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Author
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Topic: Common descent
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New York Wiseguy
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Member # 210
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posted 24. April 2002 06:25
I'm being somewhat of a laggard here, but James, Paul and Drosera all had some very interesting things to say, to which I'd now like to respond.
To James A. Barham:
"your disagreement with Fry is largely verbal, rather than subtantive".
Yes, I'd agree, and I from Paul's initial paraphrase, I thought she was being teological, but I'd retract that since Paul has shown her original language.
"such an event would be "tantamount to an abrogation of the laws of nature," hence indistinguishable from a miracle. Would you agree with that?"
We're really getting into semantics here. I think for our purposes, however, a "true" miracle must be something grossly contrary to the "laws" of nature, like an object or living being appearing before our eyes "in a puff of smoke". A robin hatching from a dinosaur's egg might also qualify. But I'd have to agree that there could be events that are of such low probability that opinions might honestly differ as to whether or not they were "miracles". Take the 1969 Mets, as an example :-). But in all seriousness, yes, there would be a range of imaginable events across which there could be an honest difference of opinion among reasonable people whether or not the event was a miracle. We should also recognize that prior to 400 years ago and the rise of modern science, many events were commonly understood to be miracles. For some time now, however, there have been no observed events which have been widely accepted to have been miracles. So what we are discussing is whether miracles may have happened in the past -- the very distant past.
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To Paul:
I appreciate your candor, and think perhaps we could agree about what it is we're disagreeing. You say "When I lay aside the constraint of methodological naturalism", which goes a long way toward clarifying for me your line of reasoning. Now I'd like to ask you this: How do you categorize knowledge that is gained by the laying aside of methodological naturalism? I. e., do you consider such knowledge to be "scientific knowledge"?
"Darwin's single Tree of Life is not long for this world"
Even if we acknowledge that it perhaps looks less like an oak than it does a mangrove?
"I still need to say something about the consequences for higher-level polyphyly."
That's of considerable importance, as I would be inclined to say Darwin's tree remains quite valid for the "recent" history of life. I. e. once the history gets clear of the uncertainties of the Cambrian explosion.
"Funny, NYWG, that you should mention 1,000 steps in the abiogenesis story."
What can I say, "All great minds..."? I almost said a million, but then thought that would be too extravagent.
"the need for very good odds indeed at each step"
Now I'm not so sure. If we think polyphyly, the odds weren't necessarily that small. I wonder if Monod might not have been too quick to dismiss "necessity". If most of those 1,000 steps are polyphyletic, DNA and procaryotes could have assembled themselves in gradual stages and survived with the appearance of common descent simply becase that was the only form that could continue to evolve. And 2 billion years is a long time.
Paul, you hypothesized a time machine to look ahead 1,000 years. Suppose we talk about a time machine that allows us to look back upwards of 4 billion years, and suppose, further, that this machine can function as a spacial-temporal 3 dimension Xerox machine, so we could capture samples of all matter as it existed at a given place and time in a chamber of a given size (the largest models could even capture whole dinosaurs). (I say it's a Xerox machine because it couldn't remove matter or we run into the classic time travel paradox. It only copies matter. I know, I know, we have to suspend the operation of the Heisenberg uncertainty principle to get it to work.) With this research tool, given enough time and patience, we could figure it all out. This, now, is an extension of the conversation that was going on in Evan's topic "Defining the issues." What would we see happening?
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To Drosera:
You put your finger on it by asking what is the definition of "ancestor". Working our way backwards in time, we don't expect to find "common descent from a single ancestor" in microevolution, nor in the "lower" levels of macroevolution, which for some includes speciation. We assume populations have evolved, with a shift in the distribution of certain attributes from generation to generation. So, as you and others obviously feel, polyphyly does not necessarily negate the Darwinian tree until we get way, way back in time, perhaps all the way to abiogenesis.
And, Drosera, I like your introduction of the notion that we should define some words. I've been wondering if we have enough understanding of what is meant by "biological information". I see a problem in that we, at this stage in molecular biology, know a lot about genes, and gene mapping, to where we can virtually, in effect, make a fully detailed drawing of all the atomic parts of a strand of DNA. But despite that capability, we don't know much at all about how the DNA "works" to fabricate the living organism that will reach maturity. We can connect some genes to some attributes of the organism, but that's empirical knowledge, and we still don't know the mechanism by which it happens. I'd suggest that this is a distinct handicap to the use of complexity and information theory to analyze biological processes.
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Paul A. Nelson
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posted 24. April 2002 10:01
Just saw this abstract. Haven't seen the paper yet. Note especially the last sentence in the abstract.
Recent emergence of the modern genetic code: a proposal [Opinion]
Michael Syvanen
Trends in Genetics, 2002, 18:5:245-248
Abstract
This article proposes that the genetic code was not fully formed before the divergence of life into three kingdoms. Rather, at least arginine and tryptophan evolved after the diversification of archaea, bacteria and eukaryotes, and were spread by horizontal gene transfer. Evidence for this hypothesis is based on data suggesting that enzymes for biosynthesis of arginine and tryptophan, and for arginine tRNA ligase, have shorter divergence times than the underlying lineages. Also, many of these genes display 'star' phylogenies. This proposal is an extension of the idea that the genetic code was unified because of the evolutionary pressure from horizontal gene transfer. These considerations further undermine the need to postulate the existence of a 'last common ancestor'; a simpler model would be that multiple lineages gave rise to life today.
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Janitor@MIT
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posted 24. April 2002 15:08
Traveling backwards in time is an intriguing sort of science fiction. But what we would require is not a machine that removes us to any instant, but one that moves freely forward and backward over infinitesimal increments in evolutionary time. (A time dilation machine!)
Phylogeny certainly represents a considerable problem in pattern recognition, but my concern is what is the process that leaves the pattern we observe? What kind of level of confidence can we possibly have in inferring the process from the pattern in this (special?) case?—assuming that the process in its details cannot be captured in experimental time, but only in evolutionary time (which is inaccessible to us).
I think (but I’m not sure) that Paul Nelson has considered the kinds of “epistemological” questions that must naturally occur when we base any kind of “scientific” explanation on our understanding of events that are inaccessible to usual scientific, experimental, observational methods. (I realize that some researchers would resent my distinction between science as systematics and science as experimentation. No, I don’t believe phylogeny is equivalent to philately, but…)
In so many words, lacking a process model, can such a model be abstracted from patterns alone? (I.e., without a direct causative correlation, which “historians” usually argue endlessly over, because they have no time machine.) Is there any way I can make a confident scientific appraisal of the merits of monophyly or polyphyly? Or does it ultimately come down to a “Whig interpretation of natural history”? Is there a sort of “covering law” model of evolution at work here?
I think I remember reading somewhere (Niles Eldredge? Sorry for being so unprofessional.) that the paleontologists (molecular or otherwise) were complaining about the lack of a biological model for the patterns they detect and waiting patiently for the biologists to give it to them; while the biologists were telling the antiquarians that they had the best model they were going to get and to deal with it. Does that sound familiar? (If not, strike.)
I guess the real question is, pardon my bluntness, But is it science?
(I don’t want to distract from the topic, since I seem to be concerned with a tangent here. So I’ll leave the inclusion of this post, as usual, completely to the discretion of the Mr. Moderator.)
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James A. Barham
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posted 24. April 2002 16:26
NYWG:
You allowed that an organism suddenly popping into existence "in a puff of smoke" would count as a miracle. But that is precisely what the standard Darwinian reliance on chance asks us to believe in, both at the origin of life, and at every adaptive step forward thereafter. This is what Dembski rightly calls the "chance of the gaps."
Granted, one may quibble about the precise point at which improbable events become so improbable that they are "tantamount to a miracle," as I put it. But the quantitative work has been done many times with respect to proteins (e.g., by Murray Eden, E. Schoffeniels, Walter Elsasser, Howard Yockey, Fred Hoyle, and others), and whatever the cut-off is, it is certainly far below the threshold of a single protein, not to speak of whole cells. Hoyle's famous image of the 747 built by a tornado out of a junkyard illustrates the point quite well enough.
So, what does this mean? I believe it simply means that "chance" plays a relatively minor role (but not no role at all), both in the origin of life and in evolution. That is, I believe that the only explanation for these phenomena is that there are lawlike regularities through which some form of final causation is manifested.
If that is true, then clearly the origin of life may well have occurred more than once. So, while monophyly is perhaps crucial to the Darwinian scenario (since even one such spontanteous creation is hard enough to swallow), for the self-organization theorist it is not crucial at all. Indeed, from my point of view, polyphyly is probably the expected scenario.
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John Bracht
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posted 24. April 2002 19:30
Paul, James, others,
I have been following this thread with great interest. I just came across a source that seems very relevant to this discussion. His name is Christian Schwabe, and he holds a self-organizational, genetic-deterministic, polyphyletic view of the origins and development of life. Basically, he seems to think that all the information in living things was produced in the primordial soup and multiple lineages emerged which underwent a period of internally shuffling and mixing that genetic information, and altering the control sequences. Eventually, those lineages built up enough "genetic potential" that they blossomed into multicellular organismal lineages. Thus, most multicellular organisms, in his view, represent distinct single-cellular lineages that do not join together as we trace them back to the origin(s) of life. Here's a short online article by him:
http://www2.prestel.co.uk/littleton/schwabe.htm
Here's a short excerpt:
quote:
It seems far more likely that the transition was not A (single) to B (multi) followed by divergence of the offspring of B but rather (A1,A2,A3,---An) single cells transformed to (B1,B2,B3---Bn) multicellular organisms (Fig. 6). Although the fossil record is unmistakable on this point the lack of intermediates is notably not seen [by neoDarwinists] as evidence for the multiple origins scenario but rather as proof for the incompleteness of the fossil record.
I find his ideas absolutely fascinating and truly novel to think about. Paul, are you more familiar with his work?
John Bracht
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Paul A. Nelson
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posted 24. April 2002 22:19
John,
As an undergraduate, I began reading Schwabe's work on anomalies in the distribution of the hormone relaxin, and then moved on to his discussions of the historical topology of life. In the past few years, however, I've been mainly influenced by his arguments about determinism and the origin of life.
Another scientist to add to my "Brainstorms" contributor wish-list!
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Drosera
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Member # 139
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posted 24. April 2002 23:23
This kind of paper indicates what I'm talking about regarding lateral gene transfer probably not being the kind of crisis that Paul Nelson, or even W.F. Doolittle, might think in their more excited moments.
quote:
Mol Biol Evol 2002 May;19(5):631-9
Archaeal phylogeny based on ribosomal proteins.
Matte-Tailliez O, Brochier C, Forterre P, Philippe H.
Institut de Genetique et Microbiologie, Universite Paris-Sud, Orsay, France. Phylogenie, Bioinformatique et Genome, Universite Pierre et Marie Curie, Paris, France.
Until recently, phylogenetic analyses of Archaea have mainly been based on ribosomal RNA (rRNA) sequence comparisons, leading to the distinction of the two major archaeal phyla: the Euryarchaeota and the Crenarchaeota. Here, thanks to the recent sequencing of several archaeal genomes, we have constructed a phylogeny based on the fusion of the sequences of the 53 ribosomal proteins present in most of the archaeal species. This phylogeny was remarkably congruent with the rRNA phylogeny, suggesting that both reflected the actual phylogeny of the domain Archaea even if some nodes remained unresolved. In both cases, the branches leading to hyperthermophilic species were short, suggesting that the evolutionary rate of their genes has been slowed down by structural constraints related to environmental adaptation. In addition, to estimate the impact of lateral gene transfer (LGT) on our tree reconstruction, we used a new method that revealed that 8 genes out of the 53 ribosomal proteins used in our study were likely affected by LGT. This strongly suggested that a core of 45 nontransferred ribosomal protein genes existed in Archaea that can be tentatively used to infer the phylogeny of this domain. Interestingly, the tree obtained using only the eight ribosomal proteins likely affected by LGT was not very different from the consensus tree, indicating that LGT mainly brought random phylogenetic noise. The major difference involves organisms living in similar environments, suggesting that LGTs are mainly directed by the physical proximity of the organisms rather than by their phylogenetic proximity.
(Note that this is a little different than I implied before, Matte-Tailliez cite physical proximity as a more important factor determining LGT than phylogenetic proximity as I implied. I still think that phylogenetic proximity has to play a role, a role which will probably depend on the sensitivity of the organism in question to changes in its genes. A single new metabolic gene may by chance be helpful to some auxilliary process and may have a high liklihood of LGT to just about any organism. Highly regulated multigene complexes, core function genes, etc., might only be effectively transferable between organisms that start with very similar genomes.
In any case: the fundamental point is that LGT is not a free for all, there are patterns, and therefore there is a good chance that the "noise" they cause can be identified, just like scientists identify noise in pretty much every field where measurements are taken.)
No one asked, but if you want my bet on what tree is actually "not long for this world", as Paul Nelson put it, it is the Woese 'three domain model' of eubacteria, Archaea, and eukaryotes, e.g. that apparently used by the paper that Paul cited. This tree was originally based on rRNA sequences, which were relatively easy to obtain for a large number of organisms. They have proven very useful for figuring out relationships "within" domains, e.g. in the Matte-Tailliez et al. article I cited, but there is a good chance that the apparent early splitting-off of Archaea and eukaryotes is one big long-branch attraction artefact and that these groups are fairly derived.
Matte-Tailliez et al. note thermophily (adaptation to temperature) can effect the rate of sequence change. I think what they're saying above is that if the temperature constraints are tight, then sequence changes will also be constrained & sequences will change slowly.
Conversely, however, if an organism adapts from "cold" temperatures (such as seawater) to ultrahot temperatures (e.g. some archaea live in hydrothermal vents at temperatures over 100 C), then we could expect that adaptation to effect a great deal of the sequences (rRNA, DNA, and protein), as the sequences undergo directional selection for increased stability and proper folding at these high temperatures. This would result in a period of very rapid sequence evolution, a "long branch artefact".
Notably this scenario fits to a tee what could have happened to the Archaea, many of which have adapted to temperature niches which eubacteria have never reached. And further, if as many think eukaryotes are most closely related to the Archaea (actually we should be changing their name back to archaebacteria on this model), then we might have a situation where the common ancestor of Archaea and eukaryotes developed a novel form of flexible membrane and primitive cytoskeleton as an adaption to hyperthermophily; the Archaea stayed in these kinds of extremophile environments, while the eukaryotes reverted to mesophily as their flexible membranes and cytoskeleton preadapted them to exploit the niche of phagocytosis (eating) the hapless prokaryotes of the world. This second radical change in temperature would result in another rapid set of sequence changes and another long branch for eukaryotes.
Time will tell if this kind of scenario holds up, but it does imply that a literal interpretation of the three distinct domains on the Woesian rRNA trees may not be the best interpretation.
Drosera
PS: Notably the above observations also rather badly undercut the "hot origin of life" model which is based on the grouping of thermophiles at the base of rRNA trees -- again these may be long-branch artefacts due to adaptation to a temperature niche.
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Paul A. Nelson
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posted 25. April 2002 05:01
Hello NYWG,
Some quick replies (because of pressing business) to your various questions:
quote:
You say "When I lay aside the constraint of methodological naturalism", which goes a long way toward clarifying for me your line of reasoning. Now I'd like to ask you this: How do you categorize knowledge that is gained by the laying aside of methodological naturalism? I. e., do you consider such knowledge to be "scientific knowledge"?
Yes. I don't know how much space we should give to this topic here -- the moderator likes to keep threads focused. But briefly: I don't see human agency (for instance) as reducible to physical regularities or chance. Nor do you, I'd bet. Causes described by proper nouns -- "Paul Nelson," "John Bracht," etc. -- are nevertheless real, and leave distinctive and empirically detectable traces of their activity. Nothing spooky or mysterious. Just the recognition that intelligent causation is irreducible to physical regularities or chance processes.
It's as certain as any finding of physics that the posts here of "New York Wiseguy" are not the product of radioactive decay (or whatever).
quote:
"Darwin's single Tree of Life is not long for this world"
Even if we acknowledge that it perhaps looks less like an oak than it does a mangrove?
(An aside: I think there are limits on what the "tree" metaphor can carry, and still be biologically accurate.) My hunch about a dim future for the theory of common descent stems from watching the growing chaos in the literature on homology, both at the molecular and higher levels. Again, this is something I'll have to say more about later.
quote:
"I still need to say something about the consequences for higher-level polyphyly."
That's of considerable importance, as I would be inclined to say Darwin's tree remains quite valid for the "recent" history of life. I. e. once the history gets clear of the uncertainties of the Cambrian explosion.
If polyphyly exists at the Cambrian Explosion, that's not a tree. That's a forest.
quote:
"the need for very good odds indeed at each step"
Now I'm not so sure. If we think polyphyly, the odds weren't necessarily that small. I wonder if Monod might not have been too quick to dismiss "necessity". If most of those 1,000 steps are polyphyletic, DNA and procaryotes could have assembled themselves in gradual stages and survived with the appearance of common descent simply becase that was the only form that could continue to evolve. And 2 billion years is a long time.
Christian de Duve was referring to the origin of the first cell(s). His 1,000 steps include such events as encapsulation, the origin of metabolism, the origin of information storage and transfer, the origin of selective transport, and so on. Assign even odds (50% chance of success) to each of these steps, and -- if the events are independent -- one soon faces very daunting probabilities indeed.
quote:
Paul, you hypothesized a time machine to look ahead 1,000 years. Suppose we talk about a time machine that allows us to look back upwards of 4 billion years, and suppose, further, that this machine can function as a spacial-temporal 3 dimension Xerox machine, so we could capture samples of all matter as it existed at a given place and time in a chamber of a given size (the largest models could even capture whole dinosaurs). (I say it's a Xerox machine because it couldn't remove matter or we run into the classic time travel paradox. It only copies matter. I know, I know, we have to suspend the operation of the Heisenberg uncertainty principle to get it to work.) With this research tool, given enough time and patience, we could figure it all out. This, now, is an extension of the conversation that was going on in Evan's topic "Defining the issues." What would we see happening?
Are you asking me with my methodological naturalism baseball cap on, or with my (much more comfortable) design theorist cap on? ![[Wink]](wink.gif)
[ 25 April 2002, 05:04: Message edited by: Paul A. Nelson ]
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New York Wiseguy
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posted 25. April 2002 06:29
This topic is moving too fast for me. Paul's last post crossed within the hour or so since I started composing the following. So I'll follow this with a response for Paul.
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To Janitor:
"a machine that removes us to any instant, but one that moves freely forward and backward over infinitesimal increments in evolutionary time."
Not to quibble about words, but that's what I mean by "instant". The time resolution of the device would actually need to be the quantum time increment (I believe there is such a thing, but I don't recall its magnitude).
"I think (but I’m not sure) that Paul Nelson has considered the kinds of "epistemological" questions that must naturally occur when we base any kind of "scientific" explanation on our understanding of events that are inaccessible to usual scientific, experimental, observational methods."
I would hope he would tell us. Otherwise we might be talking past one another, if we are not using a common language.
"...pardon my bluntness, But is it science?"
I'm glad you said that. My question precisely.
And, I'd further suggest that our differing views are based upon our respective personal senses of what we believe are the most plausible explanations for the scientifically inaccessible events. I would also suggest that the imaginary time machine as a research tool for observing the past down to the particle level is useful as a device for discussion. In that I would suggest that anyone expressing an opinion on these matters ought to feel obligated to state his/her opinion as to the most plausible conjecture as to what would be observed if we had the use of such a machine.
To James A. Barham:
"in a puff of smoke" ... "But that is precisely what the standard Darwinian reliance on chance asks us to believe in, both at the origin of life, and at every adaptive step forward thereafter."
I'm not sure I see what you are driving at here. I could quibble that Darwin really had nothing to say about the origin of life, so we shouldn't "blame" Charles himself for what has been said in his name on that question. But, talking about the "adaptive steps", and "one may quibble about the precise point", we can recognize that there is a rather large gray area between Hoyle's "747 out of a junkyard" and a radiation-induced mutation. We need to recognise the philosophical impact of quantum mechanics. I don't think we should say every radiation-induced mutation is a "miracle". But, if we are discussing this with a person who believes there is an intelligence working behind the scenes calling the shots for every radation-induced mutation, there is no way we can, using the tools of science, prove that he/she's wrong. It gets back to what are our respective opinions as to which explanation is the more plausible.
"Indeed, from my point of view, polyphyly is probably the expected scenario."
I'm very inclined to agree, although, as I've said previously, applicable only to the earlier stages of the history of life. Not necessarily applicable, for example, to any of the stages of life's history that Mr. Darwin himself ever actually thought about.
In a previous post, Paul Nelson said: "I don't think that life arose naturally even once", and this tells us about his own personal sense of plausibility. It appears to me that the work of Schwabe and Matte-Tailliez lends some comfort to those of us who might have a different personal sense of plausibility. The details of rRNA phylogeny as discussed by Matte-Tailliez are completely over my head, but I do believe I have a good sense of their broad-brush-stroke implications.
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New York Wiseguy
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posted 25. April 2002 07:52
To Paul:
""do you consider such knowledge to be "scientific knowledge"?"----------
Yes. I don't know how much space we should give to this topic here"
I read you. I was contemplating starting a new topic called "Philosophical Underpinnings". I'll continue here until the moderator boots us out. I feel it might be valid to say we're still on topic, in that we are in search of a common language with which to continue the discussion.
"I don't see human agency (for instance) as reducible to physical regularities or chance. Nor do you, I'd bet......."
It appears to me you have gone into a digression here, wandering into social psychology. But we could continue on that theme. What is "science"? If we seek a definition in pragmatic terms, it is an activity practiced by a community of persons who have had the requisite education to hold day jobs in which they are classified as "scientists". Now then, I will maintain that if a poll were taken among that total population, a very substantial majority would agree with the statement "Science requires following the rules of methodological naturalism." Therefore, I will suggest that if we are going to have a discussion in which we lay aside methodological naturalism, we should apply some adjective to it other than "scientific".
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""What would we see happening?"---------
Are you asking me with my methodological naturalism baseball cap on, or with my (much more comfortable) design theorist cap on?"
Well, let's see, I'm asking what we would "see". OK, I'll ask that you leave your more comfortable design theorist cap on. I'll say some more about what the 3-dimensional spatial-temporal Xerox machine can do. It captures in a chamber a rectangular parallelopiped of the matter in a space from a given location at a given instant of time, and it can give us two successive samples separated by the smallest quantum time interval. We can then perform on as many samples as we wish all possible experiments using the tools of physics and chemistry. It is assumed, likewise, that we can make a "drawing" of the position and identification of every particle in the chamber. We have the expectation of observing a certain number of discontinuties from one quantum time interval to the next, caused by photons here and there randomly trigerring changes in state at the atomic level. The question now becomes: if "design" is being manifested, how would it reveal itself? The most gross sort of discontinuity we might imagine between two successive observations could be the abrupt appearance, or instantaneous change in composition, of a block of matter consisting of several billion particles. Lower down on the scale could be several billion adjacent atoms being simultaneously struck by photons causing a state change. On the other hand, "design" could also manifest itself in such a subtle way, by merely a slight shift in probabilities, that it might be ambiguous to us whether it has actually occurred or not. Am I proposing alternative scenarios which are relevant to the question? Would you care to indicate a choice as to which conjecture appears to you the more plausible?
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Paul A. Nelson
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posted 25. April 2002 12:08
NYWG wrote:
quote:
I will maintain that if a poll were taken among that total population, a very substantial majority would agree with the statement "Science requires following the rules of methodological naturalism." Therefore, I will suggest that if we are going to have a discussion in which we lay aside methodological naturalism, we should apply some adjective to it other than "scientific".
As you like. Pick the adjective or noun that suits you; it doesn't matter to me. The naming of things does not affect the things themselves. (A rose by any other name, et cetera...) Our subject matter won't change.
[ 25 April 2002, 12:10: Message edited by: Paul A. Nelson ]
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James A. Barham
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posted 25. April 2002 19:10
NYWG:
My point about the adaptive steps being similar in improbability to the origin of life has nothing to do with individual mutations, which are obviously not all that improbable. It has to do with the improbability of such chance events becoming appropriately coordinated, and ever adding up to novel, functionally integrated structures or processes.
The odds of this happening without some sort of internal guidance are just as astronomical as the odds on the origin of life. As I see it, this is really Michael Behe's main point. I think there is a lot of misunderstanding on this issue. Behe is saying (or so it seems to me) that on the Darwinians' own assumption of "chance" mutations, then it is inconceivable that complex adaptations can occur. The point is not that there aren't relatively smooth transitions in between forms, either extant or at least imaginable, but rather the point is that no such transitions are to be expected on the basis of purely "chance" mutations alone. The probabilities are just astronomically against it even one time, much less the billions of times Darwinians suppose it has occurred throughout the course of evolution.
The Darwinians are constantly tacitly assuming the background of the functionally integrated intelligent agency of the cell, without which evolution makes no sense. Which is fine by me, except that then they cannot turn around and pretend that they have "explained" evolution without recourse to teleology!
BTW, I have no quarrel with Charles himself. He was a great man---for his time. But he did live a long time ago. The hero worship of Darwin is simply grotesque. Can you imagine a physicist going on about Newton the way people go on about Darwin? He would be laughed out of the laboratory. The difference, of course, is that biology is only now struggling to become a true theoretical science, as opposed to a massive body of empirical data that we do not really understand. If and when the transition to an authentic theoretical biology occurs, then the historical Darwin will finally be allowed to recede into the history of science, where he belongs---along with all the other great scientists of the past.
[ 25 April 2002, 19:11: Message edited by: James A. Barham ]
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New York Wiseguy
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posted 26. April 2002 07:24
To Paul:
"Pick the adjective or noun that suits you"----
I'll pick "metascience" and will look forward to reading more metascientific discussion.
To James A. Barham:
"The point is not that there aren't relatively smooth transitions in between forms...."====
Are you saying there are not in fact relatively smooth transitions between some forms? I. e., that if we could observe the appearance of a new form, we would see something undoubtedly not in accordance with natural law? I injected "some forms", because I mean to ask whether, at any level (such as phyla), you believe there to have been a non-smooth transition between forms.
"The hero worship of Darwin is simply grotesque."
I haven't particularly been conscious of any excessive hero worship. Oh, here and there, in defense of evolution, one might see someone lionizing Darwin, but it there isn't any impulse to do that for Newton because no one attacks Newtonian physics in the same terms with which Darwinian evolution is attacked. For myself, I consider the two of equal stature, and far above any other contributor to scientific knowledge.
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James A. Barham
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posted 26. April 2002 10:37
NYWG:
No, on the contrary, I meant to say that I DO believe that there are relatively smooth transitions between all adaptive forms (obviously, "relatively" is a weasel-word, but the "smoothness" will have to ultimately be judged in relation to the dynamics, which we do not yet know---i.e., we really have no idea how speciation works at the genetic level).
I am simply saying that Behe is best understood, not as denying smooth transitions between states (many of which have already been identified, after all, as with vision), but as denying that "chance" can explain ANY adaptational advance, because too many things have to happen together in a coordinated fashion for it to be plausible that ANY adaptation could ever occur by "chance."
As for Newton, I rather think there was a spot of bother back 100 years ago or so, when a few folks were indeed "attacking" him: Einstein, Planck, Bohr, Heisenberg, Schrodinger, de Broglie, Dirac, to name a few. What I am saying is that biology may finally be ready for its quantum revolution, which will relegate Darwin to the history books where he belongs.
[ 26 April 2002, 10:40: Message edited by: James A. Barham ]
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New York Wiseguy
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posted 28. April 2002 09:12
To James A. Barham:
I understand your position more clearly now, but there remain some questions.
"we really have no idea how speciation works at the genetic level"
I do not see in what way that is such a deep mystery. Speciation, by definition, has occurred when two forms diverge from an original form to such an extent that they can no longer interbreed. We see evidence that speciation can be a gradual process by examples of two species which produce mule offspring, the most well-known being the horse and the donkey. The term "mule" is also applied to the offspring of other specie-pairs where the speciation process is not fully complete. A more complete speciation has occurred between the dog and the wolf, where crossbreeding does not necessarily produce mules, but does usually produce unstable and/or defective offspring.
"Behe....denying that "chance" can explain ANY adaptational advance"
I have not understood Behe as taking that strong a position. I interpret Behe as saying that certain advances are so dramatic (the bacterial flagella being one favorite) that they cannot be explained by a series of random events. Those who disagree with him can point to some structures in other species which appear to have represented intermediate stages in any such adaptation, but his critics admittedly cannot find examples of all the required intermediate steps.
It should be pointed out that "chance" is not the only factor which results in adaptations. Chance only causes variations, and then some sort of selection process takes place in which the more favorable variation has a greater probability of survival. The debate is over two issues (1) Whether chance causes a sufficiently rich pool of variations on which a selection process can operate and (2) Whether the selection process can operate fast enough to produce the total change which is observed within a give span of time.
What is happening these days is that variations are coming to be recognized as caused by more phenomena other than radiation-induced mutations, such as horizontal gene transfer. And the selection process might be enhanced by other means than Darwin's classical "natural selection".
"Newton....when a few folks were indeed "attacking" him..."
Darwin, however, was attacked vigorously during his onw lifetime, which I do not believe happened to Newton. Also, while I'm not familiar with the literature of the time, I don't believe any of the names you cite "attacked" Newton as having been "wrong". My understanding is that it was generally recognized that Newton's laws, while valid over distances and speeds at which the speed of light did not come significantly into play, broke down beyond that domain. I believe there is a very exact parallel between the manner in which Newton was overrode and Darwin is now being overrode.
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