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Author
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Topic: Meta-Strachan: What, if anything, is at stake?
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yersinia
Member
Member # 324
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posted 05. July 2003 17:16
I was reading recent comments on the Schneider/Strachan discussion, and it suddenly occurred to me that the arguments of both authors are a bit beside the point.
To wit, the mod posted,
quote:
Well, if you take notice, Strachan has taken Schneider to task, and it is far from clear whether Schneider has shown much of anything. [...] He's got a Ph.D. in the field and is an expert in both genetic algorithms and neural networks. He deserves to be taken seriously.
And similarly Micah or someone at ISCID went to the trouble of putting Strachan's modified METHINKS-type simulation up on the web, here:
http://www.iscid.org/vignere/vete.php
http://www.iscid.org/vignere/vignere-text-evolution.php
...so clearly someone thinks that Schneider's paper draws a conclusion that is worth debating.
Here is my question: isn't the central question "Can evolution increase 'information' in the genome?" or something similar?
It seems to me that, if this is the question that people are interested in, Schneider's simulation is pretty small potatos. At most it was a modified 1984 computer program that showed that variation and selection for binding strength could produce strong binding, with the interesting side-conclusion that binding strength has an interesting information-theoretic property such that information measures Rfreq and Rseq ended up matching. This information amounted to a few bits per binding site. Schneider threw into his paper some incindiary anti-ID remarks and has similarly promoted the paper, so it has gained attention in ID circles.
But really, is the proposition "evolution can increase 'information' in the genome?" really in any doubt at all? I mean, Dembski himself (see Intelligent Design, for example), argues that chance alone can produce small amounts of specified information, and that selection can preserve these small amounts. The only reason that this process can't build up to produce large amount of specified information, i.e. complex specified information (CSI), is basically irreducible complexity (IC).
Perhaps people will cite Dembski's supposed "Law of Conservation of Information", but that is similarly said to apply only to CSI, not mere SI. One could additionally argue that the information that increases in genomes is gathered from the environment (so no "conservation" is being violated) although I think that this is a fairly confused position: IMO information can't really be said to "exist" until it is encoded somewhere.
Apart from Dembski's admission, we have reams of evidence in biology for the creation of new genes by duplication and modification of old genes, which I think would have to be intepreted as increases in information on any reasonable definition. Behe similarly concedes such processes (e.g. hemoglobin), he just objects when it comes to IC.
The only people would I can think of who've really asserted that evolution really can't increase information in the genome are Phil Johnson and creationists such as Spetner.
So, what's the big deal?
Cross-refs:
An Evaluation of "Ev"
http://www.iscid.org/boards/ubb-get_topic-f-6-t-000384.html
Mod quote:
http://www.iscid.org/boards/ubb-get_topic-f-18-t-000001-p-19.html
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peter borger
Member
Member # 722
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posted 07. July 2003 02:58
quote:
Apart from Dembski's admission, we have reams of evidence in biology for the creation of new genes by duplication and modification of old genes,
Do you mean observed duplications and divergence of the duplicate into a new gene? If so please provide a reference.
Or do you mean the observation of gene families preexisting in the genome for finetuning gene expression (transcription and translation) and that you assume have their origin in gene duplication?
best wishes
PB
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Rompecabezas
Member
Member # 814
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posted 07. July 2003 15:17
Information isn’t the best analogy to genetic material in any case. I realize the metaphor is irresistable to many authors, and like most analogies it helps laymen like myself visualize a complicated concept.
Information in its technical sense is always complex and specified, and refers to the most efficient decrease in prior uncertainty. Our shorthand definition of information as meaning ‘data’ leads inexorably to computer metaphors, and no less an authority than Bill Gates has allegedly gone on record as praising DNA for its similarity to a computer program. This familiar confusion of man-made design and natural design can be made to serve purposes beyond mere visualization. It may be more convenient for some if people think that DNA is something that it’s not. A computer program contains the information necessary to execute a function or series of functions. The genome does not contain the information necessary to build an organism. It contains chemical templates for building proteins that an organism uses in its functions. An actual nucleotide sequence (the ‘data’) doesn’t contain any more or less information than any other of equal length.
I don’t think a more realistic assessment of the hereditary mechanism we share with all other organisms on Earth robs it of its acknowledged power to stagger the imagination.
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Mark
Member
Member # 888
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posted 23. August 2003 15:22
Romp referred to information as a "metaphor" for genetic material.
This reminded me of comments made by George C. Williams, which seem to be on point.
quote:
Evolutionary bioligists have failed to realize that they work with two more or less incommensurable domains: that of information and that of matter. . . . These two domains can never be brought together in any kind of sense usually implied the term "reductionism." . . . The gene is a package of information, not an object. The pattern of base pairs in a DNA molecule specifies the gene. But the DNA molecule is the medium, it's not the message. Maintaining this distinction between the medium and the message is absolutely indispensable to clarity of thought about evolution."
And further:
quote:
You can speak of galaxies and particles of dust in the same terms, because they both have mass and charge and length and width. You can't do that with information and matter. Information doesn't have mass or charge or length in millimeters. Likewise, matter doesn't have bytes. . . . This dearth of shared descriptors makes matter and information two separate domains of existence, which have to be discussed separately, in their own terms.
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Rex Kerr
Member
Member # 632
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posted 24. August 2003 23:54
Williams sounds rather confused to me.
Mass doesn't have coulombs or millimeters or candelas. Charge doesn't have grams or millimeters or candelas. Length doesn't have grams or coulombs or candelas. (etc.)
Matter has many properties. Some of them are applicable at any scale (e.g. relativistc mass), and some are only applicable in numbers (e.g. information). You can't have information without matter (except in the abstract) any more than you can have mass without matter (which you can also do in the abstract if you want).
Information content is an important aspect of matter that is worth studying when it comes to evolutionary biology. But to say information and matter occupy "incommensurable domains" seems both bizarre and counterproductive.
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