Re: [asa] Information and knowledge

On 4/14/07, Iain Strachan <igd.strachan@gmail.com> wrote:
>
>
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> So I would argue that digital IS necessary for the conservation of
> genetic messages.
>

Let me correct an impression that I have created to state that there are
legitimate applications of communication theory within biology. You just
have to be real careful because it is so easy to misapply it. Communication
theory does explain why DNA replication works so well. The fact that the
amino acids only pair with one other one in the double helix sets up a kind
of even parity Hamming code. The other area where communication theory is
helpful is looking at error rates and genetic drift. Since the copies are
not perfect just near perfect the genome drifts at a predictable rate. This
helps us date the cladistics. Comparative genomics uses this fact to detect
natural selection. If we have a change that doesn't fit the drift frequency
and is also functional we can safely conclude that there has been positive
selection going on. This is because most coding sections of the genome are
conserved again because the copying mechanism is so good and if they change
they usually produce negative results. This week's Science has a good
example of this with the three-way comparison of human, chimp, and macaque
monkey genomes providing yet more evidence of not only common descent but
also natural selection. See here: http://www.sciencemag.org/sciext/macaque/

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Received on Sat Apr 14 13:10:25 2007