutation is the process that drives populations toward the thermodynamic equivalent of entropy, and natural selection is the process that ultimately resists localized entropy (while allowing universal entropy to increase by the release of metabolic heat, etc.)

Last edited by Carey N; August 1st, 2006 at 12:04 PM.
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  #13  
Unread August 1st, 2006, 07:59 AM
Fred H. Fred H. is offline
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Default Re: Selling Evolution

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Carey: So, to re-iterate my meaning: mutations may in principle be governed by deterministic laws, but they don't preferentially benefit organisms or rain down according to a grand design. Rather, mutation is the process that drives populations toward the thermodynamic equivalent of entropy, and natural selection is the process that ultimately resists localized entropy (while allowing universal entropy to increase by the release of metabolic heat, etc.)
Fine post Carey—clear, concise, reasonably rigorous, not agonizingly longwinded. I hope MM, Tom, and Alex are observing and perhaps learn something. I suspect Alex will; but the other two may be a lost cause.

Anyhoo, it seems that we agree that mutation isn’t necessarily intrinsically “random,” but rather, currently, it seems to be unpredictable, at least by us humans based on our current knowledge.

Roger Penrose (in his Emperor’s New Mind), who convincingly argues that human mathematical insight is non-algorithmic, and also doesn’t see how algorithms for mathematical judgment could evolve, writes: "To my way of thinking, there is still something mysterious about evolution, with its apparent 'groping' towards some future purpose. Things at least seem to organize themselves somewhat better than they 'ought' to, just on the basis of blind-chance evolution and natural selection." (p.416). (And others have said similar things.)
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  #14  
Unread August 1st, 2006, 09:42 AM
Carey N Carey N is offline
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Default Re: Selling Evolution

Thanks for the positive feedback. I'm afraid this one's going to be a bit more long-winded. Bear with me.

Some comments on your comments:
Quote:
it seems that we agree that mutation isn't necessarily intrinsically 'random,' but rather, currently, it seems to be unpredictable, at least by us humans based on our current knowledge.
True that mutations may not be random in the grandest of grand schemes of things, but to really predict which, where, and when mutations will happen would require that we know ths state of all mutagens (UV light, mutation-inducing DNA elements, etc.) everywhere on earth (and elsewhere, since some, e.g. UV rays, descend upon us from the cosmos). To know all that information and document it in, say, a large Excel spreadsheet, seems (based on informal logic) impossible. To really monitor so much information, we'd need a computer that contains more particles than exist in the universe.

This is why I said that, in practice, mutations are not predictable - at least, not by humans. Perhaps I'm incorrect on that matter, but I'm willing to bet that a formal analysis would yield the same qualitative conclusion. Could Someone else predict all mutations? I guess so, but He'd have to be beyond the material realm of this universe, beyond the rules of physics . . . beyond human commentary. Such an entity's existence would not be subject to rational argument.


Quote:
Roger Penrose (in his Emperor's New Mind), who convincingly argues that human mathematical insight is non-algorithmic, and also doesn't see how algorithms for mathematical judgment could evolve
Well . . . that doesn't mean they didn't evolve! You have to admit that Penrose is somewhat biased (as we all are) in his conclusions. Just because he doesn't see something doesn't mean that we can't see it . . . to the next point:


Quote:
[Penrose thinks that] there is still something mysterious about evolution, with its apparent 'groping' towards some future purpose. Things at least seem to organize themselves somewhat better than they 'ought' to, just on the basis of blind-chance evolution and natural selection."
Don't get pulled in by Penrose's use of the phrase 'blind-chance evolution and natural selection' . . . it's critical to see that mutations occur effectively by blind chance (in context of the entropy discussion of my last post), while natural selection is a NON-random force that pulls order out of mutational diorder. The term 'blind-chance natural selection' suggests to me that penrose doesn't understand, or doesn't want to understand, what evolution is really about. I'm not saying he isn't a smart guy, but remember that smart guys and girls (especially successful ones) tend also to be stubborn guys and girls.

My correction for Penrose is this: evolution doesn't grope towards any kind of purpose other than increased capacity to populate the biota with copies of oneself. It may appear that evolution has been ascending a ladder of progress*, if one takes a highly anthropocentric view of the big picture, but consider that single-celled oarganisms are still the most abundant (in numbers and biomass), by a long shot, on earth. The only thing evolution does is pull a few pockets of order out of a large pool of mutational disorder (the reason why I can say mutational disorder is that mutations are effectively random with respect to their effects upon the adaptive design of organisms, as discussed in my last post). What else could be expected of a dumb algorithm? The amazing thing is the sheer complexity of organisms that have arisen from this process, which itself lacks any foresight.

So . . . I think there is quite a lot of mystery awaiting resolution in evolutionary biology, but none of that mystery (to me) suggests, hints, leans toward, or in any way implies the existence of a grand design.

-------------------------------------------------------------------------------------

* What does "progress" even mean in this context? If it means greater complexity, then humans are certainly a step forward. But defining progress in that way is really a human-induced artificiality. For evolution, progress is just the continuation of existence, in any self-reproducing form (bacteria, insects, plants, humans, whatever).
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  #15  
Unread August 1st, 2006, 12:04 PM
Fred H. Fred H. is offline
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Default Re: Selling Evolution

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[Carey said:] Don't get pulled in by Penrose's use of the phrase 'blind-chance evolution and natural selection' . . . it's critical to see that mutations occur effectively by blind chance (in context of the entropy discussion of my last post), while natural selection is a NON-random force that pulls order out of mutational diorder. The term 'blind-chance natural selection' suggests to me that penrose doesn't understand, or doesn't want to understand, what evolution is really about. I'm not saying he isn't a smart guy, but remember that smart guys and girls (especially successful ones) tend also to be stubborn guys and girls.

[Penrose said:]"To my way of thinking, there is still something mysterious about evolution, with its apparent 'groping' towards some future purpose. Things at least seem to organize themselves somewhat better than they 'ought' to, just on the basis of blind-chance evolution and natural selection."
Actually, Penrose was rather vigilant so as to avoid any unnecessary blasphemy regarding the current Darwinian dogma that decrees, as you say, that “natural selection is a NON-random force”—note that he indicated that things organize themselves better than they ought just on the basis of “blind-chance evolution” AND “natural selection." IOW, his “blind-chance evolution” is roughly synonymous with “random mutation,” but he still seemingly pays the required homage to “natural selection.” In fact I think he says somewhere that he’s a strong believer in “natural selection” . . . although I suspect that he too, not unlike me, sees “natural selection,” whether it be a top down or bottom up selection, as ultimately little more than a circular account that really doesn’t explain or predict all that much.

Which leaves us pretty much where we were back in the June 17 2006 post, Re: Implications of Somatic Behavior Choice, where you said:
Quote:
I still think there's a solid case for the argument that natural selection in practice - the process that actually occurs in the real world - is completely non-circular. The bare-bones, generalistic concept of selection as survival of the fittest has always been circular, as you and many other people in the past have repeatedly pointed out, but as soon as you begin to consider ecological detail, that apparent circularity just isn't important at all.
And, exasperated, I responded:
Quote:
OK Carey, I give up, you win: Natural selection’s “apparent circularity just isn't important at all.”

Last edited by Fred H.; August 1st, 2006 at 12:18 PM.
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  #16  
Unread August 1st, 2006, 12:37 PM
TomJrzk TomJrzk is offline
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Default Re: Selling Evolution

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Originally Posted by Fred H.
is akin to saying that which Monty Hall door has the prize is effectively random until Monty tells us which door the prize is behind.
Pardon me, but your bias is showing. What, or who, plays the Monty Hall role in your metaphor?
Quote:
Originally Posted by Fred H.
Randomness is an illusion.
Yes, that's why I said 'effectively random'. Randomness, like free will, is an illusion in a deterministic universe.
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  #17  
Unread August 2nd, 2006, 07:54 AM
Carey N Carey N is offline
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Default Re: Selling Evolution

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Actually, Penrose was rather vigilant so as to avoid any unnecessary blasphemy regarding the current Darwinian dogma that decrees, as you say, that “natural selection is a NON-random force”—note that he indicated that things organize themselves better than they ought just on the basis of “blind-chance evolution” AND “natural selection."
This paragraph doesn't make a whole lot of sense . . . for example, how does Penrose know "how things ought to organize themselves" on the basis of mutation and natural selection? That just sounds like a an academic's way of saying "I can't possibly believe that natural selection, lacking any foresight, produced biological complexity."


Quote:
[Penrose's] “blind-chance evolution” is roughly synonymous with “random mutation,” but he still seemingly pays the required homage to “natural selection.”
"Evolution" (in any phrase) and "random mutation" aren't remotely synonymous . . . any phrase with the word "evolution" in it, twisted though Penrose's may be, should refer to the proceses of change in content of heritable information between generations: selection, drift, migration, recombination, and mutation. Random mutation is a part of the evolutionary process, not a synonym for it.

Last edited by Carey N; August 2nd, 2006 at 08:18 AM.
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  #18  
Unread August 2nd, 2006, 08:53 AM
Fred H. Fred H. is offline
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Default Re: Selling Evolution

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Carey: "Evolution" (in any phrase) and "random mutation" aren't remotely synonymous . . . any phrase with the word "evolution" in it, twisted though Penrose's may be, should refer to the proceses of change in content of heritable information between generations: selection, drift, migration, recombination, and mutation. Mutation is a part of the evolutionary process, not a synonym for it.
Well Carey, as you yourself have already acknowledged at
http://www.behavior.net/bolforums/sh...90&postcount=4
Quote:
Mutation is the ultimate source of all variation present within a population . . . without mutation, there would eventually be nothing for natural selection to select, and evolution would halt.
IOW, whether selection be top down, bottom up, “natural,” “artificial,” blind, mindless, whatever, it can only select from what is already available; from, in a sense, what already has blindly, directionlessly, “effectively randomly,” changed/mutated/evolved; at least according to current Darwinian dogma.

So I don’t think it sounds like Penrose is necessarily saying, as you opine, that he "can't possibly believe that natural selection, lacking any foresight, produced biological complexity." Rather I think he’s saying exactly what he said: "To my way of thinking, there is still something mysterious about evolution, with its apparent 'groping' towards some future purpose. Things at least seem to organize themselves somewhat better than they 'ought' to, just on the basis of blind-chance evolution and natural selection."

And I’d add that while Penrose indicates that he himself is a strong believer in “natural selection,” I suspect that he, like me, may also see “natural selection,” whether it be a top down or bottom up selection, as ultimately little more than a circular account that really doesn’t explain or predict all that much.

Last edited by Fred H.; August 2nd, 2006 at 10:05 AM.
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  #19  
Unread August 2nd, 2006, 02:57 PM
Margaret McGhee Margaret McGhee is offline
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Default Re: Selling Evolution

Watching this one form the sidelines I see that Fred states that selection proceeds:
Quote:
. . from, in a sense, what already has blindly, directionlessly, “effectively randomly,” changed/mutated/evolved; at least according to current Darwinian dogma.
It seems to me that the disconnect here is in defining mutation as random - which is effectively true (true at the level of the organism) - and asserting that therefore evolution is random - which is certainly not true.

The theory of evolution is the scientific description of a process, a mechanism, whereby species can change over time to adapt to their environment - which is also changing randomly (unpredictably at the level of the organism).

A mechanism, whether natural or man-made can have many elements working together to provide a function. That one element of the mechanism uses the quality of randomness to provide a source of information that is used by other elements of the process - does not make the process random.

This seems to me similar to a random number generator in a computer game - such as when dealing the deck in free cell. Depending on the deal sometimes the player may win, sometimes they lose. Much like mutations sometimes enhance fitness and sometimes reduce fitness. Since an organism has no way of knowing ahead of time which ones will do better, or just how their environment might change around them, the effective randomness of mutations allows whatever possible designs that come up - to be tried out in the game of life - in the existing unpredictable environment.

Since environments themselves are effectively random at the level of the organism (volcanoes, hurricanes, CO2 concentrations, migration of predators, disease organisms, etc.) what better way could be devised for species to adapt than for each generation to be able to select the best possibilities from a random set.

The result is that species evolve in a very non-random way - always in a way to optimize their survival in their existing environment. The randomness of mutations provides a crucial type of information that allows non-random evolution to proceed - to track a randomly changing environment.

I don't offer this as a better explanation than Carey's. More to see if I've got it right so please tell me if I don't. BTW Carey, I really appreciated your explanation of evolution in terms of thermodynamics. I've never seen that done so clearly.

Margaret
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  #20  
Unread August 2nd, 2006, 05:30 PM
Fred H. Fred H. is offline
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Default Re: Selling Evolution

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MM: Since environments themselves are effectively random at the level of the organism (volcanoes, hurricanes, CO2 concentrations, migration of predators, disease organisms, etc.) what better way could be devised for species to adapt than for each generation to be able to select the best possibilities from a random set.

The result is that species evolve in a very non-random way - always in a way to optimize their survival in their existing environment. The randomness of mutations provides a crucial type of information that allows non-random evolution to proceed - to track a randomly changing environment.
If, as MM asserts, “environments themselves are effectively random,” which is how I think most Darwinians would generally see things, and if we’re talking about a top-down “natural selection,” as we generally are in Darwinian natural section, then natural selection itself, a product of blind natural forces operating in environments that “themselves are effectively random,” would also, ultimately, be “effectively random.” IOW Carey, MM is effectively showing you, unwittingly perhaps, that if we are to be at least somewhat consistent in our reasoning, then you essentially have it wrong when you assert that Darwinian “natural selection is a NON-random force”—Darwinian natural selection would be as “effectively random” as Darwinian mutations.

(I’m so glad MM is on your side.)
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