Talk:Weasel program

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Richard Dawkins isn't an etiologist. You should think before you start to write.

H. W. Boger

That was a typo; I copied the link from elsewhere, sorry! And BTW, you might try to be helpful (e.g. by fixing the error) instead of being an ass. MFNickster 18:44, 4 January 2006 (UTC)

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[edit] I added a external link which shows what a sham Dawkin's weasel program is

I added a external link which shows what a sham Dawkin's weasel program is. Here it is: Dawkins’ weasel revisited ken 12:08, 11 November 2006 (UTC)kdbuffalo

And I moved it to the bottom of the list and identified the link to show what a sham it is. :-) Cheers, Vsmith 13:17, 11 November 2006 (UTC)

I suppose you take Ted Haggard's side, then? You can fool some of the people all of the time. If you simply stopped long enough to read "A Blind Watchmaker," maybe you'd realize how foolish you are. → R Young {yakłtalk} 07:33, 13 November 2006 (UTC)

[edit] "Criticism of the Critics"

The new Criticism of the Critics section is, in my eyes, misplaced. It doesn't really seem to be about the Weasel Program at all. It refutes criticisms that aren't mentioned in the rest of the article, and the general tone is unencyclopediac. I propose that the section be removed. I will do so in a couple days if there are no objections. Alex Dodge 01:54, 14 November 2006 (UTC)

I would suggest at least mentioning that those who criticize his theories have used fallacies (errors in logic) such as red herring and non sequitirs to attack him. The POV is not balanced as we have criticism of Dawkins yet no criticism of the critics. If you think it's too much, then edit it down to one example.→ R Young {yakłtalk} 03:21, 14 November 2006 (UTC)

Well, I tried to rewrite it, but I realized that I said exactly the same thing as in the previous section. So, I removed the section. Perhaps we can draft a section here and then move it in. In my opinion, the program stands on its own. The only criticism we have of the program in this article (that is has a designed target end point) is discounted in the next paragraph by the statement that this misconstrues the purpose of the program. Alex Dodge 19:33, 14 November 2006 (UTC)

Mr. Dodge, that's not acceptable. First off, we have someone attaching a well-written but fallacious Christian apologist attack. We need to either remove the apologist link, or respond to it in a fair manner. One issue with Wikipedia is to give people information to help them understand things. An apologist attack adds smoke and mirrors. We give them the 'right' to critize the weasel program, yet their own 'arguments' are simply logical fallacies, something that the average reader might not notice. At the very least, the Weasel program is controversial, not because it is wrong, but because some people see it as a threat to their religious beliefs. As such, there is a 'controversy' component. As noted, 'many people' became atheists or left their church after Richard Dawkin's writing. Maybe that's good, maybe that's bad, but it is relevant.→ R Young {yakłtalk} 01:05, 15 November 2006 (UTC)

My apologies. Perhaps you'll reconsider when I've made my points. As I see it, the section as it is addresses several logical fallacies which have been used to try to discredit evolution. The quotes and the responses don't particularly have anything to do with the Weasel program, specifically. I see now the link you're talking about. I don't understand why it's in the article, and I don't see the need to respond to it. I think the link (as well as the other links to similar silliness) could be safely removed, which removes the need for the section.

I had removed the section, as I said, so that it could be revised in the talk page if it was decided that it needed to exist. As it is, it reads more like a defensive rant than an encyclopedia article. I would try to rewrite it myself, but I'm not yet convinced it's a valid section. If it is included, it will need to be written carefully, with a clear goal and a clear argument.Alex Dodge 08:38, 15 November 2006 (UTC)

I would prefer to delete the apologist link as inappropriate. → R Young {yakłtalk} 08:55, 15 November 2006 (UTC)

It is done. Does this agree with you? Alex Dodge 11:07, 15 November 2006 (UTC)

[edit] Transcription error?

It looks as though the fourth character of the first line of sample output is missing. I could of course replace it with any random letter (except H), but I’m not sure whether the sample is quoted from the book or generated for this page. -Ahruman 01:01, 9 December 2006 (UTC)

There's a comment in that section which says "Note: first generation is 27 characters, but it is verbatim as Dawkins gave it in the book. Perhaps the first or last character is a space." I dug out the book and verified that the examples match Dawkins's text. MFNickster 02:13, 9 December 2006 (UTC)

[edit] More Realistic Weasel Program?

I was tinkering with the weasel program a bit and had a few insights, which I offer here on the basis that they might provide useful angles to this article. I figured out that it could be made into a more realistic representation of Darwinian evolution by natural selection if, instead of hunting for a given phrase, it used the rules of language to simply come up with any possible phrase that made sense.

This being difficult to do, to say the least, a workable compromise would be to give the program a text file, specify a string of a particular length, and then allow the program to go off on its own and duplicate some unspecified string in the file. This would not be very hard to do and it might be kind of fun ...

... but the really interesting thing is that it would be a waste of time, since from the point of view of the user it is hard to believe that it would take any longer to converge on a solution (in terms of generations, ignoring the greater computing overhead for each generation). In fact, it would probably be faster, since having more strings as possible targets gives more chances for a random letter selection to come up with a match.

All the weasel program was ever supposed to do, as anyone who understands it knows, was show that the "monkeys & typewriters" notion of Darwinian evolution was unrealistic -- a "monkeys" or "saltationist" program would just try to pick strings at random until it got a match, which would take a *very* long time, while the weasel program quickly and relentlessly converges to a solution.

That provides the "light bulb going on in the head" revelation to show a person who's hung up on (but not clinging to) the "monkeys & typewriters" scenario what the real story is: "My weasel takes out your monkey."

Incidentally, there is also the notion -- the "Gish fallacy", after its best-known advocate, Duane Gish -- that since the weasel program (or other evolutionary computer simulations in general) is a program built by a designer, it demonstrates that organisms in the real world must have been made by a designer as well. I realize that nobody with sense fails to laugh at this, it being a confusion of a model with the thing it's modeling, but I offer as a comparison that it's like claiming that since a toy robot panda is built in a factory in China, then a real panda must be made at the same factory -- or like the logic used in cartoons in which a tunnel is painted into the side of a mountain and a train roars out. (By the same logic a computer model of a tornado would demonstrate that tornados were designed.)

One comment: if I am an admirer of Dawkins for his knowledge of evolutionary science, that does not correspondend to *any* endorsement of his views on, uh, other subjects. MrG 4.225.211.216 20:55, 8 June 2007 (UTC)

[edit] Dodgy bits

In the article, it says:

Dawkins then goes on to show that a process of cumulative selection can take far fewer steps to reach any given target. He refines the program to preserve "favorable" combinations (or "hits") and to allow the remaining letters in the sequence to be replaced. In Dawkins's words:
We again use our computer monkey, but with a crucial difference in its program. It again begins by choosing a random sequence of 28 letters, just as before ... it duplicates it repeatedly, but with a certain chance of random error – 'mutation' – in the copying. The computer examines the mutant nonsense phrases, the 'progeny' of the original phrase, and chooses the one which, however slightly, most resembles the target phrase, METHINKS IT IS LIKE A WEASEL.

Notice that the statement preceding the quote is not supported by the quote itself. What is at issue is whether "weasel" locks in place correct letters as it goes along. Antievolution advocates William Dembski and Robert Marks call that "partitioned search". If one reads "The Blind Watchmaker" carefully, one will see that there is no mention of such a procedure in operation. I corresponded with Richard Dawkins a little over seven years ago to verify that he had never described such a mechanism for "weasel", which he confirmed.

This is simple to fix in the article: strike the second sentence, like so:

Dawkins then goes on to show that a process of cumulative selection can take far fewer steps to reach any given target. He refines the program to preserve "favorable" combinations (or "hits") and to allow the remaining letters in the sequence to be replaced. In Dawkins's words:

And that will do the trick. Unless someone can point to a verifiable source for the assertion that correct characters are retained by a specific mechanism in the program, I will alter this later on, unless someone goes ahead and makes the change. --Wesley R. Elsberry 20:14, 16 October 2007 (UTC)

I've modified the article to bring it into conformation with what Dawkins actually described.

In looking over the remainder, though, I noticed:

"Some philosophers of science have criticized the example as overly simplistic[citation needed],"

Well, the first such citation would be "Richard Dawkins, 1986, The Blind Watchmaker", who discussed a number of points on which "weasel" fails to be a satisfactory emulation of the biological situation. In fact, Dawkins' original discussion is usually far superior to that of various "critics" who followed him. The antievolution crowd in particular seems to have a thing for generating irony as they "introduce" what they claim to be criticisms of "weasel", without apparently having read Dawkins' own self-critique. It should be noted in the article that Dawkins was well aware of the simplistic nature of the program, and that was why he specifically limited his discussion of its utility to the purpose of distinguishing between "single-step evolution" and "cumulative evolution". Again, if there's no substantive disagreement on this point, I will modify the article a bit later on. --Wesley R. Elsberry 14:19, 31 October 2007 (UTC)

Identification of beneficial change in biology?

The program is a vivid demonstration that the preservation of small changes in an evolving string of characters (or genes) can produce meaningful combinations in a relatively short time, as long as there is some mechanism to identify and preserve desirable changes while allowing undesirable changes to be removed or replaced. This is intended to serve as an analogy to natural selection's action on randomly mutating genomes, with the "desirability" (or fitness) of any given change being determined by the organism's interaction with its environment.

The struck-out words correspond to an edit I made on the article, with this comment: "No necessity for identification of beneficial change, therefore removed."

This change was reverted by MFNickster with this comment: "(rv - in the case of the Weasel program, yes, comparing the phrase to a target amounts to identifying such improvements)"

I think it should be clear that the stated reason for the revert is unjustified. 1. The section in question is not specifically about "weasel"; it is about biology as well, and there is no "identification" of beneficial parts. 2. Even in "weasel", there is no "identification" of the part that conferred benefit. The string match does not cause particular desirable changes of the "genome" to be preserved, contra the article's statement. This constitutes an error in the article, and should be removed expeditiously. --Wesley R. Elsberry (talk) 05:10, 27 November 2007 (UTC)

Hi, I take your point, but unfortunately, without having Dawkins's code or something like it, it's impossible to tell how the comparison was done. However, Dawkins did state that the selection pressure was toward the phrase which "most resembled - however slightly - the target phrase." From this, I think we can infer that a comparison is done which would identify matching characters as "increased fitness" and non-matching characters as "decreased fitness." In this context, "desirable" would have to mean matching characters, would it not? MFNickster (talk) 06:11, 27 November 2007 (UTC)
Addition: You are correct that the phrase does not refer solely to the program, although when I wrote the sentence I failed to notice the confusion of the two. Maybe we can find a phrasing which is technically correct, but gets the point across that the mechanism is one which selects for fitness (or "desirability") in the organism's environment. MFNickster (talk) 06:19, 27 November 2007 (UTC)
Getting rid of "identify and" is technically correct phrasing.
It seems to me that "identify" is WP:OR. It certainly doesn't ring a bell as to being part of what Dawkins described in "The Blind Watchmaker" as any necessary part of the underlying biology, nor do I recall him using the term in describing "weasel". It doesn't matter that we don't have Dawkins' code; unless you can provide WP:RS for the wording involving "identify", removing it is the right thing to do. --Wesley R. Elsberry (talk) 13:40, 27 November 2007 (UTC)

Okay, I have made another edit which I believe is closer to what I was trying to describe. In re-reading the passage in the book, I noted that Dawkins was careful to avoid such loaded words as "desirable," "beneficial," "improved," etc. Let me know what you think. MFNickster (talk) 16:38, 27 November 2007 (UTC)

The new edit is (1) less clear than the edit I proposed for the old text and (2) incorporates an additional quote from Dawkins which is, unless I am utterly mistaken in my recall, addressing a different program, his "biomorphs" example.
Something that I feel is missing here is an appreciation for a critical aspect of Dawkins's argument: evaluation of the fitness of whole phenotypes can cause the preservation and differential propagation of individual genes. Not appreciating this was expressed earlier in the article falsely claiming that individual changes were locked in and not subject to mutation as "weasel" found new matches at the character level. This problem carried over into the section now at issue with that "identify desirable changes" phrasing. In the current edit, one can still see its influence in "select cumulative changes". This is problematic in that "cumulative change" is not distinguishable from simple "change". I think the current edit does not adequately distinguish an outcome, the general and usual preservation of cumulative change, with a mechanism to accomplish that. --Wesley R. Elsberry (talk) 16:10, 28 November 2007 (UTC)
Yes, the additional quote refers to the biomorph example, but its point applies to 'Weasel' as well. They are both examples of artificial selection. I found it clearer to keep the context on 'Weasel' rather than add additional description to compare 'Weasel' and the biomorphs. The only real difference is that in 'Weasel' the selection is determined once at the beginning rather than incrementally each generation. It probably should be placed in proper context, though, or be removed.
I think my recent edit is clearer than the previous version, because more specific about the circumstances that apply in each case, but on re-examining the chapter in question I think we can re-write the section to follow from Dawkins's text without relying on too much interpretation. The main points I'm trying to get across here are:
  • The example doesn't have implications for biology beyond the demonstration of cumulative vs. random "single-step" selection - Dawkins intended it only to refute the argument that organic molecules are too complex to have arisen by chance.
  • The program does rely on a human-chosen 'target', but this is irrelevant - the point is that cumulative selection works whether the selection process is natural or artificial.
  • The selection being done in 'Weasel' is not a demonstration of selection by phenotype. The biomorph program is a better model of that process, because the user never sees the 'genes' that grow the biomorh. In 'Weasel' the programmer selects a target genome, not a phenotype.
Regarding your other points, my misunderstanding of how 'Weasel' works is due to my memory of an example on another site which gave an interactive demonstration of a Weasel-type program - unfortunately, the author did exactly what I described, "locking in" each change that matched the target, and I had forgotten that Dawkins never said that this was what his own program did. I regret not verifying that.
Cumulative change would be indistinguishable from random change if the mutation rate were high enough - each child string would no longer resemble its parent much if at all, which would effectively scramble the string each generation and the selection process would fail to reach the target. I don't believe Dawkins mentions this in the text, though. MFNickster 15:43, 30 November 2007 (UTC)
No, I don't recall Dawkins mentioning high mutation rates in his text. The most likely reason being that very high mutation rates are rather unlike the biology. I did write to the authors of a website featuring an erroneous "weasel" program recently, telling them:
If the mutation rate is increased, the search takes an increasing number of tries, until in the limit of constant replacement at every position the algorithm is indistinguishable from blind search. The "partitioned search" method, though, is relatively insensitive to mutation rate change, and will converge even with a 100% mutation rate.
Basing the description more closely upon the original text sounds like a good idea.
Leaving the quote about biomorphs in the "weasel" article without an explicit statement that Dawkins is talking about a different program is a bad idea. My $0.02. --Wesley R. Elsberry (talk) 04:24, 13 December 2007 (UTC)