Re: Information: Brad's reply (was Information: a very

Greg Billock (billgr@cco.caltech.edu)
Thu, 25 Jun 1998 08:41:39 -0700 (PDT)

Brian Harper:

>
> I don't know what to say except to repeat what Yockey says in
> his book. In section 5.1.3 he states that the DNA-mRNA-protein
> system is discrete, memoryless and unconstrained. These terms
> are defined as follows:

Is Yockey talking just about the decoding context, where codons
are mapped to amino acids? Surely he doesn't mean that there
are no intersymbol dependencies in DNA when seen as a big part
of the schematic for a system which has to be alive.

> this. First you note that you are unable to predict an
> amino acid in the sequence knowing what the neighboring
> amino acids are. From this you conclude that the sequence
> is random and from this that it must be due to chance.
> A clever argument the refutation of which is not particularly
> obvious. Yockey's refutation is simply that the inability

Perhaps I'm not getting it, but the argument seems to ignore
that there can be long-range intersymbol dependencies, which
is exactly what we would expect in DNA (as opposed to short-range
dependencies, which are muffled by code redundancy). Did Monod
and Yockey both get confused by comparing DNA to human languages,
where intersymbol dependence tends to go monotonically downwards
(and fairly sharply) with symbol separation?

-Greg