N.Wells
Posts: 1836 Joined: Oct. 2005
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DNA is not symbolic. It is a chemical, not a code (or if it is a code, so is water.) Strictly speaking it is not coded, nor is it decoded or interpreted. It is a chemical that interacts chemically, which is not true of any other known codes. (Unless you want to make an issue of smoke signallers coughing.......? :) )
From http://www.antievolution.org/cgi-bin....;t=9614 Quote | The way a computer code works is that the exact sequence of the code - the precise order of the binary 1s and 0s - spells out exactly what operations the computer must perform. But in genetics, the sequence is only part of the picture. Just as important are genetic regulatory networks - which genes are turned on at what times and in combination with which other genes. Phenotypes are not simply the result of particular gene sequences but the result of specific gene-gene (or gene network-gene network) interactions.
But DNA bears little relation to a "code" in a more fundamental way. Consider exactly what a "code" is. A code is a system of arbitrary symbols used to represent ideas and objects. In a sense, language itself is a "code"; the symbol "dog" represents that furry tetrapod with a waggly tail, for example. In a code, the symbols themselves have no inherent meaning. The letter "d" is meaningless by itself, as are the letters "o" and "g". It is only in combination that they derive meaning, and their meaning is derived from the idea that they represent. Furthermore, they only have meaning because we give them meaning. "Dog" is merely the label we apply to Fido; in a universe without sentient beings, "dog" would be meaningless. DNA does not fit this description at all. DNA is not arbitrary in any way; each letter of the genetic "code" is an actual biological compound. ACCGTCGA might be the gene for determining how long your toe hair is, but unlike a code, A, C, T and G each have their own non-arbitrary meaning. And this meaning exists independently of human sentience - the sequence of nucleotides does not have meaning only because we give it meaning. It would have meaning even if humans didn't exist at all.
What DNA is, is a polymeric chemical that follows a dynamic chemical process, governed by universal physical rules. It is only a "code" in the same sense that nuclear fusion is a "code" for how stars produce light |
From http://www.talkorigins.org/indexcc....80.html Quote | The genetic code is not a true code; it is more of a cypher. DNA is a sequence of four different bases (denoted A, C, G, and T) along a backbone. When DNA gets translated to protein, triplets of bases (codons) get converted sequentially to the amino acids that make up the protein, with some codons acting as a "stop" marker. The mapping from codon to amino acid is arbitrary (not completely arbitrary, but close enough for purposes of argument). However, that one mapping step -- from 64 possible codons to 20 amino acids and a stop signal -- is the only arbitrariness in the genetic code. The protein itself is a physical object whose function is determined by its physical properties.
Furthermore, DNA gets used for more than making proteins. Much DNA is transcribed directly to functional RNA. Other DNA acts to regulate genetic processes. The physical properties of the DNA and RNA, not any arbitrary meanings, determine how they act.
An essential property of language is that any word can refer to any object. That is not true in genetics. The genetic code which maps codons to proteins could be changed, but doing so would change the meaning of all sequences that code for proteins, and it could not create arbitrary new meanings for all DNA sequences. Genetics is not true language.
The word frequencies of all natural languages follow a power law (Zipf's Law). DNA does not follow this pattern (Tsonis et al. 1997).
Language, although symbolic, is still material. For a word to have meaning, the link between the word and its meaning has to be recorded somewhere, usually in people's brains, books, and/or computer memories. Without this material manifestation, language cannot work. |
DNA is understandable as a specialized alternative to RNA, and RNA is simultaneously the information, the tools to make stuff, and the material out of which both the tools and the structures are made. DNA simply holds the information and hands the rest of the capabilities off to proteins.
I mentioned "DNA as blueprints" not because you said it but because it is another common and partially useful analogy for DNA that can similarly derail horrendously when one extends the analogy to areas where it does not apply.
Quote | You need to explain how those huge amounts of information originated. You guys claim we get those by successive random mutation, I want to see the possibility of that modelled; because to me when you're dealing with that amount of variability, it's completely impossible. | Duplication and mutation create new "information", and so does recombination (because so many developmental outcomes result from chemical interactions between gene products rather than just the presence or absence of individual genes - yet another reason why DNA is not just a code). Also, there is no single "target", but rather a selection of what works well enough or better than the alternatives in terms of resultant numbers of offspring, so simplistic probability calculations don't apply, and neither do simplistic life-or-death dichotomies.
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