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Author
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Topic: Elliott Sober's Independent Evidence Requirement for Design
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Jack Foster
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Member # 79
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posted 25. October 2002 21:06
quote:
I wonder what you consider the relevant hypotheses to be. 1) The person is lying about jumping that high 2) the person did jump that high ?
This is correct, and these two hypotheses are exhaustive. If we conclude that it is extremely improbable to the point of impossibility that the person could have jumped that high, then we conclude that the person is lying about jumping that high. Indeed, that is the logical conclusion.
The same is true about origins (for instance). If we conclude that the chance origin of life is extremely improbable to the point of impossibility, then we also can conclude design. Chance and design, together, . . . are exhaustive. Sober doesn't seem to recognise this.
(I'm going out for the evening. I thought I could at least clarify the reasoning behind my analogy before I head out! Ta ta!)
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Jack Foster
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posted 26. October 2002 03:50
Hi Frances:
Posting new material in old posts is a bit confusing, Frances. I presume that you did that to comply with the three post rule, but I don't think the rule was designed to confuse people! Better to break the rule, in my opinion; or wait for a few hours to pass before responding.
At any rate, I'm not sure I should continue with the conversation. I don't think we're really speaking the same language, and for that I take responsibility. I was a music major in school! I have no background in this, but I'm interested nonetheless. Perhaps it's unfair to ask you to talk in layman's terms and to use the English language to the extent possible. I believe I have a grasp of what Sober is saying, but quite frankly I may be mistaken, because what I think he's saying just doesn't make sense to me.
It seems to me that Sober wants chance hypotheses to compete directly with design hypotheses. So to explain phenomenon P, we have HC1 (first chance hypothesis), and HC2, and HC3, and maybe HC4 and HC5, and so on; competing with each other and with perhaps HD1 (first design hypothesis), and HD2, etc. We calculate probabilities (priors and posteriors!) and do some likelihood analyses on each, throw the data into some hopper, and out pops our best explanation. Design hypotheses compete head to head with chance hypotheses, and are not fundamentally differentiated from each other.
This does not give recognition to the fact that design explanations must be placed in a different category than chance explanations. As Philip Page has said, they are different modes of explanation. Given some assumptions we can calculate the probability of some phrase, for instance -- say "Now is the time for all good men to come to the aid of their country" -- under a chance hypothesis (27 ^ 68). How do we calculate the probability under a design hypothesis? Well once the phrase was in my head, and I started to type it, it became 1. But I might have leaped to "The quick brown fox . . . " instead. Or "methinks . . ." Design likelihoods, prior probabilities, and posterior probabilities, are necessarily ambiguous under design hypotheses. Yet Sober (I think) wants to have the apples compete directly with the oranges.
You say that I'm confusing "chance and design as logical opposites, and probabilistic opposites". I don't know what you mean. Chance and design are logical complements. That's what I mean when I say they are exhaustive. If something happened by chance, then it did not happen by design, and vice-versa. And if something had a 50% likelihood of happening by chance, then it also had a 50% likelihood of happpening by design.
So now let's go back to HC1, HC2, HC3, vs. HD1, HD2, etc. If I take a broad look, there is no HC1, HC2, HC3 -- there is only HC. (I'm explaining how I see it.) This is particularly true in regards to an explanation for life. Because chance didn't have a prayer of explaining life until its champion -- natural selection -- was found. Natural Selection is THE chance hypothesis. Truly, it is the only reasonable non-interventionist explanation that exists.
Design, on the other hand, has a wide variety of potential hypotheses that might get into the game. But detailed explanations aren't important at this point (and actually only serve to get us well beyond the evidence); they can be lumped into one category when competing against HC; let's group them and call the group the design hypothesis, HD.
NOW they can be placed in competition, because HC and HD are logical complements. If we show that HC -- Natural Selection -- is irrational as explanation for some phenomenon, then design is the logical conclusion. I may not have the background of others, but this conclusion seems indisputable to me.
I'll recognise my general ignorance at this point, and bow out unless invited back in. I would not mind input from the moderator, either on the thread or in private communication as to whether or not I should continue participating in this type of thread.
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warren_bergerson
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posted 26. October 2002 04:41
Quote Frances: The same should be true for origins. If we conclude that natural selection is simply not a sufficient force to accomplish life, then design should be implicated. This seems clear to me. As likelihood of chance is reduced to nil, likelihood of alternatives increase to 1.
Quote Jack: NOW they can be placed in competition, because HC and HD are logical complements. If we show that HC -- Natural Selection -- is irrational as explanation for some phenomenon, then design is the logical conclusion. I may not have the background of others, but this conclusion seems indisputable to me.
Because two individuals from different back grounds are both convinced that the only two possible explanations for life or the origins of life are ‘chance or design(by a designer)’ or ‘Darwin or God’, does not mean the dichotomy is real. There is at the very least a third ‘deterministic option’. The possibility clearly exists that the origin of life, and the ongoing changes to life forms can be explained by some as yet unidentified deterministic/materialistic processes.
A major part of the problem in attempting to evaluate possible explanations is that concepts such as HC and HD are so poorly defined. People imply that terms like ‘HC-Natural Selection’ have precise definitions, but can not produce such a definition and won’t accept any explicitly formulated definition offered.
It can reasonably be argued that the ‘life from the miracle of chance’ hypothesis and the ‘life from a miracle by a designer’ hypothesis are logically the same. It can also be argued that neither chance nor design by a designer constitute legitimate scientific explanations or hypothesis.
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Jack Foster
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posted 26. October 2002 12:34
Hi Warren:
You quoted ME twice! I said what you thought Frances said.
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Mark Szlazak
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posted 26. October 2002 13:55
I haven't read Sober's paper but it seems to me that if you have two mutually exclusive hypothesis and the probability of one is extremely small (virtually zero) then the rational choice is it's compliment. Of course this doesn't imply that all the data is therefore explained by the compliment, just the one(s) under consideration.
Now if this is the case, then evolutionary data can be explained by 1) chance plus physical regularity and 2) design. Actually, Sober admits this possibility already with his belief that humans will reach a point when they too can design and build life from scratch. Here is maybe another "rub" for the Darwanian falsificationist since we don't anymore have a universal hypothesis about the explanation for evolution.
Instead we have singular-type claims and isn't it the case that the doctrine of Falsificationism is considered to be a failure for these types of hypothesis.
Just as an added note, there is a disconnect between causation and explanation when dealing with indeterministic situations. In the modern world this indeterminism is not just epistemic but ontological (i.e., anything BUT or BEYOND classical Laplacian determinism/mechanism). So in an indeterministic universe, one has causation where conditions are necessary but not sufficient, or sufficient but not necessary, and for classically deductive type explanations (especially singular events) both necessary and sufficient causes are required. Explanation in the classical sense is unattainable and Falsificationism in it's true sense can't deal with these situations. One could say that Falsificationism is suitable for "Victorian Science" and not really for modern science, but even in the outdated science this doctrine isn't adequate. It has a place but not when empirical data are involved, that place is abstract mathematics.
[ 26. October 2002, 18:24: Message edited by: Mark Szlazak ]
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Jack
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posted 26. October 2002 15:42
I too must confess to being confused by Sober's argument. Is he saying that a purely chance hypothesis is better than an ID hypothesis when it comes to explaining the origin of complex things like molecular machines? In my opinion, what makes Darwinian evolution plausible in the minds of most persons is its gradualism. The Darwinian process is suppose to create complex things by doing it in tiny steps. I don't think most persons would buy into a naturalistic creation process that produces complex biological things in one fell swoop.
Evidently even an atheist like Richard Dawkins feels the same way. Notice what he says:
"Evolution is very possibly not, in actual fact, always gradual. But it must be gradual when it is being used to explain the coming into existence of complicated, apparently designed objects...... For if it is not gradual in these cases, it ceases to have any explanatory power at all. Without gradualness in these cases, we are back to miracle, which is simply a synonym for the total absence of explanation."
Another quote from Dawkins:
"We have seen that living things are too improbable and too beautifully 'designed' to have come into existence by chance. How, then, did they come into existence? The answer, Darwin's answer, is by gradual, step- by-step transformations from simple beginnings, from primordial entities sufficiently simple to have come into existence by chance. Each successive change in the gradual evolutionary process was simple enough, relative to its predecessor, to have arisen by chance. But the whole sequence of cumulative steps constitutes anything but a chance process, when you consider the complexity of the final end-product relative to the original starting point. The cumulative process is directed by nonrandom survival. The purpose of this chapter is to demonstrate the power of this cumulative selection as a fundamentally nonrandom process."
Thus, we can see that Dawkins accepts the improbability argument and tackles it head-on rather than duck into a metaphysical escape hatch. In a later book, he makes the same point, but even more strongly:
"...To this day, and in quarters where they should know better, Darwinism is widely regarded as a theory of 'chance'. It is grindingly, creakingly, crashingly obvious that, if Darwinism were really a theory of chance, it couldn't work. You don't need to be a mathematician or physicist to calculate that an eye or a haemoglobin molecule would take from here to infinity to self-assemble by sheer higgledy-piggledy luck. Far from being a difficulty peculiar to Darwinism, the astronomic improbability of eyes and knees, enzymes and elbow joints and the other living wonders is precisely the problem that any theory of life must solve, and that Darwinism uniquely does solve. It solves it by breaking the improbability up into small, manageable parts, smearing out the luck needed, going round the back of Mount Improbable and crawling up the gentle slopes, inch by million-year inch. Only God would essay the mad task of leaping up the precipice in a single bound."
Dawkins agrees useful devices cannot be explained as coming into existence by chance and that if Darwinism were really a theory of chance, it couldn't work. He can afford to grasp the problem by the horns because he thinks he has a solution: It solves it by breaking the improbability up into small, manageable parts, smearing out the luck needed, going round the back of Mount Improbable and crawling up the gentle slopes, inch by million-year inch.
Now, notice what Mike Gene has to say about this:
"The problem is that Dawkins explanation (gradualistic, step-by-step, Darwianian evolution) breaks down when confronted by IC (see the section of my essay entitled, Irreducible Complexity Again). Don't lose sight of the big picture. Behe used the concept of IC as a challenge to the Darwinian mechanism, not "evolution." He explicitly cited IC in response to Darwin's challenge. And it should be clear by now that Behe succeeded (despite all the naysaying from all the Behe-critics). When it comes to the origin of IC, Darwin has been abandoned. We can see now, from the ID critics response, that in Darwin’s place, we get the raw metaphysics of the non-teleologist, invoking pure chance for the origin of machines. The answer? The flagellum was poofed into existence by chance. The argument ID critics use is a justification of invoking such poofing, which basically argues that with enough tries, something like the flagellum will poof into existence. This is thus a tacit concession that the Darwinian mechanism fails to explain the origin of IC.
The question then is why non-teleologists would want to arbitrarily and conveniently invoke chance only for the origin of IC. Why not let this logic spill over into all other areas of biological inquiry? ....
It's not surprising that Dennett's logic leads him to propose the Many Worlds Hypothesis to circumvent the Anthropic Principle, as the same basic argument holds there. But consider what this means. Let's say that human beings turned out to have a completely different genetic code and that none of their proteins showed any similarity to any other creature on this planet. Again and again, non-teleologists have demanded that we find something like this before inferring ID. But lookie what happens if we did. We could always invoke the Multiple Worlds Hypothesis and argue that in an infinite number of Universes, by chance, one with humans like this was bound to pop into existence. And ours just happened to be the one. Highly improbable? Yes, but not if we factor all those multiple universes into the equation. Thus, we could easily explain such humans as something that fell together by chance.
But it gets even more interesting. In the Multiple Worlds Hypothesis, by chance, a Universe was bound to pop into existence where it looked like things evolved, but they did not. And that Universe just happens to be ours. Thus, all of the ID critics evidence for evolution has now been explained away as one big coincidence. That our universe came into existence with all these amazing coincidences that look like evolution doesn't mean it had to come into existence like this. Thus, just as one can use Dennett's logic to attribute the data associated with the concept of IC to chance, we can likewise use the same basic logic to attribute the data associated with the concept of evolution to chance.
I have maintained that sooner or later, all disputes about these issues will boil down to a judgment call: "Thinkest thou that this world is governed by haphazard and chance? Or rather doest thou believe that it is ruled by reason?" - Boethius (470-525). 1500 years of knowledge have brought no real change."
[ 26. October 2002, 17:12: Message edited by: Jack ]
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Frances
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Member # 169
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posted 26. October 2002 17:16
Jack and others,
Thank you for your thoughtful responses. I realize that hypotheses testing, probabilities are quite tricky concepts to our 'common sense'. I wish I could admit that the concepts are fully clear to me but I have been reading a lot on hypotheses testing (both frequentialist (Fisher) and Bayesian). I believe that the essential part of the argument is the following:
Assume the following
p --> q (if hypothesis p is true then data q would be collected)
Now you did not collect data q then neither p happened
~q --> ~p
But does this imply that that the alternative hypothesis implies the data you collected (~p --> ~q)? This is known as the logical fallacy of affirming the consequent.
So we are testing the hypothesis X assuming the null hypothesis H[0] and thus look at P(X}H[0]) but what we do not know is the probability of our alternative hypothesis given the data we observer P(H[A]|X)
In fact even if it can be shown that P(X|H[0]) were small, the alternative P(H[0]|X) could still be large and consequently P(H[A]|X) would be quite small
Source
The following webpage identifies some of the common pitfalls with frequentialist approaches to hypothesis rejection/acceptance.
A more technical paper describes the similar pitfalls.
quote:
The traditional null-hypothesis significance-test method, more appropriately called "nullhypothesis
decision (NHD) procedure," of statistical analysis is here vigorously excoriated for its inappropriateness as a method of inference. While a number of serious objections to the method are raised, its most basic error lies in mistaking the aim of a scientific investigation to be a decision, rather than a cognitive evaluation of propositions. It is further argued that the proper application of statistics to scientific inference is irrevocably committed to extensive consideration of inverse probabilities, and to further this end, certain suggestions are offered, both for the development of statistical theory and for more illuminating application of statistical analysis to empirical data.
Jack: About Sober Is he saying that a purely chance hypothesis is better than an ID hypothesis when it comes to explaining the origin of complex things like molecular machines?
Nope. He is saying that we need ID hypotheses to determine which hypothesis is the more likely one.
About Mike Gene's argument Behe used the concept of IC as a challenge to the Darwinian mechanism, not "evolution."
If that is correct then IC perse cannot be used as evidence of ID after all but only against Darwinian mechanism. But things get worse since Behe actually admits that indirect Darwinian pathways may be possible but they have low probability, although no such computations have been provided. So at most one can state that IC is an argument against _DIRECT_ Darwinian pathways but that leaves a whole lot of pathways (Darwinian indirect, or non-Darwinian pathways) to be considered. In fact indirect pathways have been provided although at the moment we may lack the data to determine their probabilities.
The prosecutor's fallacy explains some of the common pitfalls of statistics.
Now the following question was raised by Jack
quote:
This does not give recognition to the fact that design explanations must be placed in a different category than chance explanations. As Philip Page has said, they are different modes of explanation. Given some assumptions we can calculate the probability of some phrase, for instance -- say "Now is the time for all good men to come to the aid of their country" -- under a chance hypothesis (27 ^ 68). How do we calculate the probability under a design hypothesis? Well once the phrase was in my head, and I started to type it, it became 1. But I might have leaped to "The quick brown fox . . . " instead. Or "methinks . . ." Design likelihoods, prior probabilities, and posterior probabilities, are necessarily ambiguous under design hypotheses. Yet Sober (I think) wants to have the apples compete directly with the oranges.
The relevant hypothesis is not what did you have in mind but is what you typed more likely to be random versus something you may have typed in the English language? The chance hypothesis can be evaluated by considering the likelyhood of the phrase falling in place given 26/52/xx characters in the alphabet and assuming a random distribution. Now how do we determine the likelihood of an english sentence? The english language is quite constrained in its occurrence of letters as well as words. Since letters form words and certain combinations are quite uncommon (XZQ) while others are quite common (ERS) one can forumulate a hypothesis about the English language. Words also are not random but occur in somewhat predictable order (grammar) and frequency (vocabulary). But then we have additional problems, what if one were to catch these regularities in the english language and let this algorithm produce a phrase? How does one determine if the phrase is algorithmic or intelligently designed? We may very well have a high probability of the phrase being algorithmic if we do not know the context of the statement been made, it all depends on the length of the phrase, contradictions inherent in the phrase that may use help detect who 'dunnit'. Perhaps by obtaining a large corpus of texts produced by the intelligent designer we can identify patterns which are indentifiers for the designer? Rejecting pure chance per se is not evidence of intelligent design per se, and certainly leaves open algorithmic design, cut-and-paste.
So the case for intelligent design versus pure chance may be strong, although a low probability does not make something unlikely to have happened. We all know that low probability events happen.
What does make the situation a bit more complicated is that we do know that intelligent designers use the english language which makes the a priori probability for intelligent design quite large but what if the author did not speak a word of English? Which hypothesis would be more likely then?
[ 26. October 2002, 17:59: Message edited by: Frances ]
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Mark Szlazak
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posted 26. October 2002 18:33
Jack,
FYI: Dennett's use of the Many-Worlds interpretation for Quantum Theory is a Red Herring. That idea is so far a non-theory for quantum phenomena. See my last post in the discussion threat "process and the aether."
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Jack
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Member # 265
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posted 26. October 2002 19:26
Frances>>About Mike Gene's argument, Behe used the concept of IC as a challenge to the Darwinian mechanism, not "evolution."
If that is correct then IC perse cannot be used as evidence of ID after all but only against Darwinian mechanism. But things get worse since Behe actually admits that indirect Darwinian pathways may be possible but they have low probability, although no such computations have been provided. So at most one can state that IC is an argument against-DIRECT- Darwinian pathways but that leaves a whole lot of pathways (Darwinian indirect, or non-Darwinian pathways) to be considered. In fact indirect pathways have been provided although at the moment we may lack the data to determine their probabilities.<<
I'm not so sure that indirect evolution can be properly called Darwinian. In any event, the evidence most often cited for Darwinian evolution involves direct evolution {i.e. peppered moths, finch beaks, antibiotic resistance etc.} You claim that leaves a whole lot of indirect pathways but these indirect pathways rely on pure chance. So we are back to my main point, namely, evolution isn't convicing if it's mechanism for producing IC systems is pure chance. And evolution without natural selection isn't Darwinian.
That's why Dawkins says:
"Evolution is very possibly not, in actual fact, always gradual. But it must be gradual when it is being used to explain the coming into existence of complicated, apparently designed objects...... For if it is not gradual in these cases, it ceases to have any explanatory power at all. Without gradualness in these cases, we are back to miracle, which is simply a synonym for the total absence of explanation."
Notice that Dawkins doesn't use a probability calculation to determine what the odds are of complicated, apparently designed biological things coming into existence via pure chance but he none-the-less rejects a chance hypothesis. Like the ID theorist, Dawkins assumes the probabilities to be so high that the chance hypothesis to him has no explanatory power at all. Is ID competing against a hypothesis that has no explanatory power at all?
[ 26. October 2002, 19:38: Message edited by: Jack ]
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Frances
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Member # 169
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posted 26. October 2002 19:42
Dear Jack.
Even if you are correct that Darwinian pathways cannot be indirect, this does not argue in favor of ID at all. I am glad that you have used the primary literature "Behe, Darwin's black box" page 40. I think that Behe's problem and the problem with your argument is that he considers such indirect pathways to be 'chance' only
I do not understand your Dawkins quote, Where does he claim that ID is competing against a theory with no explanatory power at all? Dawkins argues, perhaps correctly perhaps not, that what is required is 'gradualism'. Nor are indirect pathways pure chance either.
A classification of possible routes of Darwinian evolution describes some suggested indirect pathways.
So let me repeat my confusion about your claims again: What makes you suggest that ID is competing agaist a theory that has no explanatory power? And how do you suggest in the first place an ID theory might be competing? Do you have any particular theories in mind?
[ 26. October 2002, 20:43: Message edited by: Frances ]
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Jack
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posted 27. October 2002 01:44
Frances>>So let me repeat my confusion about your claims again: What makes you suggest that ID is competing agaist a theory that has no explanatory power? And how do you suggest in the first place an ID theory might be competing? Do you have any particular theories in mind?<<
I don't believe I called ID a theory. If I implied that, I didn't mean to. ID is an inference. Right now, my design inference is constrained to the origin of life.
You said in your first post to this thread:
"So it seems quite clear that in the absence of any independent evidence supporting ID, Darwinism has the upper hand in that it proposes hypotheses."
I don't know what you would consider as independent evidence supporting ID. Perhaps you have presented this but I don't recall it off hand. I do know that most ID critics won't accept anything less than an interview with the designer, or some extraordinary evidence such as a secret message encoded in the cell that says "made by God", or proof that something couldn't have come into existence by chance.
Mike Gene has proposed testable ID hypotheses but they are rejected by ID critics because they don't include any of the above. And ID hypotheses never will. Nor should they have to.
Now, what exactly is the Darwinian hypothesis for the orign of the eubacterial flagellum?
The paper you provided a link to, "A Classifcation of Possible Routes of Darwinian Evolution" by RICHARD H. THORNHILL AND DAVID W. USSERY, I read two years ago. Mike Gene examined it and concluded that the indirect evolutionary routes all invoke pure chance. I can email you Mike's response if you would like to read it.
As I see it, all you are proposing is that an inference that the flagellum originated via chance is better than an inference that it originated via intelligent design. I maintain that that is a weak argument. Dawkins evidently thinks so because he says:
"...To this day, and in quarters where they should know better, Darwinism is widely regarded as a theory of 'chance'. It is grindingly, creakingly, crashingly obvious that, if Darwinism were really a theory of chance, it couldn't work. You don't need to be a mathematician or physicist to calculate that an eye or a haemoglobin molecule would take from here to infinity to self-assemble by sheer higgledy-piggledy luck. Far from being a difficulty peculiar to Darwinism, the astronomic improbability of eyes and knees, enzymes and elbow joints and the other living wonders is precisely the problem that any theory of life must solve, and that Darwinism uniquely does solve. It solves it by breaking the improbability up into small, manageable parts, smearing out the luck needed, going round the back of Mount Improbable and crawling up the gentle slopes, inch by million-year inch. Only God would essay the mad task of leaping up the precipice in a single bound."
The problem is that Dawkin's explanation {gradualistic, step-by-step, Darwinian evolution} breaks down when confronted by IC systems like the flagellum. The non-teleologist is left with nothing more explanatory than origination through chance. And as Dawkins says:
"if Darwinism were really a theory of chance, it couldn't work."
[ 27. October 2002, 01:15: Message edited by: Jack ]
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warren_bergerson
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posted 27. October 2002 07:39
Mark,
Quote: Explanation in the classical sense is unattainable and Falsificationism in it's true sense can't deal with these situations.
This position might be widely held but it is simply not true. Classical deterministic explanations of complex phenomena like evolution are possible and represent a third alternative to the chance and design by a designer hypotheses.
The common belief that process such as evolution must be indeterminate or chance arises from a misunderstanding of both the concept of determinism and the role of determinism in expressing scientific theories. The classic misinterpretation suggests that the universe is controlled by a handful of simple deterministic laws and that scientists in formulating theories are identifying these deterministic laws.
This misinterpretation of determinism ignore two features. First, no matter how much data is collected, the data does not support a single law or deterministic relationship but an infinitely large set of different possible laws or causal relationships. Second, scientific theories do not represent what occurs and is observed in the real world. Scientific theories represent what happens in an idealized world or in the real world under ideal conditions.
If one recognizes these two features of deterministic relationships, and one recognizes that deterministic relationships can be expressed in many different forms, including dynamic causal relationships and teleological causal relationships, then one recognizes that complex relationships such as evolution can be expressed by deterministic scientific theories.
The argument that evolution comes down to a choice between chance and design by a designer may be comforting to both supporters of neo-Darwinism and design by a designer, by it is not science. Science, real science, deals only with falsifiable theories representing or modeling deterministic causal relationships.
Arguably one of the central problems in applying the scientific paradigm to the analysis of life forms has been the technical problem of formulating falsifiable, testable, deterministic models and theories of the complex causal relationships associated with life forms. Once you solve this technical problem, the ‘scientific’ analysis of life forms fits quite nicely into classical scientific paradigm.
Not only is there a third ‘deterministic hypotheses’ alternatives to change and design by a designer, but the deterministic hypotheses are the only forms that qualify as scientific.
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Frances
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posted 27. October 2002 15:53
before addressing some of the statements made by Warren and Jack, let me also try to return to the original purpose of this thread namely the suggestion by Sober that we need ID hypotheses in order to determine the validity of the claims. I have dealt with Dembski's original claims and shown that they do not seem to match what Sober has in mind. Sober's criticism however shows that for instance Behe's IC argument which is both formulated in a strict sense "Darwinian mechanisms cannot generate IC systems" But later on Behe relaxes the argument to "indirect pathways may be possible but are unlikely". Thus the argument is reduced from a strict argument If IC then (not Darwinian) to If IC then (probability of Darwinian pathways is low). While the original argument is deterministic, the actual argument is probabilistic.
Additionally Mike Gene has suggested that Behe used IC as an argument against natural selection/Darwinism but Behe goes beyond this and suggests that IC systems are evidence of ID.
quote:
"In fact, my argument for intelligent design is open to direct experimental rebuttal. Here is a thought experiment that makes the point clear. In Darwin's Black Box (Behe 1996) I claimed that the bacterial flagellum was irreducibly complex and so required deliberate intelligent design."
...
"To falsify such a claim, a scientist could go into the laboratory, place a bacterial species lacking a flagellum under some selective pressure (for mobility, say), grow it for ten thousand generations, and see if a flagellum--or any equally complex system--was produced. If that happened, my claims would be neatly disproven.(1) "
Behe's argument however is not an argument for ID as much as an argument against Darwinian pathways. One should not confuse low probability of such pathways with evidence FOR ID. As Sober has shown 'modus tollens' arguments have no probabilistic analog.
Jack:
When I was using the term 'theory of ID' I was merely using it in the context of those who proposed the design inference (Dembski).
But if ID is competing against theories that have no explanatory power then how can it be competing if it were not a theory itself.
You say that ID is an inference. You are correct, at the moment IF the design inference has any chance of working THEN ID will still remain an inference based on negative evidence. But I looked up the meaning of inference and there seems to be some problems with applying the definition to ID
Inference:
1. The act or process of deriving logical conclusions from premises known or assumed to be true.
3. The act of reasoning from factual knowledge or evidence.
3. The act or process of inferring by deduction or induction.
4. The logical process by which new facts are derived from known facts by the application of inference rules. (Logic)
But if ID is competing against theories then how do you intend for it to compete?
Jack then asks Now, what exactly is the Darwinian hypothesis for the orign of the eubacterial flagellum?
Interesting question but a better question would be Now, what exactly is _a_ Darwinian hypothesis for the orign of the eubacterial flagellum? or is there a Darwinian hypothesis for the origin of the eubacterial flagellum
Realize that ID is up against not just 1 hypothesis but against a myriad of known and unknown hypotheses. And IF ID claims that it does not have any false positives then it does have to deal with unknown hypotheses as well. Dawkins may not like pure chance alone as an explanation but in order for ID to be infered ID has also to deal with such hypotheses.
You claim that Mike Gene has argued that the indirect routes all include 'pure' chance. Let me seek some clarification since Darwinian mechanisms include 'pure chance' as well.
Mike's article suggests that IC has found itself into peer reviewed literature. I assume that this was tongue in cheek since one may very well argue that astrology, creationism, voodoo have 'made it into the scientific literature'.
At most the article may be seen as a confirmation that science at this moment has no explanation for the flagellum but that is hardly surprising. Mike Gene seems not too impressed by the examples provided because they lack in detail. Fine, I will grant him that but that hardly means that thus IC systems cannot arise through natural means.
Lets jump to Mike's conclusion
quote:
The remaining explanations for IC are indeed possible, but without evidence to support them, there is no reason to seriously embrace them
I guess that means that Mike has also dropped the idea that ICness is supporting ID? After all there is no real evidence to support them either? One may object to 'just so stories' in science but one has to realize that the alternative 'just so stories' based on our ignorance are even far less impressive.
Thus let me reiterate that: What Mike considers to be Pure Chance is not much different from Darwinian mechanisms but ofcourse like Darwinian mechanisms it is more than pure chance. Let's look at the following proposed pathway for IC
What parts are pure chance and what parts are selection?
Step by step:
1. An autocatalytic system: Pure chance but selected for
2. Gene duplication: Pure chance (mutation) with potential for increased beneficial effects.
3. Mutation (pure chance): Neutral
Jack: The problem is that Dawkin's explanation {gradualistic, step-by-step, Darwinian evolution} breaks down when confronted by IC systems like the flagellum.
What breaks down at most is Darwinian aspects but gradualism and step by step need not break down. Thus unless chance in your argument includes regulariy (ala dembski) I would argue that your claim breaks down.
My argument is:
1. Ignorance: Do we know exactly what happened?
2. Comparisson of hypotheses: In order to evaluate which explanation is better we need actual hypotheses since the arguments are probibilistic, we cannot conclude support for alternative hypotheses when we can reject a hypothesis but need to determine actual probabilities. The argument namely is NOT that IC systems cannot arise naturally but merely that they are _unlikely_ to arise. How unlikely? More or less unlikely than through ID? How can we establish such? As Sober has shown we need to compare the actual hypotheses.
What complicates the whole matter as well is what can be considered IC and what not. Dembski's redefinition of IC has not done much to improve the situation as now arbitrarily indirect pathways seem to be arbitrarily eliminated by definition which requires the original function to be maintained. So now the IC hypothesis focuses on 'original function' in an attempt to reject indirect pathways. But then we need to determine if Darwin's original ideas requires original function or not. Dembski may argue at most that But the fact is that it is the scientific community as a whole that is ignorant of how irreducibly complex biological systems, for instance, emerge (molecular biologists James Shapiro and Franklin Harold, though not design theorists, readily concede this point). but does not deal effectively with hypotheses of how IC _may_ have arisen. In fact that evolutionary biology may not be able to deal with IC now, does not preclude it from doing so in the future. So once again, how is our ignorance of matter helpful in establishing design? Is design superfluous for life? We don't know since so far there seem to be an absence of hypotheses that deal with this. Furthermore so far I have not found any quotes from either scientist wrt irreducible complex systems. Shapiro argues that we remain so far ignorant about most Darwinian pathways quote:
There are no detailed Darwinian accounts for the evolution of any fundamental biochemical or cellular system, only a variety of wishful speculations."
Harold's quote
quote:
Cell biologist Franklin Harold in his most recent book, The Way of the Cell, remarks that in trying to account for biological complexity biologist thus far have proposed merely "a variety of wishful speculations." If biologists really understood the emergence of biological complexity in material terms, intelligent design couldn't even get off the ground. The fact that they don't accounts for intelligent design's quick rise in public consciousness. Give us a detailed testable mechanistic accounts of the origin of life, the origin of the genetic code, the origin of ubiquitous biomacromolecules and assemblages like the ribosome, and the origin of molecular machines like the bacterial flagellum, and intelligent design will die a quick and painless death
Does not present much support for the ID scenario either but merely points out our ignorance. But should our ignorance perse be evidence of support of ID? I would argue that given the claims of no false positives we cannot jump to such conclusions lest we risk the occurence false positives, leading to a contradiction.
Ian Musgrave has taken the first step in proposing a possible evolutionary pathway for the flagellum. Let this be the start of our scientific inquiry into the origin of this interesting structure.
Note that I am not saying that Ian is correct but if we are to accept Dembski, we need to now translate Ian's concepts into probabilities in order to reject it. Can we really expect probability estimates for such scenarios? Or is ID doomed to have to wait for what I believe to be the impossible? As long as scientists are learning more and more about the flagellum it seems premature to infer design. IC nor CSI seem to be reliable markers of intelligent design. At most we can claim that ID can generat IC or CSI but that's where it ends.
Now we may want to include the possibility of ID into science but how? At the moment ID is infered through elimination and that is what science is all about. Science however does understand 1) our limitations (read ignorance) 2) our inability to formulate probability estimates for most of these scenarios. The latter one of course is no problem for science but a significant roadblock to infer ID.
Hence my suggestion that ID proposes its own hypotheses. Without such ID is just NOT an explanation.
So what about the flagellum?
A new pathway for the secretion of virulence factors by bacteria: The flagellar export apparatus functions as a protein-secretion system
quote:
The homology between subunits that form the protein transport apparatus of the flagellum and the contact-dependent type III secretion apparatus combined with evidence that substrates of these apparatus are transported without modification suggest that the two systems are functionally related. This similarity has led to the hypothesis that these two types of apparatus share a common evolutionary origin
Certainly co-option seems to be a potential explanation for the observations?
Type III Protein Secretion Systems in Bacterial Pathogens of Animals and Plants
Proposes horizontal gene transfer as a way of spreading.
quote:
Type III secretion systems appear to have been acquired as intact genetic blocks by horizontal gene transfer during evolution. However, although the genes encoding the secretion apparatuses are clustered, the genes encoding the secreted proteins and some transcriptional regulators are often located in unlinked positions, indicating that these secreted targets and regulators have evolved independently of the core secretion apparatus and that these different components of type III secretion systems have adapted to form functional units
More relevant links pro/con evolutionary origins
Evolving the Bacterial Flagellum Through Mutation and Cooption By Mike Gene
See also
By Martino Rizzotti
Rizzotti argues that the flagellum may be derived from the ATPase system.
http://www.area.fi.cnr.it/eventi/bioevol/rizzotti.htm
Rizzotti M.: Origine del flagello batterico. VI incontro di biologia
evoluzionistica, Roma, 18-19 febbraio 1998a
Rizzotti M.: Prime tappe dell'evoluzione cellulare.
Decibel/Zanichelli, Bologna, 1998b
Rizzotti M.: The possible origin of the bacterial flagellum. Endocytobiology VII, Freiburg, 5-9 aprile 1998c Rizzotti M.: The possible origin of the bacterial flagellum. Endocytobiol. Cell Res. 1998d (in corso di stampa)
Another abstract in English
Rizzotti
The base of the bacterial flagellum is a rotating "molecular machine" which obtains its energy from an inflow of hydrogen ions. A similar machine, more fundamental and widespread, is bacterial ATP synthase.
Thus, the former may have derived from the latter. For this derivation, intermediate evolutionary steps may be hypothesised, as may also intermediate functions. It is not surprising that no intermediate structure is known in present-day prokaryotes, as intermediate structures usually become extinct during evolution. Confirmation of this possible origin of the bacterial flagellum may come from sequence and/or conformational homologies. These are more likely to be provided by the essential components of both structures, i.e., stator and rotor.
I contacted Rizotti but found out that he had recently passed away. The conference proceedings can be acquired for $150 dollars or so, a bit steep for my budget.
More players:
Macnab
Rosenbaum
Evolution of flagella From Wikipedia, the free encyclopedia.
quote:
In addition, the ATPase involved in flagellar construction is thought to be homologous to this family. Rizzotti, in his (2000) book Early Evolution has cited this in his scenario for the origin of the bacterial flagellum from an F1F0 ATPase. In light of the other homologies mentioned here, this is very unlikely, although there may be a connection between the F1F0 ATPase and transport systems at some very remote level.
The evolutionary origin and phylogeny of microtubules, mitotic spindles and eukaryote flagella. Cavalier-Smith T.
A classification of possible routes of Darwinian evolution. Richard H. Thornhill1 and David W. Ussery2
Finally a word of caution:
Don't get me wrong, I hardly consider the flagellum and its origins to be well established all I am trying to show is how science attempts to advance our knowledge through hypotheses which can be verified/falsified. However the rejection of a hypothesis can hardly be held as supportive of alternative hypotheses.
So far my statement would be about the flagellum origins: We don't know although various hyptheses have been proposed which are leading to a wealth of research.
Warren argues that Science, real science, deals only with falsifiable theories representing or modeling deterministic causal relationships.
What does Warren mean by deterministic causal relationships? Am I correct to infer from Warren's argument that 'real science' cannot deal in chance relationships. And why is Warren using chance to describe evolutionary mechanisms? Evolutionary science has been quite succesful in applying its theories and hypotheses. What more does Warren wants? What other deterministic processes does Warren have in mind? I find Warren's argument hard to follow since it is so vague and non-deterministic :-)
I am as always looking forward to Warren or anyone proposing alternative hypotheses/theories. But until then, should we just reject other hypotheses? Not really...
Perhaps Warren can help us understand, in a different thread preferably his ideas in a manner accessible for us all?
Also I would like to point to the excellent discussion between Deanne Taylor and Dembski about scale invariant networks and their relevance to IC systems, found on Brainstorms. I hope the discussion will continue to explore the contributions of this concept to IC systems.
And then a recent paper I ran across System level genetic codes: an explanation for biological complexity
[ 27. October 2002, 23:25: Message edited by: Frances ]
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Mark Szlazak
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posted 27. October 2002 19:17
Hi Warren,
When I say deterministic I mean what most mean in past and current science, basically mechanistic ideas or as I stated basically a Laplacian-type determinism.
Classical logic is supposedly very closely tied to this, so close that it has short comings in dealing with an "ontological" indeterminism that doesn't fall into the determimism just mentioned. The modern example is quantum mechanics.
A determinism with final causation isn't what I'm thinking about.
In any case, the possibility that we live in a indeterministic reality, a reality in which deductive-type explanations are only approximations of patterns of aggregate data but impossible for the single case, is very real.
This limits many if not all forms of deductivism.
However, even if one believes that we live in a strictly deterministic universe, strict deductivism (nothing but deduction and no induction) is also untenable in the empirical sciences. For instance falsificationism doesn't work for existential statements like "There is (or there exists) a white raven", but verificationism does. I'll briefly give some other points pulled out of the book "The Limitations of Deductivism", ed. Adolf Grunbaum and Wesley C. Salmon. First, Hempel's argument concerning privisos and theoretical ascent. Second, Kyburg's point about measurement and the treatment of errors. Third, Salmon's argument that pure Popperian deductivism cannot provide the kind of guide to the future that is needed for rational behaviour. Check it out!
[ 28. October 2002, 00:31: Message edited by: Mark Szlazak ]
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warren_bergerson
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posted 28. October 2002 11:30
Frances and Mark,
The analysis being discussed is based on the premise or assumption that there are only two types of hypotheses to be considered. Those two types of hypothesis can be labeled 1) chance versus design by a designer, or 2)Darwin versus design by a designer. As should be obvious, the whole analysis is totally useless and meaningless if there are more than two options. If there exist other options such as non-Darwinian, non-chance, deterministic, materialistic hypotheses then the analysis is a meaningless waste of time.
The ‘Darwin versus designer’ or ‘chance versus designer’ analysis is not only based on a dubious and insupportable assumption, but it is based, I would argue, on an assumption that contradicts a fundamental principle of scientific analysis. Scientific hypothesis, or real scientific hypothesis, I suggest, are always ‘one failure falsifies’, predictive, deterministic models of observed real world occurrences.
Since any set of observed occurrences will always be finite, there will always be a deterministic relationship which fits or explains the observed data. There will in fact always be an infinite number of deterministic models or explanations of any set of data. In principle, the choice in scientific analysis is between different deterministic models, explanations, or hypotheses. Since there are always an infinite number of such hypotheses available, there is never a need to consider indeterminate hypothesis or explanations based on external designer. From a philosophy of science/mathematical perspective, ‘real’ science considers only deterministic explanations meeting certain requirements because there always an infinite number of such materialistic/deterministic explanations.
While it is widely recognized that there are always an infinite number of possible deterministic models/hypotheses for any set of observations, it has proved very difficult to find practical methods of expressing the types of complex causal relationships associated with life forms. The failure/inability to solve this practical/technical issue has led attempts to rationalize the acceptance of scientific hypotheses which do not satisfy rigorous deterministic standards.
The absurdity/inappropriateness of discussing scientific analysis of design by an non-material designer would not even arise if portions of the academic/scientific community had not abandoned rigorous standards for formulating evolutionary theories. It is appropriate to consider materialistic/deterministic design process hypotheses as alternative to Darwinian theories. It is not, however, appropriate to consider design by external designer hypotheses as part of scientific analysis.
It is also important to note that the question being addressed is not whether the physical universe is deterministic or non-deterministic. Such a question is essentially meaningless. The question is whether scientific analysis and formulation of scientific hypotheses should be based on the assumption that causal relationships can be described and analyzed as deterministic.
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