The DI loves to put out lists of scientists who "dissent from Darwinism". Because such lists make no actual arguments, they are pure appeals to authority. That authority is often misplaced, of course, since a large percentage of those on the list have no more training in the relevant fields (fields where evolutionary theory is involved) than a non-scientist would have. According to the NSF, there are 543,580 scientists in the US (that doesn't include engineers). Which means that even if we grant them all of the engineers and all of the scientists with no training at all in evolutionary biology and presume that all of them are in the US (which is false), their list still represents less than 1/10th of 1% of all scientists in the US. Take out all the engineers and irrelevant scientific credentials, and it falls to less than 5/100ths of a percent. Which is still smaller than just the scientists named Steve who have declared the validity of evolutionary theory. But even that is just the beginning. In Australia, an organization of 70,000 scientists has declared ID unscientific. The same is true of the American Academy for the Advancement of Science, which represents 120,000 American scientists. That's why I'm always amused to see the DI trumpeting such appeals to authority - if they really want to play that game, they're going to lose, and I mean lose big. That doesn't matter to them, of course. They know that their followers don't really care about logical consistency. All their followers care is that there are actual scientists, or at least really smart people who say they're right. And never mind the hundreds of thousands who say the opposite.
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well, if Like in Kansas, they can keep redifining science, they can make the list bigger...
Even one who dissents could be substantial...depends on the reasoning. Just pointing out that the numbers are pretty insignificant...unless science is determined by a plurality.
For those on the ID side who are "lay-people", it could be satisfying to know that some don't view the "science" of Evolution as the Origin of Humans to be the CERTAIN truth.
the numbers are only significant...
...if they are growing (to show that not all are SOLD)
...to show that ANY don't agree with the established "fact"
I guess for guys like you, it is significant in that these numbers are used in a "grassroots" sort of way to garner support or, worse, validity - be it false or not.
Hmmm...i do understand your ire.
Ed's post doesn't address the issue of just exactly what the listees disagree with--the usual pablum is something to the effect that some scientists don't entirely agree that the mechanism discussed by Darwin fully accounts for all of evolution--the sort of thing that anyone could agree with, considering the considerable progress of the past 150 years. How many of the listees would say that they agree that Intelligent Design Creationism provides more, and better, explanations for biodiversity than does evolution science? For that matter, how many of the listees could explain just what it is that ID explains, and how it does so?
There is very little point in pushing numbers on the ID's at DI. You don't expect those who can't understand chance mutation and cumulative selection to understand probability theory, do you?
I'm on the list. It is a list of people who agree with something--not disagree. We agree with the statement:
"We are skeptical of claims for the ability of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged."
That's all there is to it.
Udontno wrote:
And I agree with you completely. My problem with such lists is that they are pure appeals to authority. They make no actual arguments, so there is nothing that can be analyzed or evaluated. They exist solely as a large logical fallacy. But if one is going to use appeals to authority, they can hardly then whine about appeals to legitimate authority or appeals to consensus within that legitimate authority.
David Heddle wrote:
The distinction here between agree and disagree is entirely arbitrary, of course - the statement begins with skepticism, that is disagreement, about another idea. But that's neither here nor there. There are two problems I have with your name being on that list, David.
First, you are a nuclear physicist with, presumably, no more training in biology than I have. I would never put myself foreword as having any authority or expertise in evolutionary theory. But since such lists make no actual arguments, they exist solely as appeals to authority, and in this field you simply have no authority. You're a very bright guy, no doubt. But they don't make lists of "very bright guys who dissent from Darwinism". They specifically list "scientists" for full PR effect, because scientists are viewed as having some actual expertise in this area. But a nuclear physicist has no more expertise in biology than a biologist has in nuclear physics. A biologist who put his name on a list as someone who dissented from relativity would not be taken seriously as a legitimate authority on that issue, and neither should you be in this case (which doesn't mean you can't know what you're talking about on this issue; it just means that the mere fact that you are a scientist tells us nothing at all about whether you do).
The second problem is with the statement itself. As I've written many times, the statement is virtually meaningless. I agree completely with the statement, yet I am a staunch advocate of evolutionary theory. The statement was written by someone who simply does not understand evolution. The fact that so many would sign on to it thinking that they are "dissenting from Darwinism" is evidence that they don't really understand it either. Even the most dogmatic of adaptationists, like Richard Dawkins, could agree to that statement. It means virtually nothing.
Well I can only speak for myself. I had to think about it for a while before I signed. I actually have no problem with evolution--as you say I have no expertise in the field. So as far as evolution is concerned, I felt comfortable signing it because it was so generic: of course careful examination of the evidence for Darwinian theory should be encouraged.
I am skeptical of present views--such as they are--of abiogenesis. Now I know that evolutionists will say that is an altogether different field--but I have never accepted that claim--I view it as an argument of convenience--sweeping a difficult problem under the rug. So in my mind the skepticism part of the statement is aimed at abiogenesis.
(I have, in fact, suggested to bio-IDers that they concentrate on abiogenesis rather than evolution, but I don't think any of them pay any attention to what I say.)
David Heddle wrote:
And that is exactly the problem with it - it's so vague that anyone could sign it, including full blown "Darwinists". This is very slippery, PR-driven language, designed (intelligently, I suppose) to obscure rather than enlighten. This is the sort of thing done as part of a PR campaign, not a genuine search for truth. When Wegener found his ideas about continental drift rejected by his fellow scientists, he didn't organize a political lobbying firm to get his ideas into classrooms. He didn't hire a big PR firm to sell his ideas. He didn't publish lists of "dissenting" geologists or push to teach "the controversy". He simply got to work establishing the validity of his theory, gathering and publishing data and honing his explanations. That's how science operates. And frankly, a scientist should not sign on to this kind of marketing campaigns, especially when they know that they're so vague and insubstantial that anyone could sign on to them and when they know that their name attached to it will be used solely as an appeal to (in this case illegitimate) authority. (/soapbox)
Ed,
I disagree with at least part of your statement. Anyone could sign the part about encouraging examination of the evidence--or at least nobody should object to it. But I doubt Dawkins would agree with the "skeptical" part. That implies something more. As I said, in my case I applied that part of the statement to abiogenesis.
Do you have a similarly negative view of the Steve list--or is a response-in-kind to what you see as a dishonorable strategy (if I understand correctly) acceptable?
I signed the list because I don't like cottage cheese.
Now I know that evolutionists will say that is an altogether different field--but I have never accepted that claim--I view it as an argument of convenience--sweeping a difficult problem under the rug. So in my mind the skepticism part of the statement is aimed at cottage cheese.
I feel my scripture science diploma counts me in.
David Heddle wrote:
I bet he would. I know I would. In fact, I'd go even further. I would say that I emphatically disbelieve that random mutation and natural selection can account for the complexity of life we see around us. At least some of that complexity is the result of non-mutational variation and non-selective mechanisms for fixing variation within a population. Dawkins might quibble over how much of it can be attributed to non-selective or non-adaptive mechanisms, but even he would not argue that selection drives every single preserved trait.
The point of the Steve list is only to point up the absurdity of such lists. It is not intended as any sort of appeal to authority, or to prove any point at all other than to make fun of the absurdity of presenting such appeals to authority. As such, I have a positive view of it.
Ed,
Perhaps, but to me that is splitting hairs. I would view the clear spirit of the statement as "we are skeptical of the current theories that purport to explain the complexity of life." Although I know the statement was meant to be broad, I did not and do not believe that an intentional loophole was left so that nobody could, in principle, object--I believe the DI wanted a list of dissenters, not a list of people who understood that the precise wording could not be refuted.
It's like the bumper sticker: "Abortion stops a beating heart." It is beyond refute, but we all know that anyone displaying the sticker is taking a pro-life stance.
To say that Dawkins would sign the statement because he would concede that technically it is true is like saying Patricia Ireland would put the aforementioned bumper sticker on her car because she recognized it as technically correct.
But I could easily be wrong.
David, do you see anything incongruous about these two statements?
Eric,
No. I am a scientist--and just because I am not an expert in evolution, I know what evolution is. And I know what abiogenesis is. And I view their separation as artificial.
This reminds me of an argument I got into with one of the guys at Stop the ACLU. He posted something about the supposed link between abortion and an increase in breast cancer risk, which sounded preposterous to me. He quoted a "leading expert" - who happens to be a born-again Christian - on the issue who said there was a definite link between abortion and breast cancer risk. I provided a link to a site covering a conference sponsored by the National Cancer Institute, the result of which was over 100 doctors and researchers denying the ABC link. Reading further, I found out that the "leading expert" the Stop the ACLU guy quoted was at that conference and that filed a minority dissenting opinion on behalf of everyone at the conference who didn't agree with the majority opinion. And by everyone I mean just the "leading expert" and no one else. Any guesses as to whether or not the Stop the ACLU guy changed his mind after I presented that to him?
It's amazing how some people are willing to ignore an overwhelming number of scientists and a mountain of evidence if they can find just one guy who believes what they want to be true.
David - it's noteworthy:
"I KNOW what evolution is. And I KNOW what abiogenesis is. And I VIEW their separation as artificial."
[emphasis mine] - at what point does your knowledge become incomplete?
Rich,
Do you what physics is? Do you know what Newton's laws are? Do you know how to renormalize a Lagrangian?
I assume the answers are yes/yes/no, which qualifies you to say certain things about physics, while not claiming to be an expert.
Well mr Heddle.
Why do you think the list is about "we are skeptical of the current theories that purport to explain the complexity of life."
It doesn't say that. In fact it specifically lists what the signer is sceptical about (not abiogenesis), random mutation, selection and darwinian theory.
Since you are so well versed in evolutionary theory you must surely agree that this in no way describes "current theories" in evolution?
There seem to be a disconnect in your reasoning.
I know for sure that the DI would love it if people experienced the list as "dissenters" from current evolutionary theory, but it is no such thing. Like you said, its just people agreeing with the fact that what Darwin put on paper 150 years ago is not the whole truth, and that we should all be sceptical of science. Not much dissent there.
/Soren
Heddle:I would view the clear spirit of the statement as "we are skeptical of the current theories that purport to explain the complexity of life." Although I know the statement was meant to be broad, I did not and do not believe that an intentional loophole was left so that nobody could, in principle, object--I believe the DI wanted a list of dissenters, not a list of people who understood that the precise wording could not be refuted.Here's what the DI wanted: a statement that the general public would look upon as "skeptical of current theories" as synonymous/interchangable with "mutation+Darwin's n.selection", not knowing the other mechanisms -- but would also rope in respected, mainstream bio-people like Stanley Salthe and Martin Poenie who emphasize other mechanisms besides RM&NS, adding prestige as signatories. (Both have since recognized the use the scam was for and retracted. Not the only ones.) I'm sure DI chief at the time, Stephen Meyer, philosopher accompished in parsing, knew exactly what he was doing.
It should be noted that appeals to authority aren't always fallacious. There are times when it is and isn't logically appropriate.
That's not to see there aren't problems with the DI list. There are many. There are times when it is perfecty appropriate to rely on the authority of others to help us understand what is reasonable to think. You don't actually need to perform all the experiments that undergird the theories in a chemistry textbook to reliably think most of the information found therein is sound knowledge.
David Heddle wrote:
I don't doubt that the DI wanted a list of actual dissenters. But the point is that the version of evolutionary theory (or "Darwinism", whatever the heck that is) that they present is a straw man. It means one of two things: either they don't understand what evolutionary theory actually says, or they are intentionally oversimplifying it. Either one speaks volumes, I think. The very fact that so many "experts" signed on to the statement without recognizing that it really doesn't mean anything also speaks volumes. Again, this is an exercise in marketing and PR, not an honest search for truth.
Your last statement contradicts the first two.
Evolutionary theory shows how abiogenesis might be possible, but tomorrow it were somehow proven that all life on this planet came from Mars (or was created by Q, or whatever), then the argument for the origin of life's current diversity would still stand.
Do you what physics is?
>>Not enough to put my name on a petition of experts in good faith.
Do you know what Newton's laws are?
>>Not enough to put my name on a petition of experts in good faith.
Do you know how to renormalize a Lagrangian?
>>More church should renormalize him, I suspect.
David Heddle:
Then perhaps you would like to describe how the question of Abiogenesis is amenable to explanation by the mechanisms (mutation, genetic drift, natural selection, etc) in an Evolutionary Biologist's toolkit. If it instead requires the tools of some other field(s) (e.g. Biochemistry, Organic Chemistry, Geochemistry, Astrobiology or whatever), I would consider that to be a strong indication that it legitimately lies in a separate field. That is generally how the demarcations work in science isn't it?
Abiogenesis very well might be amenable to explanation by mechanisms relevant in evolutionary change. The issue is that the origin of biodiversity is distinct from the origin of life. The only time the two issues would strictly overlap is if the origin of different organisms features were to be explained by independent origin of life events. Magical faires could poof the existence of life on earth from the ethereal plane of "lifeness" and evolutionary theory proper wouldn't be touched. It presumes that there is initial organism or pool of organisms from which the tree of life branches out. There is enough reason to suspect that it developed chemically from prebiotic chemistry, but it doesn't matter if it did or didn't. What does matters as far as evolution is concerned is that the diversity of features found among organisms can be explained by descent with modification from previous organisms down to common ancestors.
This conversation is taking multiple directions. I want to summarize.
The original point was whether or not the DI statement meant anything. Ed (correct me if I am wrong) said it was so vague that anyone could sign it. The "skeptical" part is meaningless, Ed said, because it does not enumerate all evolutionary mechanisms. My position is that said omissions were not made with malice aforethought, and the intent of the statement was that modern science cannot explain the complexity of life--with which I agree.
Then there was a tangential issue as to whether it is seemly for scientists to sign lists that will be used for PR purposes. My view is that the actual problem is with this particular list. In the late 80's, I left a job as a scientist doing "Star Wars" research and took a research faculty position at the University of Illinois. At that time, there was a nationwide petition signed by science faculty stating that "Star Wars" would not work and that their respective universities should not take related research monies. Most people signing the list were not experts, yet they signed a statement regarding, ostensibly, the science of Star Wars, not the politics. And the list was used solely for PR. Would you have been against that list?
There are the usual questions I get about my qualifications, being a physicist. Again, I don't think it is that I am a physicist that is the problem--but that I am a physicist who takes an unpopular stance. I don't hear many people complain about Jason Rosenhous, a mathematician, writing about evolution--and I have to conclude that is because he takes an orthodox view. If he were an IDer and a mathematician...
Then there is the question of the distinction between abiogenesis and evolution, which I view as artificial. Some took that to mean that I view them as synonyms, which I don't. It's like the distinction between high energy physics and nuclear physics. There is a great deal of overlap and no clear boundary. I have never been at a talk where someone who identified himself as a nuclear physicist answered a question with "that's irrelevant, it's a high-energy physics question."
Abiogenesis and evolution are disciplines superimposed on a backbone of increasing biochemical complexity. The absurdity that they are neatly distinct would be made manifest if we could all watch a movie of the process--there would, I am certain, be heated disagreements on the point at which actual life began--that is, even if we could watch it happening we wouldn't agree on where to place the boundary. It's useful but artificial.
David Heddle writes:
I agree that one would be hard pressed to find the neat dividing line between the origin of life and the development of life thereafter. And it's pretty clear the theories on the origin of life are much more speculative than how life has developed in the last 600 Ma for example. But that doesn't mean one can't study the former without directly referencing the latter. Most chemists for instance spend their entire careers happily studying how matter interacts while giving the question of the origin of matter scarcely a second thought. Ditto for geologists, most of whom study processes happening (and have happened) on the Earth while virtually ignoring the question of how Earth formed in the first place.
Obviously the Earth had to have formed somehow, obviously matter had to have formed somehow, and obviously life had to have arisen somehow (assuming none of the above are eternal). These are valid scientific questions in and of themselves, but a satisfactory answer to them is not required to understand what happened afterward and what is happening today. Defining evolution by refering to the devopment of reproducing forms is no more artificial in my view than defining sedimentology or thermodynamics as they are.
But if one were to insist on some sort of supertheory of life, which includes both its initial formation and subsequent development, then I'd be the first to admit the former part of that theory is considerably shakier than the latter.
Of course the omissions were made with malice aforethought. Otherwise MEyer would have said what you claim to be the spirit of the statement - that evolutionary theory cannot explain life's diversity. The whole point of wording the statement that way is to allow as many reasonable people to sign it as possible, so that they can then claim these people support ID. When pressed they'll claim that dissenting from Darwin isn't the same as ID, but given that ID is just logically unconnected criticisms of Darwinian evolution it doesn't really wash. Furthermore, when actual biologists say that they could sign the statement (as could I, though I wouldn't) they can point to that and say "Look - even the biologists can't deny the truth of our arguments!" It's a carefully constructed propaganda tool against evolutionary theory and to pretend otherwise is deeply disingenuous.
Similarly to claim that the distinction between abiogenesis and evolution is artificial is absurd. Osmo puts it better than I could but the central point is clear. It doesn't matter what the mechanism of abiogenesis is - whether it's closer to creationism or evolution - given abiogenesis, evolutionary theory stands as a well supported, powerful explanation of life's diversity.
Were there not a few scientists who signed that list who either did not understand that it was a pro-ID, ant-evolution propaganda tool and/or where unaware that they had signed? I'm rather sure that at least one "signer" asked that his name be removed. (This issue was probably posted at Panda's Thumb.)
David Heddle wrote:
But it does indicate, quite clearly in my view, ignorance aforethought. Whether it also indicates malice is a judgement call that I'm obviously more likely to answer affirmatively and you're likely to answer negatively.
I do think there is a distinction between making statements of truth (as in the DI statement) and making statements of practicality (there was a very good argument to be made in the 80s that a Star Wars system, no matter how perfectly it worked, was impractical because the obvious response would be to overwhelm it, triggering a new arms race with the Soviet Union). Thus, the statement was no so much about the science as it was about the politics, the human reaction to the results of the science. I don't think they're strictly analogous. At the very least, one should not sign on to statements that are clearly inaccurate (if not intentionally misleading), as the DI's statement is. More importantly, I think I would have to see the actual statement you're referring to. If it made actual arguments for their conclusion, then I would say it's an entirely different matter. The DI's statement makes no arguments whatsoever, it is merely conclusionary - and that means that it can only be an appeal to authority. The fact that the statement is inaccurate and most of those who signed it have no authority is what shows the statement to be a sham.
No, you're missing the point. If Jason (or I, for that matter) signed a statement that is purely an appeal to authority, I would criticize him just as much for it as I do you. The question is not whether a physicist or a mathematicisn (or an educated amateur like myself) can understand evolution and make credible arguments concerning it; the question is whether someone without credentials, training and experience in an evolutionary field should present themselves as an authority on the subject. If the DI statement presented arguments, then those arguments could be evaluated apart from the question of authority, and that is obviously the preferred means of analysis. But since the statement presents no arguments or statements of fact to be evaluated, it can only be evaluated as an appeal to authority. And as such, the fact that it A) presents an inaccurate caricature of what evolution says and B) presents entirely unqualified people as authorities can only lead one to conclude that it is an exercise in deception.
No one is saying that since you're a physicist you have no knowledge of evolution and you can't speak out about it; what we are saying is that you have no more business to present yourself as an authority on the subject than I do, or Jason does. That's why you will never see my name on such a list, which is presented as an appeal to authority. I am perfectly content to have my arguments on this subject evaluated and debated, but I have no justification whatsoever to claim to be an authority.
Mark wrote:
There have been two people that I know of who have demanded their name be taken off the list.
I guess 'don't sign things you don't understand' remains good advice - especially if you define things differently than the rest of the world. Credit cards / mortgages, etc!
Lists of scientists are made because matters of science have political and social impact. These types of lists are also a matter of free speech.
I happen to be a creationist and I also am a physician and have a Phd in engineering. Only recently have I become interested in the mathematical probabilities of evolution. So far, the debate that I have seen on this issue on the web has disappointing. The arguements tend to be vague and often degenerate to statements that you don't have the expertise to comment or are not a scientist.
I wonder how the readers of this site would debate the example of probability of obtaining a particular protein by random additions of amino acids. In this model, one assumes that all amino acids are available in equal quantities, that each amino acid is just as likely as the next to bind to the protein and that there are infinite amounts of each amino acid so that as a given amino acid binds to the protein that the probability for another of that given amino acid is not affected.
Alan Kleinman wrote:
In other words, they're made as exercises in public relations and marketing. They are appeals to authority and nothing more; they have an "impact" because people automatically tend to assume that if a "scientist" - defined as broadly as one possibly can - agrees with their views, their views must be correct.
Nonsense. No one has ever challenged their right to make such lists. People have the right to say all sorts of stupid things; pointing out that what is being said is stupid is not a "free speech issue".
As soon as a creationist offers up a valid probability equation for the formation of such a protein, it might be debatable. But I have yet to see one. If you have one, please feel free to post it. I'll even spot you the first part of the equation - "P=".
Thank you Ed Brayton for spotting me "P=". Consider the following probability model for obtaining a particular protein by the random independent additions amino acids.
â¢The probability space is 20 L amino and 20 R amino acids
â¢The probability of any particular event in the space is 1/40 that is you have a 1 in 40 chance of getting any particular amino acid
â¢n is the number of amino acids in the protein
â¢Then, the probability for obtaining a particular protein n amino long is P = (1/40)n
The site didn't take my formating, the probability equation should be:
P = (1/40)^n
Such calculations are absolutely meaningless. You have no idea what the starting conditions are. You cannot calculate such a probability without knowing, at a minimum:
A) how many amino acids exist in solution, and at what concentration
B) how much time is involved
C) how many sequential and simultaneous trials are going on and under what precise conditions
D) whether and how some amino acids may bind more readily with others
E) whether any shorter proteins may be functional
F) how many variations of the protein may also be functional
And much more. And all of that assumes the process by which proteins are assembled is entirely random, which does not appear to be justified. Proteins are not formed simply by banging together as many atoms as one has over and over again until a particular protein is produced. Longer proteins evolve from shorter proteins. Unless a probability calculation can somehow include preservation of functional intermediates via natural selection, for example, it cannot possible replicate how proteins are formed in the real world. Thus, such calculations are literally meaningless. Such unreal calculations can be formed to show that practically anything that exists is too improbable. Marshall Berman gives a great example of such reasoning, which I will copy here:
Indeed. If one assumes absolute randomness, virtually anything becomes so improbable as to be folly.
Brayton wrote
Such calculations are absolutely meaningless. You have no idea what the starting conditions are. You cannot calculate such a probability without knowing, at a minimum:
Kleinman wrote
If you start from the premise that all mathematical modeling is an approximation (and simplified interpretation) of reality then the meaningful or meaningless of such calculations (modeling) is dependent on the assumptions one makes. I will try to make every assumption to the benefit of the evolutionist view. From an engineering point of view, calculations are often used to bracket an answer rather that get an exact result. This particular calculation is used to bracket rather than get an exact estimate. The question that needs to be answered is whether this calculation represents a lower or upper estimate of the probabilities.
Brayton wrote
A) how many amino acids exist in solution, and at what concentration
Kleinman wrote
Allow for infinite amounts of each amino acid, at least enough such that as amino acids are being used to build the protein, the probability for adding any amino acid stays at 1/40. Choose whatever concentration you want.
Brayton wrote
B) how much time is involved
Kleinman wrote
Allow for infinite time, however I think it can be shown that this assumption will ultimately hurt the evolutionist argument. Proteins are inherently unstable molecules subject to all kinds of chemical reactions. Since all living things use only L-amino acid, it is well known that proteins undergo nonenzymatic racemization which would denature any protein in very short periods of time. Proteins also would be subject to many different oxidation/reduction chemical reactions that would prevent them from staying in a given form for long periods of time. For the initial analysis, take as much time as you want.
Brayton wrote
C) how many sequential and simultaneous trials are going on and under what precise conditions
Kleinman wrote
As many sequential and simultaneous trials as you want. Choose the best conditions that would lead to amino acid binding. You need to recall that P=(1/40)^n is simply the algebraic representation of how many different combinations can be obtained when randomly choosing from 40 possible events n times.
Brayton wrote
D) whether and how some amino acids may bind more readily with others
Kleinman wrote
This is a valid question. I remind you of one of the theorems of probabilities, that is the sum of the probabilities for all events in an event space is equal to 1. In the simplified model that I am proposing, each amino acid binding event has a probability of 1/40. Increasing the probability for the binding of a particular amino acid will decrease the probability for other(s) amino acid(s). For the first estimate for this calculation I propose that the 1/40 number be used unless you have more accurate estimates for the binding probabilities for particular amino acids.
Brayton wrote
E) whether any shorter proteins may be functional
Kleinman wrote
I haven't specified a particular length for a protein. I have proposed only a length "n" for the protein. You choose the length of the protein when we run the numbers.
Brayton wrote
F) how many variations of the protein may also be functional
Kleinman wrote
If you choose an "n" of 150 which would be representative of hemoglobin then I would allow the assumption of amino acid substitutions at 25 different sites. If you choose "n" of 32 which is the length of the self replicating protein that evolutioists use, allow for variation at 5 different sites.
Brayton wrote
And much more. And all of that assumes the process by which proteins are assembled is entirely random, which does not appear to be justified. Proteins are not formed simply by banging together as many atoms as one has over and over again until a particular protein is produced. Longer proteins evolve from shorter proteins. Unless a probability calculation can somehow include preservation of functional intermediates via natural selection, for example, it cannot possible replicate how proteins are formed in the real world. Thus, such calculations are literally meaningless. Such unreal calculations can be formed to show that practically anything that exists is too improbable. Marshall Berman gives a great example of such reasoning, which I will copy here:
Kleinman wrote
The computation that I am proposing here is for abiogenesis. The only thing I assume is that amino acids are able to join by whatever chemical reactions are available. You choose the length of the shorter protein that evolves to longer proteins and we will start our computation from there. Can we agree that there must be a first protein that starts the process that is not produce by another protein? Are you suggesting that natural selection has effect on inorganic systems? If you do, I would like to know how to measure this force. Again, I remind you that mathematical modeling forces the scientist to enumerate assumptions. If you want to introduce the assumption that proteins are not assembled in a random manner for abiogenesis requires a better argument than what you have made above. If you can convince me that protein formation is not entirely random, show me how and I will attempt to introduce this into the model and see how this affects the probabilities.
Brayton wrote
Let's run a scientific experiment. Go outside and pick up a small rock. The probability of that rock being on that spot on the earth *by chance alone* is roughly the area of the stone divided by the surface area of the earth, or about one chance in 10 to the 18th power (one followed by 18 zeros). If picking up the stone took one second, the probability of such an event occurring at this precise moment over the lifetime of the universe is now even smaller by another factor 10 to the 18th power! This simple event is so incredibly unlikely (essentially zero probability) that one wonders how it could be accomplished! ndeed. If one assumes absolute randomness, virtually anything becomes so improbable as to be folly.
Kleinman wrote
The above paragraph does not represent a scientific experiment or a calculation of probabilities. It is simply a computation of the ratio of the area of a rock to the area of the earth. If you want to paint this an example of computing probabilities, do it in the framework of the theorems of probabilities.
â¢If E are independent events in a sample space S and the probabilities of events E are not equal to zero, then the total probability of events E occurring is the product of their individual probabilities.
â¢P= (E)^n where E is the event and n is the number of independent events.
If you want to consider the probability of picking up a rock before we consider the probability of forming a protein, I will go through the exercise with you but list your assumptions, define your events in your sample space and we can both consider if the model and its assumptions have any validity.
Alan,
Please use blockquotes to indicate when you're quoting something. Your post is unreadable as it is currently formatted. The syntax for blockquotes is [blockquote]the quote[/blockquote], replacing the [ brackets with angle brackets (the ones on the comma and period keys). Use the "preview" feature to see if you've got it right before hitting Post.
Alan,
How would you calculate the probability of getting a Yahtzee during your turn?
Knowing the rules*, would you simply assume that the three throws were independent?
This is an appropriate analogy for what people do who try to calculate the probability of assembling a protein by chance. The rules of molecular evolution don't work that way, so you don't get to make the assumptions you do.
----
*In Yahtzee, the player has three throws of 5 dice in which to roll 5 of a kind. At each throw, the player may retain any number of dice, and throw the remainder. For example, the following would be an example of getting a Yahtzee:
Throw 1: 2,2,3,4,5
(player retains the 2's, throws the other dice)
Throw 2: 2,4,6
(player retains the 2, throws the others)
Throw 3: 2,2
To answer Alan's question, I'm going to refer to the work of my friend Ian Musgrave and paste a portion of his FAQ called Lies, Damned Lies, Statistics and Probability of Abiogenesis Calculations. Hopefully this will all end up looking right. Ian looks specifically at the chances of a single self-replicating peptide coming into existence:
Begin text --------
I will use as an example the "self-replicating" peptide
from the Ghadiri group mentioned above [7]. I could use other examples, such as the
hexanucleotide self-replicator [10], the
SunY self-replicator [24] or the RNA
polymerase described by the Eckland group [12], but for historical continuity with
creationist claims a small peptide is ideal. This peptide
is 32 amino acids long with a sequence of
RMKQLEEKVYELLSKVACLEYEVARLKKVGE and is an enzyme, a peptide
ligase that makes a copy of itself from two 16 amino acid
long subunits. It is also of a size and composition that is
ideally suited to be formed by abiotic peptide synthesis.
The fact that it is a self replicator is an added
irony.
The probability of generating this in successive random
trials is (1/20)32 or 1 chance in 4.29 x
1040. This is much, much more probable than the
1 in 2.04 x 10390 of the standard creationist
"generating carboxypeptidase by chance" scenario, but still
seems absurdly low.
However, there is another side to these probability
estimates, and it hinges on the fact that most of us don't
have a feeling for statistics. When someone tells us that
some event has a one in a million chance of occuring, many
of us expect that one million trials must be undergone
before the said event turns up, but this is
wrong.
Here is a experiment you can do yourself: take a coin,
flip it four times, write down the results, and then do it
again. How many times would you think you had to repeat
this procedure (trial) before you get 4 heads in a row?
Now the probability of 4 heads in a row is is
(1/2)4 or 1 chance in 16: do we have to do 16
trials to get 4 heads (HHHH)? No, in successive experiments
I got 11, 10, 6, 16, 1, 5, and 3 trials before HHHH turned
up. The figure 1 in 16 (or 1 in a million or 1 in
1040) gives the likelihood of an event in a
given trial, but doesn't say where it will occur in
a series. You can flip HHHH on your very first trial
(I did). Even at 1 chance in 4.29 x 1040, a
self-replicator could have turned up surprisingly early.
But there is more.
1 chance in 4.29 x 1040 is still orgulously,
gobsmackingly unlikely; it's hard to cope with this number.
Even with the argument above (you could get it on your very
first trial) most people would say "surely it would still
take more time than the Earth existed to make this
replicator by random methods". Not really; in the above
examples we were examining sequential trials, as if there
was only one protein/DNA/proto-replicator being assembled
per trial. In fact there would be billions of
simultaneous trials as the billions of building
block molecules interacted in the oceans, or on the
thousands of kilometers of shorelines that could provide
catalytic surfaces or templates [2,15].
Let's go back to our example with the coins. Say it
takes a minute to toss the coins 4 times; to generate HHHH
would take on average 8 minutes. Now get 16 friends, each
with a coin, to all flip the coin simultaneously 4 times;
the average time to generate HHHH is now 1 minute. Now try
to flip 6 heads in a row; this has a probability of
(1/2)6 or 1 in 64. This would take half an hour
on average, but go out and recruit 64 people, and you can
flip it in a minute. If you want to flip a sequence with a
chance of 1 in a billion, just recruit the population of
China to flip coins for you, you will have that sequence in
no time flat.
So, if on our prebiotic earth we have a billion peptides
growing simultaneously, that reduces the time taken to
generate our replicator significantly.
Okay, you are looking at that number again, 1 chance in
4.29 x 1040, that's a big number, and
although a billion starting molecules is a lot of
molecules, could we ever get enough molecules to randomly
assemble our first replicator in under half a billion
years?
Yes, one kilogram of the amino acid arginine has
2.85 x 1024 molecules in it (that's well
over a billion billion); a tonne of arginine has 2.85 x
1027 molecules. If you took a semi-trailer load
of each amino acid and dumped it into a medium size lake,
you would have enough molecules to generate our particular
replicator in a few tens of years, given that you can make
55 amino acid long proteins in 1 to 2 weeks [14,16].
So how does this shape up with the prebiotic Earth? On
the early Earth it is likely that the ocean had a volume of
1 x 1024 litres. Given an amino acid
concentration of 1 x 10-6 M (a moderately dilute
soup, see Chyba and Sagan 1992 [23]),
then there are roughly 1 x 1050 potential
starting chains, so that a fair number of efficent peptide
ligases (about 1 x 1031) could be produced in a
under a year, let alone a million years. The
synthesis of primitive self-replicators could happen
relatively rapidly, even given a probability of 1 chance in
4.29 x 1040 (and remember, our replicator could
be synthesized on the very first trial).
Assume that it takes a week to generate a sequence [14,16]. Then the Ghadiri
ligase could be generated in one week, and any cytochrome C
sequence could be generated in a bit over a million years
(along with about half of all possible 101 peptide
sequences, a large proportion of which will be functional
proteins of some sort).
Although I have used the Ghadiri ligase as an example,
as I mentioned above the same calculations can be performed
for the SunY self replicator, or the Ekland RNA polymerase.
I leave this as an exercise for the reader, but the general
conclusion (you can make scads of the things in a short
time) is the same for these oligonucleotides.
To Jeff Hebert and others. Sorry about the format of my message. What I tried to do is address the message Posted by: Ed Brayton May 24, 2006 12:48 PM on a point by point basis by interspersing my responses in Ed Brayton's text. I used "Brayton wrote" and "Kleinman wrote" to delineate our texts. I tried the quotes, brackets and angle brackets and then previewed the text, none of which appeared any better. If my explanation of the format of my Posted by: Alan Kleinman May 24, 2006 03:28 PM message doesn't help make it more intelligible I will rewrite and post the message.
This is the first time I have ever used a blog and welcome any instruction on protocols and formats.
Ed actually has an earlier post about how to use blockquotes:
http://scienceblogs.com/dispatches/2006/01/quoting_in_comments.php
In response to the message Posted by: Matt May 24, 2006 04:33 PM , I first have to admit that I have never played Yahtzee but from Matt's explanation of the game, that the randomness is being reduced by someone with intelligence who chooses which throws to keep. The probability for throwing 5 of a kind from truly random throws would be ((1/6)^5)*(6 possible 5 of a kinds)*(3 throws)=1/432. The addition of an intelligent choice of which throws to keep improves the chances of achieving 5 of a kind. If you insist, I will run the numbers for the probabilities when intelligent choices are made but it should be enough to know that the odds improve when you choose your throws wisely. Consider the case of the not so intelligent Yahtzee player who chooses his throws randomly. The analogy would be that instead of starting with amino acids, one starts with dipeptides. Then the total probability to form a given protein becomes the product of probabilities of forming each of the dipeptides times the probabilities of each of the dipeptide linking to form the protein. I think you will find that this probability will be identical to the linking of the individual amino acids. I actually like Matt's logic. The next time the lottery runs with 5 numbers required to win, I will look for 5 people with 1 winning number on each of their tickets respectively, buy their losing tickets for half price and then turn them in telling the lottery commission I have the 5 winning numbers.
With respects to the message Posted by: Ed Brayton May 24, 2006 05:25 PM , I have read the page posted by Professor Musgrave and have actually emailed him a couple of times. Professor Musgrave makes essentially the same argument that Matt does with his Yahtzee game. Conceptually what this argument comes down is that by selecting a series of more probable events that a highly improbable outcome can be achieved. Take the example of coin tosses that Professor Musgrave presents. In this example he presents the case of tossing 4 heads in a row which has a probability of 1/16. Professor Musgrave tries to short circuit the probabilities by selecting certain outcomes. You can not achieve 8 heads in a row by selecting two sets of 4 heads in a row without violating the principle of random events. If you obtain 2 sets of 4 heads in a row by random tosses, the probability is (1/16)*(1/16)=(1/256) which is the same as the chance of achieving 8 heads in a row by single tosses (1/2)^8=(1/256). If Professor Musgrave wants 8 head tosses, why wait to toss 2 sets of 4 heads in a row. Just toss the coin and keep any heads until he accumulates the desired 8 heads the case has a probability of only 16 throws needed. It's not random and requires an intelligent choice of which tosses to retain but he will get his desired outcome quickly. There are other issues in Professor Musgrave's article that are questionable such as there are 1e+50 potential starting chains. My computation for the number of atoms in the earth is 1.25e+50. Since the majority of the mass of the earth (~95%) is in the form of iron, oxygen, silicon and magnesium, and carbon is not even in the top 10 of the elements composing the earth, this estimate for potential starting chains is at least 3 orders of magnitude to high. There are other issues in Professor Musgrave's article that I find questionable, but I prefer that the debate at this point focus on formation of the first protein. Perhaps one of your readers is a biochemist and could comment of what would be required to produce a protein without a peptide ligase.
So far, this debate seems to be focusing on whether the formation of the first protein occurred completely randomly or there is some type of selection process.
Alan Kleinman writes:
I don't see how you get that from reading what he wrote. What I got was that if you only had 1 person tossing the coins, it would take about 8 minutes to come up with HHHH (although it's possible for that to come up on the very first toss). But if you had 16 people simultaneously doing the flipping experiment, it would take only about 1 minute on average for someone to flip HHHH. Simultaneity has to be accounted for in any such model.
The number of potential combinations can be much higher than the number of particles. If we have 4 particles, there are 24 potential ways which they can combine, assuming a linear arrangement.
There are a number of problems with calculations like these.
It's very very easy to come up with astoundingly looking very large or very small numbers and then compare them to the other numbers like the number of aoms in the universe and pretend like this exercise actually means anything. I could take 6 decks of playing cards, shuffle them well and note the arrangement. Then I could calculate that gee, the probability of exactly that arrangement forming was ca. 1 in 2x10^644, what an astoundingly small probability. And that means what exactly? Nothing by itself. This might be relevent if I'd predicted that arrangement before the fact. Letting the evolutionists pick numbers favourable to them does not fix a poor model. It's your responsibility to supply realistic numbers and a meaningful model if you want to make this argument.
Also, there seems to be some errors in independence. Amino acids are chemically similar, but they also distinct (for instance in steric effects). Ethanol and methanol for example are very similar chemically in many ways, but that doesn't mean both are fun to drink. In this example, this means that the AA's simply don't link up one after another uniformly with no regard for what the last molecule was. Chemistry applies a selection pressure. Indeed, why did amino acids even need to bind all by their lonesome? How do you know they weren't being selected by previously exising and self-replicating RNA chains?
In addition you need to worry about the degeneracy of polypeptides, that a large number of different sequences can accomplish the same task. There are lots of other real world variables you completely ignore. Granted taking every possible effect into consideraion is difficult, but that doesn't mean you can stop with a completly irrelevant random slapping together of amino acids and conclude anything from it.
In order to see how Professor Musgrave is short circuiting the theorem of probability you must go back and study the theorem:
â¢If E are independent events in a sample space S and the probabilities of events E are not equal to zero, then the total probability of events E occurring is the product of their individual probabilities.
â¢PTotal= (E)^n where E is the event and n is the number of independent events.
This theorem says nothing about the rate at which events are done or how many events are done simultaneously, it is only a algebraic equation which allows one compute the number of possible combinations one obtains when random independent events are performed n times. It doesn't matter how fast or slow the sampling is done or how many samplers are taking samples. The computation can be represented in tabular form for the head/tails example as follows for 1, 2, and 3 tosses respectively:
H HH HHH
T TT TTT
- HT HHT
- TH HTH
- - THH
- - TTH
- - THT
- - HTT an so on for more tosses.
Professor Musgrave states it is not very difficult to get 4 heads and if you have lots of people throwing coins very quickly, you can accumulate many sets of 4 heads. What Professor Musgrave does not take into account, at the same time you are accumulating many sets of 4 heads, you are also accumulating the other combinations of heads and tails, HTHT, THHT, and so on in your sample space. When you start to add these combinations of 4-toss units, you are just as likely to connect HTHT with HHHH as HHHH with HHHH in a random independent system.
The probability of connecting any two 4-toss units then is the product of the probabilities of the individual 4-toss units. In this case, the probability of forming any 4-toss unit is (1/2)^4=1/16, for the 8-toss unit made from two 4-toss units, the probability of formation is (1/16)(1/16)=1/256. That is the same probability for forming an 8-toss unit by 8 individual tosses (1/2)^8=1/256.
Perhaps I am misunderstanding Professor Musgrave argument but what I think he is trying to say is that by starting with polypeptides rather than amino acids, we are more likely to obtain the initial crucial protein ligase. If he is doing this, I believe he is defining a model that is neither random nor independent. Perhaps Professor Musgrave would be willing to clarify this point.
Dave S also has a problem with my estimate for the number of atoms in the earth. I presented this number because Professor Musgrave estimated that there are 1e+50 potential starting chains. My computation for the number of atoms in the earth 1.25e+50 was done by looking up the mass of the earth, then looking up the composition of the earth. I then took the percentage of each component and multiplied this value by the total mass of the earth to obtain the mass of each component. I then used the periodic table and Avagadro's number to compute the number of atoms of each component. Carbon is not even listed as one of the main components of the earth. The 11th most common element listed is potassium and represents 0.02% of the earth, and my estimate for the number of atoms of potassium available on earth is 1.75E46 atoms. There is less carbon than potassium. If we assume that every carbon atom is in one of Professor Musgrave's potential starting chains, and there is no carbon in the form of carbon dioxide, methane and any other form, and there is only one carbon in each of his starting chains, his estimate for the number of starting chains is at least 3 orders of magnitude to high.
With respects to self replicating RNA chains, there still needs to be a first RNA chain and the same probability computation can be applied to this system as to the first protein. Evolutionists think that by making the model more complex that it will somehow improve the probabilities. My suggestion to Dave S is to take the simple model I present and make it only slightly more complex by adding the possible event of a non-amino acid molecular group adding to your protein chain. Give that group whatever probability of adding you want. In the simplest case if this group adds with the same probability as an amino acid group then the probability of any particular event becomes (1/41) and the probability of producing any particular protein of length n amino acids becomes (1/41)^n rather than the simpler model which gives a probability of (1/40)^n. Dave S, if you want to have a scientific debate, define your model, list your assumptions and then we can run the numbers and challenge the validity of the model and assumptions.
Alan Kleinman wrote:
This is a very bad argument. The fact that having lots of trials leads to lots of wrong results as well as right results is totally and completely irrelevant if one is judging the odds of getting a right result - all you need is one right result, one self-replicating protein, to start things off. And the number of trials ("samples") makes all the difference in the world. If you're claiming that the odds of getting a single particular combination are one in a billion, but you've got one million trials going on simultaneously every few minutes for 10,000 years, it would be strange if one of those trials didn't get the combination you want. Musgrave gave an actual probability calculation for the production of a specific, real self-reproducting peptide in his FAQ, with realistic parameters in terms of the number of trials and the starting conditions. You've done nothing to detract from it at all other than really bad arguments like the one above.
Alan Kleinman wrote:
Indeed, your model is not independent, as all amino acids do not join all other amino acid with equiprobability. This is simply a matter of basic chemistry as I mentioned in my first post.
And Prof. Musgrave's point seems pretty clear to me. He is assuming a rate to demonstrate that simultaneous parallel trials can construct large numbers of sequences much quicker than sequential single trials. That non-functional sequences are also made is not the point, as Ed has said. The point is that functional sequences are made, and in reasonably short order.
I said nothing whatsover about this number and in fact simply assumed your were correct. What I said was that the number of potential sequences does not need to be equal to or less than the number of particles in the set. There are 52 cards in a deck, but they can potentially be arranged in far more than 52 ways. As far as proteins are concerned, there are many potential sequences that can do the same job as the initially stated target sequence.
But my position is that such calculations are inherently meaningless unless you take into consideration all the relevant real-world variables, reasonable numbers, and sensible assumptions. Even then the output could be absolute nonsense if we miss a crucial variable.
I don't think we have the knowledge base to do that yet. But apparently you do, so it's up to you to demonstrate this.
The reason one constructs a probability model is to get an estimate of how many trials would be required to get a reasonable outcome. Just because Professor Musgrave can throw 4 heads in a row on the first try does not make it reasonable that you can produce a self replicating protein in a reasonable number of trials.
What I am claiming is that the odds of getting a single protein of 32 amino acid length is 1 in 40^32 = 1 in 1.8e+51. The number of carbon atoms on earth is about 1e+47 and since every amino acid has at least 2 carbon atoms. If we assume that every carbon atom is in an amino acid and there is none in methane, carbon dioxide and other molecules, we get an upper limit on the size of the sample space for this simple model.
Consider if every carbon in the sample space combine into 32 amino acid length proteins. This would give 1e+47/64 = 1.5625e+45 proteins produced. Then, 1.8e+51 possible proteins combinations minus 1.5625e+45 possible proteins produced at any one time equals 1.79999e+51 proteins not produced. Let's assume that these 1.5625e+45 decompose back to their constituent amino acids and the process occurs all over again. How many times would this process of making a protein and the protein breaking down to its constituents have to happen in order to sample the space 1.8e+51 times, the probability of getting our initial 32 amino acid protein?
1.8e+51 possible combinations/1.5625e+45 possible 32 amino acid proteins at a time = 1.152e+6. In other words, the entire sample space of 1e+47 carbon atoms would have to be sampled over 1 million times before you would achieve sufficient sampling to meet the probability of 1 in 1.8e+51.
These calculations are based on the following assumptions:
1)Non-enzymatic connection of amino acids readily occurs.
2)All carbon is in amino acid molecules
3)No other chemical reaction with the amino acids occurs.
Every one of the above assumptions are not true but are made in order to get an upper limit on the probabilities. In a more realistic model, the probabilities would become even lower.
See my response above to Ed Brayton. It is Evolutionists that state that life occurred by random chemical processes. Are you backing off of this assumption? I am just applying the theorems or random probabilities to this postulate. Which real world variable do you want me to include? Do you disagree with my calculation for the number of carbon atoms? Scientists are forced to work with the knowledge base they have or do you think that weather prediction computer programs should be abandoned because meteorologist don't have a complete knowledge base?
Really? Provide references to support your assertion that evolutionists believe as you say, that life arose from random chemical processes. I do not believe that is the case. First, evolutionists don't even address this question, since evolution is a theory about life's development, not it's origination. In other words, evolution already assumes the existance of self-replicators, however they arose.
That said, of course origin of life studies is a valid scientific endeavor, but where is your evidence that "evolutionists" claim that that happened by "random chemical processes"?
You keep making meaningless mathematical calculations and then assuming that since you've given the "evolutionists" the benefit of the doubt with your assumptions, that you've proven something.
Please don't compare your gibberish calculations to weather predictions. They at least have the value of actually being fairly accurate predictors (in the short run), because they do include all the major relevant (albeit not all) variables.
To quote Musgrave, these are some of the problems creationist calculations of this sort:
I see nothing in your posts where you address any of these concerns.
I did a google search using the words "evolution", "random", and "chemical" and got 9,520,000 hits. 9,519,999 of those hits were written by intelligent designers. That leaves 1 hit written by an evolutionist. With your luck, you should be able to open the right document on the first try.
1) What is a modern protein????
2) Read my previous posts.
3) Read my previous posts.
4) With your understanding of probability, they must love you in Las Vegas.
5) You still have to get the first enzyme/ribozyme
Alan -
I think it's you who needs a serious tune-up in probability theory here. You're peddling absolute nonsense. And tired derivative nonsense at that.
And I do just fine in the casinos thanks. Blackjack is my main game, but I do like Poker and am trying to learn more.
I am disappointed that Dave S takes my computations as gibberish. I take this as a failure to express myself clearly.
It seems that my assumption that the probabilities for the joining of any given amino acid are all equal at 1/40 leads evolutionists to claim my model is totally invalid. Therefore, I will address this issue.
If the probabilities for any given event are not all equal to (1/40), the equation P=(1/40)^n is no longer applicable. The total probability equation becomes the more general equation,
Total Probability = The product of the individual probabilities of each event
The condition that the sum of the probabilities for each possible event must still equal 1.
Consider the following two examples to see how this affects our expected outcomes.
In the first example, let the probabilities for the events all range close to the (1/40) value between 1/38 to 1/42. The most likely protein 32 amino acids long to be produced would be made of amino acids with 1/38 probabilities. In this case, the total probability of producing this protein is:
P = (1/38)^32 = 1/3.5e+50
In the case of a protein composed of 1/42 probability amino acids, the total probability of producing this protein is:
P = (1/42)^32 = 1/ 8.7e+51
These probabilities represent the upper and lower range of the total probabilities for any protein length 32 amino acids with probabilities for individual events ranging 1/38 to 1/42.
In the second example, let the probability for the joining of one particular amino acid be ½. Imposing this condition requires that the sum of the probabilities for the other 39 amino acids must equal ½. Let the probability for these 39 amino acids be 1/78. The most likely protein 32 amino acids long to be produced would be made of amino acids with ½ probabilities. In this case, the total probability of producing this protein is:
P = (1/2)^32 = 1/ 4,294,967,296
In the case of a protein composed of 1/78 probability amino acids, the total probability of producing this protein is:
P = (1/78)^32 = 1/ 3.5e+60
These probabilities represent the upper and lower range of the total probabilities for any protein length 32 amino acids with probabilities for individual events ranging 1/2 to 1/78.
It is instructive to consider what the physical significance of the second example is. When one says that one particular amino acid is more likely to bind than the rest, one obtains chains of that particular amino acid. Chains of a single amino acid may useful for structural proteins but they do not have enzymatic properties.