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Author Topic:   Criticizing neo-Darwinism
nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 77 of 309 (299515)
03-30-2006 12:48 AM
Reply to: Message 70 by Wounded King
03-29-2006 3:51 AM


Re: Holey fitness lanscapes Batman!!
You seem to have suddenly decided to discuss a completely different topic entirely.
That's what you should have expected.
I have not claimed that neo-Darwinism is false, nor that I would refute it. Generally, a theory is a construct that fits reality. My complaint is that it doesn't fit very well. Thus we should see example of poor fit in many aspects of the theory.
There is a frequent argument (against ID, for example) that a theory has to make testable predictions. But the same reasoning should favor a theory that makes strong predictions over a theory that makes vague or weak predictions. I am arguing that neo-Darwinism is a poor fitting theory that often makes only weak predictions. We should be able to do better.
As PaulK so cogently points out, if the only change that is going on is in the location of the deer then there is no evolution going on.
Right. So you reach into your grab bag of fudge factors, to declare that the theory doesn't apply in this case. It's a sign that the theory is a poor fit. The same sort of argument, if made by a creationist, would he called "add hoc reasoning".
You seem to want neo-darwinism to do much more than it has ever claimed to be able to. In fact you seem more to want some sort of grand unified theory of biology.
I'm not looking for a grand unified theory. I am skeptical of such. But a theory that deals with adaptation should recognize that one way of adapting is to move to an environment where the organism is already adapted.

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nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 79 of 309 (299518)
03-30-2006 1:29 AM
Reply to: Message 76 by RAZD
03-29-2006 9:17 PM


Re: Expanding my, um, muddled thoughts on sex ...
My reservation about sexual selection, is that when I see this used in an explanation it always seems ad hoc.
At it's simplest {form\level\degree} it means not wasting mating {time\behavior\energy} on non-viable mates -- mates of other species where offspring would be sterile at best.
In such a case you have a fitness explanation. So why bring in sexual selection?
We also see that "species recognition" can define a (new) "species" before genetic isolation occurs ...
Again, that seems to be a fitness explanation.
Many of your other examples seem to be fitness explanations.
For comparison, look at Bonobos: they practice indiscriminate sex at the drop of a hat, and compared to Chimpanzees they are less well adapted to their environment (smaller populations, more marginal areas, probably headed for extinction even without the hunting by humans).
That seems like a weak argument. You can find other species probably headed for extinction, where sex is not so indiscriminate.
The question of sexual selection is probably a side issue, and perhaps should have a separate thread if you want to discuss in more detail.

This message is a reply to:
 Message 76 by RAZD, posted 03-29-2006 9:17 PM RAZD has replied

Replies to this message:
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nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 84 of 309 (301013)
04-04-2006 10:50 PM
Reply to: Message 83 by RAZD
04-02-2006 6:13 PM


Re: Expanding my, um, muddled thoughts on sex ...
The question of sexual selection is probably a side issue, and perhaps should have a separate thread ...
There is one available, the {Sexual Selection, Stasis, Runaway Selection, Dimorphism, & Human Evolution} thread.
Thanks for the reference. I did find it an interesting thread.
But the issue you raised on neo-darwinism is the mechanisms by which novel genetic changes become expressed in populations.
One answer is sexual selection.
In my opinion, it cannot explain all (or even most) novelty.

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nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 93 of 309 (304049)
04-13-2006 7:42 PM
Reply to: Message 90 by extremophile
04-12-2006 2:11 PM


Re: Why prejudge?
How come "biology" explains complexity apart from neodarwinism?
I am using "neodarwinism" to refer to a mathematical theory of change in population genetics. You can, in principle, see what is predicted in this theory without having to refer back to what is observed.

This message is a reply to:
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nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 94 of 309 (304051)
04-13-2006 7:47 PM
Reply to: Message 91 by extremophile
04-12-2006 3:04 PM


Re: gould vs dawkins *ding ding*
And PE has yet more problems with contingencies than ND, when it comes to explain adaptation. While in ND, there is a large number of individuals being selected over generations, thus compensating for eventual lesser adapted individuals that got lucky, and for better adapted individuals that did not reprodue or reproduced less because of bad luck, with species selection is more like a single event, more prone to the disturbs of contingencies.
I have not been suggesting group selection (species selection). I'm a bit surprised to see you suggest that group selection is part of PE.
Not to mention that PE alone (somehow... because I do not think it can possibly be proposed anyway) would require much more time to develop a adaptation such as the camera-like eye.
I don't understand that comment at all. Moreover, I don't consider the mammalian eye to be camera-like.

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nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 98 of 309 (304316)
04-14-2006 8:17 PM
Reply to: Message 96 by extremophile
04-14-2006 1:07 AM


I am not sure if I understood it. By this phrase solely, seems a bit that you mean that you are basically okay with natural selection being responsible for adaptations; but does not feel so secure about the mathematical description...?
Actually, I am critical of what I consider an over-emphasis on natural selection (sometime described as pan-selectionism).
But guessing a bit further (partly based on what I (may) remember from your posts in this thread), you are okay with the evolution of the traits per se (maybe by natural selection) but at the same time you have the impression that something entirely new is needed sometimes, rather than the more visible action of natural selection, that is the tuning of what is already there?
I'm okay with evolving of new traits. But I think neo-Darwinism doesn't adequately explain it.
Group selection is a lot more powerful to explain adaptation, because the selection of groups within a species probably is far more frequent than the extinction of a species resulting from the encounter of two species adaptad to the same niche in the same habitat.
There are several published articles that claim to debunk the idea of group selection.
I mean, the is much more likely to a adaptation (specially the complex ones) to evolve by the selection of individual traits than of species’ traits because all that takes to the gradual change and fixation of a trait within a population happens much more quickly than the extinction of species, that may not even be related to a very specific adaptation, but to the overall adaptation and eventualities such as population size.
Okay, I guess that explains the comment. I'm not sure why you see PE as involving the selection of "species' traits". It is my impression that PE advocates tend to downplay the role of selection, and instead look to the importance of environmental contingencies.
Moreover, I don't consider the mammalian eye to be camera-like.
It is not just the mammalian eye, but the vertebrate eye in general; and I think that is not a matter of individual opinion, but of consensual similarity of the structures that work very in the same way;
Yes, I should have said "vertebrate eye". I guess I disagree with the consensus. The camera is a very precise piece of machinery. If it gets a little out of whack, it won't function properly. The eye is cruder, but far more robust - it doesn't need that degree of precise tuning. The camera uses a complex compound lens, designed to cancel out chromatic aberration and spherical aberration. The eye lens is of a simpler "bag of fluid" structure, and pretty likely results in both chromatic aberration and spherical aberration. If the eye were really forming an image on the retina, then these aberrations would cause poor vision. However, I think it better to see the retina as a matrix of sensory detectors that are inserted in the visual field, each able to analyze part of the received information somewhat independently of one another. The camera uses a shutter with short exposure time to avoid the blur in the image if there is too much motion while taking a picture. The eye appears to be based on motion, with the eyes moving in saccades to generate motion that is to be detected by the retinal sensors. There is nothing in a camera that corresponds to the visual cortex of the brain.

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nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 106 of 309 (344833)
08-29-2006 6:09 PM
Reply to: Message 105 by Brad McFall
08-29-2006 8:10 AM


Re: back to NWR
Hi Brad.
I had hoped to have written up something detailed by now. But there is never enough time to do everything you want.
Let me comment in broad strokes.
I tend to look at evolution as a kind of learning system - learning by trial and error. Some people see learning as the basis for intelligence, so that would mark the processes of evolution as intelligent (in some sense of that word).
The conventional wisdom connects intelligence with consciousness. I don't. I connect it with the weak form of intentionality I mentioned in the last paragraph of Message 219. Conventional wisdom also connects learning with the ability to make true/false decisions. But I require only the ability to make pragmatic judgements (to go with what works).
Natural selection is a system that makes such pragmatic judgements. But if biological systems are intelligent (in the sense I indicated above), they ought to be able to learn to do better than just plain neo-Darwinian selection. I believe they have indeed learned to do better, and that evolution works better than one could conclude if one assumed only the neo-Darwinist mathematical model.
JAD wanted to exclude the environment a posterioriwhen not already, from ontongeny.
JAD assumes determinism, and a fairly strong form of determinism at that. With such an assumption, everything that happens is already laid out in the "plan" that determines future events. If evolution has happened in the past, then it is only because that was part of the "plan". Hence he sees the evolution that has happened as prescribed by the "plan". That leads to his "prescribed evolutionary hypothesis". Thus to JAD, the detailed processes documented in the theory of evolution are mere artifacts of carrying out the "plan."
What JAD apparently fails to notice, is that under his assumed determinism, science itself is an illusion. What scientists discover is merely a carrying out of the "plan". Likewise, his PEH is pointless. It will be adopted if the "plan" so dictates, otherwise it won't be adopted.
Personally, I favor some kind of indeterminism. But I readily admit that no empirical evidence could distinguish between determinism and indeterminism.
NOTE to readers: If you are wondering who is JAD, then check his A Prescribed Evolutionary Hypothesis.

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nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 282 of 309 (593932)
11-30-2010 1:25 PM
Reply to: Message 279 by Bolder-dash
11-30-2010 11:37 AM


Re: Nice
Bolder-dash writes:
I just want to say (before Percy finds another bullshit excuse for suspending me again) that this is one of the best posts I have ever read here from a evolutionist or anyone for that matter.
Given the general quality of your arguments, I should perhaps consider your post as damning with faint praise.
To make my position clear, I am a proponent of evolution, and have been so for several decades. I was never a creationist, though there was a period when I was undecided as to whether evolution was a satisfactory explanation.
As for neo-Darwinism, there are actually a number of evolutionists who do not consider themselves to be Darwinists. Here are a couple of examples:
Allen MacNeill, Cornell University
Larry Moran, University of Toronto

Jesus was a liberal hippie

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nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 286 of 309 (593994)
12-01-2010 1:47 AM
Reply to: Message 284 by Bolder-dash
12-01-2010 1:24 AM


Re: Nice
Bolder-dash writes:
If you like to be called an evolutionist, you can be called that, it is irrelevant to me.
Actually, I prefer to be called a mathematician. Strict usage would be that only evolutionary biologists are called "evolutionists". But creationists use the term broadly, so I guess we all are forced to use it broadly.
Bolder-dash writes:
At least you understand that even while wearing your name tag, you still are allowed to think and question (the true definition of the skeptic, not the definition that has been hijacked by atheists.)
I'm pretty sure that most of the people who have disagreed with me in this thread, also think for themselves and question. The main difference is that they want to use the term "neo-Darwinism" more broadly than I.
Bolder-dash writes:
The thing is, as soon as you start changing the paradigm, and loosen your grip on the classic neo-Darwinian model of randomness plus selection you allow all kinds of crows into your cellar that atheists adamantly do not want to let in-and that is why guys like Dawkins refuse to budge, and guys like PZ Myers are caught in a trap that they either don't realize or just don't want to admit.
I'd say that PZ Myers understand how it works quite well, and is not caught in any trap.
Bolder-dash writes:
Because without this critical component of random mutations, this throwing out of the word "synthesis" can't keep the crows out.
I'm not sure what kind of problem you have with random mutations. Like it or not, there are random mutations, and they are an important part of biological evolution.
Bolder-dash writes:
This is what honest scientists have to ask, and MacNeil and Moran are not the only ones.
I'm pretty sure that Moran and MacNeill are both athiests, and I'm equally sure that they would both disagree with just about everything you have written in this thread.
Bolder-dash writes:
And let's be honest here, you can sense the near panic levels of discussion most of the people on this board and others have when approaching this subject.
Get used to it. The evidence strongly supports evolution. The evidence does not support ID. Nobody is in panic about this, except perhaps the ID proponents.

Jesus was a liberal hippie

This message is a reply to:
 Message 284 by Bolder-dash, posted 12-01-2010 1:24 AM Bolder-dash has replied

Replies to this message:
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nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 291 of 309 (594017)
12-01-2010 8:18 AM
Reply to: Message 288 by Bolder-dash
12-01-2010 2:25 AM


Re: Nice
Bolder-dash writes:
If you want to run from your own remarks now, that's your choice.
LOL. Presumably, you are misreading what I have said.
Bolder-dash writes:
How important of a part are they? 20% of all the development of life as we see it? 30%?
You can't quantify it that way.
It's like saying "The brain is part of what keeps you alive. What percentage part? Is it 20%?"
That makes no sense, because the brain is a necessary part. Similarly, the mutations are a necessary part of the evolutionary process.
Bolder-dash writes:
You are in the same place PZ Myers is in. If it can't account for all, what accounts for the rest?
This is a silly way of looking at things. It's no wonder that you are confused.

Jesus was a liberal hippie

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nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 295 of 309 (594043)
12-01-2010 11:35 AM
Reply to: Message 293 by Bolder-dash
12-01-2010 10:32 AM


Re: Nice
Bolder-dash writes:
Aren't you even going to attempt to explain that if neo-Darwinism is in adequate to explain the development of novel features and the like, what is adequate to explain it?
If you really want more details, you can look here.

Jesus was a liberal hippie

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nwr
Member
Posts: 6408
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 5.1


Message 307 of 309 (597248)
12-20-2010 3:04 PM
Reply to: Message 306 by herebedragons
12-20-2010 11:01 AM


herebedragons writes:
So, I would like to ask you some questions about your point of view and to clarify your position on a few things.
I did post more about this at another site, during a period when I had been suspended at evcforum. Perhaps you might want to take a look at that.
I should add that usage of the other site has dropped to the point where I'm not at all sure that it's future existence is certain. So you might want to look while you can.
I should add that I am not a biologist. I do study human cognition and human learning, so my ideas on evolution partly reflect my looking at it as a learning system.
nwr writes:
You can account for the novelty by appealing to the biology. But if neodarwinism were a good model, then you should not have to keep appealing to the biology to help the model over its weak points.
herebedragons writes:
This is the first thing I am unclear on; what do you mean by "biology" in this context?
On rereading, I guess that was a little unclear.
Let me start with an analogy using physics. Suppose a critic of relativity were to say "relativity implies that x happens, but it doesn't." I would expect the physicists to respond with empirical data showing that it does happen, or with an argument showing that the critic has misunderstood the theory.
Now, instead, suppose that the critic says "y happens, but is not explained by the theory of relativity." Then, in that case, I would expect the physicist to reply with details of how the theory actually does explain it (or with an admission that the theory doesn't explain everything and this is outside what it is expected to explain). What I would not expect, would be for the physicist to respond with empirical evidence that y actually does happen. For that kind of evidence based reply would seem to be begging the question that was asked.
Back to biology. Behe raises the issue of the flagellum, and says that neo-Darwinism does not explain it. Most of the response that I have seen have been of the form of empirical evidence that the kind of structure Behe says is irreducibly complex actually does arise. Well that's the same kind of question begging. The answer should have been in form of the details as to how the theory shows that this kind of irreducible complexity can arise.
The problem, as I see it, is this: The neo-Darwinian account of evolution is a highly mechanistic account. Mechanism works pretty well for explanations in physics, but it does not work very well in biology. It seems to me that biology needs a notion of "purpose" in its explanations. There's currently an interesting discussion at John Wilkins' blog. Most of the discussion is in the comments, rather than in the original post. It is on the question of whether the language of teleology (purpose directed activity) is being inappropriately used in discussions of evolution. I think you would have to agree, from that discussion, that people find it hard to avoid teleological language. Some of the critics of evolution talk about "Darwinian fairy tales", as a way of expressing their cynicism about some of the teleological assumptions that seem to be implicit in a lot of neo-Darwinian explanation.
What I was trying to do in my alternative theory, was turn things upside down. The existing view is one that describes evolution as a mechanistic and purposeless reality acting on apparently helpless biological organisms, and shaping them for fitness. I wanted to reverse that, and have it a theory of biological organisms acting on themselves. That allows assumptions of purposeful (but not conscious) action, such as a population modifying itself so as to increase the chances that the population will persist in spite of changes to the environment.
herebedragons writes:
Organisms appear fully functional with novel features intact and operational.
I don't think that's particularly surprising, even on a neo-Darwinian account.
herebedragons writes:
An example is the Italian Wall Lizard that evolved a new and novel feature (the cecal valve) in about 30 generations from a founding population of 5 breeding pairs!
That's an interesting example. Thanks for the link.
herebedragons writes:
I have been unable to find any follow up work on this discovery that draws conclusions about how this novel feature actually evolved, but it seems unreasonable that this cecal valve evolved in gradual steps in such a short time. Instead, the cecal valve appears fully functional and operational.
You have to keep in mind that sexual reproduction involves recombinant DNA (combining DNA from both parents). It is quite possible that the genetic innovation required for this cecal valve was already present in the population, though only infrequently expressed in the phenotype (the observable traits). If the new trait was not particularly advantageous, then it might show up only occasionally in individuals. Once these lizards were moved to a new environment, it might have happened that the new trait was particularly beneficial there. So those with the new trait would expand their population, perhaps almost explosively, as they start to exploit a new niche for which they happen to be well suited. And, very quickly, that new trait would become dominant in the resulting population.
herebedragons writes:
You seem to advocate PE as a major factor in development of novel features.
I wouldn't put it that way. Rather, I see PE as an expected phenomenon. In the previous paragraph, I mentioned the almost explosive growth of a population that happened to be well suited to a new niche. And it is that kind of "almost explosive" growth that I would expect to show up as punctuated equilibrium. We need to distinguish between the genetics, and the expressed traits. We should expect the genetic changes to be gradual, but the change in expressed traits could be far more rapid in some circumstances.
herebedragons writes:
I believe that neo-darwinism has rejected PE in favor of gradualism or at least relegated it to a very minor role.
You hear less about it since the death of Stephen Gould. But it still has proponents. One of them is Larry Moran, who sometimes blogs about the role of contingency (as opposed to selection).
herebedragons writes:
What is not clear is how changes could accumulate in regions of the DNA that are not being expressed and therefore not being selected for.
They are not being selected for. But they are also not being negatively selected, which is why they can accumulate without selection pressure limiting them. But some of those genes can be transposed into coding parts of the DNA, so they could be a potential reservoir of variability.

Jesus was a liberal hippie

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