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Author
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Topic: A physics student's view of evolution (response to Barham)
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James A. Barham
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Member # 50
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posted 17. July 2002 08:07
Frances:
Far from clutching at straws, I am simply trying to make you see that you are begging the main question at issue---the tacit reliance of selection theory on teleological concepts. The ontological status of purpose in nature happens to be the topic of this web site. It is the very heart of the problem of biology (because purpose is an intrinsically biological phenomenon). This is not mere semantic quibbling, it is the essenc of the problem we are discussing here.
Erik:
If I recall correctly, you are the one who originally changed the subject to reductionism. (Not that I am complaining---to understand evolution properly, we must see it in the larger context of a general emergentist metaphysics, in my judgment.) But if you want to go back to discussing evolution, I am more than willing. This is your thread. Have at it.
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Frances
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Member # 169
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posted 17. July 2002 12:12
James. It fascinates me to still hear you make the claims that natural selection relies on teleological concepts. There is no 'purpose' involved in natural selection perse, it's that simple. That animals have developed instincts and behavior that help them 'survive' can be quite well understood through selection. So where is the 'tacit reliance of selection on teleology'?
quote:
As Ringen points out, the process of natural selection doesn't quite measure up as a teleological system. Selection itself can only filter, at best supporting the conditional: if the appropriate sort of variation is generated, it will be selected. The generation process that provides the candidates for sorting itself is deemed by orthodoxy to be unresponsive to appropriateness. So there can be no guarantee, or anything even close to a guarantee, of genuine "teleological" or meaning-tracking behavior in evolution. I agree, then, with the passage Ringen quotes from Lewontin (1979): "The dynamics of natural selection does not include foresight, and there is no theoretical principle that assures optimization as a consequence of selection."
From: Evolution, Teleology, Intentionality
Reply to Ringen and Bennett, (continuing commentary on "Précis of The Intentional Stance"), Behavioral and Brain Sciences, 16, (2), 289-391, 1993.
Daniel C. Dennett
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James A. Barham
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Member # 50
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posted 17. July 2002 12:42
Frances:
Maybe I should be clearer on the meaning that "teleology" has for me. You seem to be conflating the immanent and transcendent senses. I have tried to be very careful to indicate that I have in mind only the immanent sense, but since common usage tends to conflate them, perhaps I have not been careful enough.
I am not claiming that the evolutionary process as a whole is goal-directed in the sense of, say, Teilhard de Chardin, who claimed there was an "omega point" that acted as an external attractor dragging the whole process along. That is not my belief.
I am only claiming that selection theory implicitly relies on the immanent teleology in individual organisms in its explanatory structure. Therefore, natural selection cannot explain that immanent teleology.
As for the evolutionary process, I like to make an analogy with the structure or morphospace governing the complexification of the chemical elements over time in stellar nucleosynthesis. We do not say that there is an external attractor occupying the position of Element 79 that is pulling hydrogen toward gold. Rather, we say that due to the Pauli exclusion principle and other factors, there is a certain structure to the bottom-up, step-wise composition of the elements.
I suppose one could try to explain the periodic table by a "selection principle"---those variant atoms that just happen to "fit" with the Pauli exclusion principle will survive and be "selected" by nature. (Obviously, anything at all can be explained by "selection" in this sense.) But that would be an incredibly unenlightening and superficial view of what is going on. The process is not teleological, but neither is it just random. Rather, it is governed by natural law.
What I am saying is that the complexification of life forms over the course of the evolutionary process is analogous to the complexification of the chemical elements---it is not random, but structured. There is this difference, though. The nature of the internal dynamics that is responsible for the structure in the case of organisms is different. It goes beyond just QM. We must suppose that there is a sui generis purposive dynamics of the living state, because it is absurd from a physical point of view to imagine that the massive coherence and coordination of living things can be explained by chance.
But the analogy is useful to this extent. I am claiming that the evolutionary process should be viewed as structured and organized step-wise from the bottom up by the intrinsic or internal or "immanent" purposive dynamics of living matter, not pulled forward by some Teilhardian omega point.
[ 17 July 2002, 12:44: Message edited by: James A. Barham ]
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Frances
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Member # 169
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posted 18. July 2002 21:39
James,
I ran across an article of yours on iscid which helps me understand your argument and I hope it will help me explain to you why I believe it to be erroneous.
It's' Back to the stoics
I believe the relevant part is when you are taling about the assumptions of natural selection:
quote:
The most fundamental of these assumptions is that living things intelligently strive to achieve their goals.
But as I have shown this is NOT an assumption of natural selection although Darwin argues that such behavior can be explained by natural selection.
I believe that this assumption, which seems to be central to James's argument is fallacious.
Reading the paper I ran across another interesting, but imho fallacious claim, namely that "To show the vanishingly small
probability that even a single protein molecule can have arisen by chance, all we need are
ordinary physics and chemistry. The basic problem is that there is no energetically
favorable path leading to the immensely long polymers that constitute biomolecules. "
I would be interested in seeing some references to support this claim. Especially in the light of actual calculations
[ 18 July 2002, 21:42: Message edited by: Frances ]
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James A. Barham
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Member # 50
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posted 19. July 2002 08:37
Frances:
Obviously, I am not claiming that Darwinians expicitly or consciously presuppose teleology. I am claiming that they do so implicitly and inadvertently, and that this fact contradicts the claim that natural selection has somehow "explained" immanent teleology in nature. It has done no such thing.
Here is another analogy that occurred to me, in my struggle to communicate this concept to you.
Darwinians often claim that their theory does not really attribute adaptation to "chance," because natural selection acts as a "ratchet" to lock innovations in place. In this way, we can supposedly see how a gradual sequence of incremental steps can lead to complex adaptations, so that natural selection is supplying the order into the process, and the relative importance of chance is reduced.
But obviously this analogy begs the question of the structure of the ratchet!! After all, how does a ratchet work? It works by introducing certain physical constraints into a system that then bias the behavior of the system.
My claim is simply that the Darwinian evolutionary ratchet is taking for granted the physical constraints of organismal, purposive dynamics. It is this dynamics that is biasing everything, and therefore bearing the brunt of the explanatory weight. This seems like such a straightforward point, I have trouble understanding how you don't get it.
In fact, many Darwinians do get it. Ernst Mayr himelf, for example, freely admits this point. The usual fallback position is then to make a distinction between "proximate" and "ultimate" explanation, and to place the chore of naturalizing teleology on the "proximate" explanation. (In Mayr's case, he appeals to the "teleonomy" of genetic "programs." George C. Williams is another prominent evolutionary theorist who makes precisely the same move, with the emphasis on "information.")
I have been waiting and waiting for you to make this move, so that we can then go on to discuss whether molecular biology, cybernetic control theory, etc. can naturalize the immanent teleology of the cell. I have been rather surprised that we have not yet gotten to that point in our discussion. But that's okay. It is not a good fallback position for you, anyway. It is probably smarter, from the die-hard Darwinian point of view, to refuse to make the fatal concession that the explanatory logic of the theory of natural selection presupposes the functional integrity of the organism. Better to tough it out, than end up in a cul-de-sac . . .
On the other hand, I'm really not sure how productive it is to keep going over and over the same ground.
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Stephen Wright
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Member # 195
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posted 19. July 2002 12:29
Erik,
Thanks for providing the link to a prior discussion. I found the description of teleology by the authors of the book, Evolution (1977) consistent with what James and I suggest. They make the distinction between universal teleology from a local type (my term) or immanent type (James) by calling it internal. They then further try to make the case that some teleology is determinate and other cases are indeterminate. They conclude saying that there are “certain forms of teleology” that apply to evolutionary EXPLANATIONS and some that don’t. So, there is to be perceived this gradient and a seeming transition from one kind of realized purpose that drives our explanations, to another type that is inconsequential to explanations related to evolution.
However, they do not address a clean cutoff between these designations. Does internal teleology occur only when fully encoded in DNA? What percentage of specified determination is the cutoff? That there is a potential boundary between theories to be addressed is the exact issue that is addressed by Batterman, in Devil in the Details (2002).
Quoting from page 121 under heading of A New Sense of Emergence he states, “There is a new sense of the term “emergence” that is not captured explicitly by the five tenets already listed. But it is a sense of the term that better fits the status of phenomena which inhabit borderlands between theories.” As examples he uses the physics behind the appearance of the transitions of light in a rainbow and also events in fluid dynamics. He defines the asymptotic explanations that create a clearer picture than available when viewed with the reductive answers alone. This occurs when two or more viewpoints or theories are needed to define attributes of an event.
In my career, which involves the electro-chemical creation of conductive circuits, this way of thinking hits the nail on the head. The very, very simple oxidation/reduction reaction that fully describes the overall process of metallic ion transfer to a circuit board or silicon chip has a level of explanatory value. However, the ACTUAL process when subjected to a six-sigma process control analysis reveals that the interactions between variables are amazingly complex, when viewed at the diffusion boundary layers 1 micron from the anode and cathode. There exist many hundreds of patents that address the sub-reactions that occur there. I have a true appreciation for those process engineers who methodically identify parameter after parameter that goes into having the process yield its intended result. I also like the fact that right and wrong answers are in a feedback loop that proves theories right or wrong in hours or days, not decades.
In this world of industrial processes the idea of viewing the systemic steps and NOT nailing down ALL relevant variables, even those seen as inert in an overview, is unthinkable. How we can talk about biological adaptations and exclude the functional presence of will power (local or immanent or internal) of organisms is beyond me.
[ 19 July 2002, 13:20: Message edited by: newchurchguy ]
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Stephen Wright
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posted 19. July 2002 15:24
Frances,
I fully agree with Mr. Dennett that NS is not a teleological concept, and it is functionally a filter in the process of evolution. I surely see NS as a most effective variable among the systemic parameters involved with evolution. However, adaptations both physical and behavioral are locally purposeful and useful by definition. Organisms observing and responding to their environment generate them. Therefore the teleology is in the responses of organisms to their environment.
NS is one variable in the process. The ability of organisms to connect their intentional acts with potential sources of fulfillment is another, which is teleological in every sense of the word. Therefore, evolution has a variable that contains purposeful functions and others that do not. Once in the loop, goal directed behavior has its own consequences in the evolutionary process. I suggest that NS selects adaptations that have strong feed-back loops more readily than those that provide less information. This would favor the growth of purposeful behavior.
[ 19 July 2002, 15:29: Message edited by: newchurchguy ]
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