On 03/19/13 14:41, Jacob Keller wrote:
I don't understand this argument, as it would apply equally to all
features of the theoretical LUCA (protein and DNA sequences, etc). To
make it logically sound, I think you have either to include some kind
of super-high boundary to getting to other possible conventions (you
probably imply this) or, as I have suggested, it may be a particularly
good, if not the best, solution (a global minimum, one might say). The
first hypothesis is similar to the QWERTY keyboard, which is cemented
in place by many factors, whereas the second is more "survival of the
fittest."
It would not be a safe idea to assume that LUCA was a single cell with a
single chromosome (i.e. like a modern bacterium.) It would also not be
safe to assume that viruses and horizontal gene transfer were not around
at that time.
As I mentioned privately, I think the relevant slogan would be "winner
take all" rather than "survival of the fittest."
Another possible explanation for having a recognition tag at the
beginning of each transcribed gene: to distinguish between host and
virus. This does not imply that Met has any specific advantage over any
any other tag which might have been chosen.
--
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All Things Serve the Beam
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David J. Schuller
modern man in a post-modern world
MacCHESS, Cornell University
[email protected]
