Re: Left-handed molecules [was Re: SOC: The Monkey God]

From: Eugene Leitl (
Date: Sun Jan 23 2000 - 23:40:49 MST

John Clark writes:

> That's a pretty small effect, I think the true explanation for the domination
> of L amino acids may be much simpler, pure blind chance, and the fact
> that once a standard is set it's very difficult to change.

Very true. If a chiral autoreplicator evolves in a racemate precursor
pool, it removes its own precursors. Because of spontaneous
racemisation reactions it will hence also drain (some of) the other
moieties, albeit slowly. Of course the metabolism of the arisen
autoreplicator changes the abiotic geochemistry dramatically in
(geologically) very brief time. Also, an early replicator will
self-optimize by evolution, and thus be impossible to catch on by a
newcomer. (Clearly, you cannot have both stereoisomers, since your
overhead doubles).

Taken together these reasons seem to indicate that frozen chance
hypothesis might well be true.

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