Re: Where does information come from?


John Wilkins wrote:
r norman <NotMyRealEmail@xxxxxxxxxxxx> wrote:

On Sat, 03 Jun 2006 09:25:00 +1000, John Wilkins <john@xxxxxxxxxxxxx>
wrote:

john.19071969@xxxxxxxxx wrote:
John Wilkins wrote:

DNA transcription is a simple chemical reaction mediated by structures
in the cell. Unless *every* chemical reaction is "information
transfer", the expression of DNA carries no information, only causal
regularities.

*Dretske is a bit more restrictive here - he requires that the
signalling is 100% reliable. I do not.

The problem is one of language. The biochemists used the word "code" to
describe the sequences of bases in DNA. Yet, DNA is not really a code,
it is a molecule that serves as a template catalyzes the formation of
lots of different types of molecules.

The idea of a "DNA code" is an analogy, like using the analogy of a
water pipe in describing a blood vessel. Ultimately, both metaphors
fail when taken to their extreme.

Thanks, John. *Somebody* understands what I'm trying to say. This is a
sign I'm not wholly off with the reductionist fairies, I guess...

While away and using Google, I couldn't browse through the messages as
thoroughly as I would have like.

John Wilkins, are you agreeing with this other John nonsense in saying
that blood vessels cannot be described as pipes? Are you truly
serious in saying that the DNA sequence can not truly be considered a
code? The fact is that the DNA sequence contains in a very abstract
and indirect form (a "coded" form) the 'information' (yes, I used that
word deliberately) necessary in producing a functioning cell and
organism. The information must be interpreted properly, as must all
information, which requires a functional cellular system of gene
regulation, transcription, and translation. And every step of the way
is a physical-chemical process. Still, alterations in the sequence
produce well known and described alterations in the appearance of the
resulting organism, exactly as if the DNA sequence was "coding" for
that appearance (or for other features that result in the appearance
being produced as a consequent side effect).

You can describe blood vessels as pipes. Of course, they aren't made
from any of the usual materials as pipes, and they aren't connected in
segments, and they don't have the turbulence problems of pipes, and they
aren't manufactured, but sure, there is a *metaphorical* sense in which
they are pipes. And we can understand, when we use the term "pipe" that
there is one, and only one, sense in which that metaphor carries meaning
- blood vessels allow the flow of fluids. But now suppose that someone
tries to argue that blood vessels, because they are pipes, *are* made of
steel, ceramics and plastic, and they come in different standard sizes,
and lengths, are assembled in pieces, using some kind of cement to joing
the gaps, and they have the same turbulence problems as a right angle
joint does in the mains water supply of a house. You'd suggest they were
over-extending the metaphor, wouldn't you?

Now consider what sorts of illicit analogies people make about
information. From there being a genetic "code", you get people saying
genes are algorithms, programs, are meaningful, represent the
environment of selection, and so forth. If all you mean by "code" is
that genes cause the expression of certain molecular building blocks,
then to that extent the metaphor is meaningful. And even that is under
attack now since genes appear to be little more than standing waves of
probability of expression. But the illicit claims cause no end of
trouble in thinking about biological processes, and the creationist
canards are only the extreme end of that trouble.

There are a number of putative meanings for "genes", ranging from the
almost tautological claim that genes are hereditable features (Mendelian
genes; the ratio of assortment and heredity is not tautological, of
course) through to the open reading frame conception and variants
(edited ORF, and so on). Which ones "carry" the information? What *is*
the information? And does it have any causal properties that are not
reducible to a description of the causal processes of expression and
replication?

If you wish to call this nonsense, then we are at an impasse. I think
the nonsense lies in ascribing intentional properties to molecules. So
there's little more to be said.

Of course, even in a conventional worldview informed by science and
atheism, "meaning" is only a value system that we choose to impose on a
mostly-unthinking environment around us. But it doesn't seem to me to
stretch the metaphor too much to say that a gene (in its physical
context, in a living cell, with lots of other genes) is a coded
document which has a meaning (in that physical context), which is the
physical expression of that gene - what would be different if the gene
was different or absent. Now of course it is also often very difficult
fully to understand the expression of one gene. But this is true of
some of our own texts, too - they can have meaning which an author did
not consiously introduce, or which are not connected to the author at
all; very subtle effects, hard to see. And it does /happen/ that
living cells may have genes that are different or are added or removed,
and the differences that this makes in the life of the cell may be of
very great interest to us - everyone will recognise cancer as an
example. So formal philosophy may be out of step with actual human
concerns in this respect.

.

Relevant Pages

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  • Re: Where does information come from?
    ... describe the sequences of bases in DNA. ... You can describe blood vessels as pipes. ... there is one, and only one, sense in which that metaphor carries meaning ... that genes cause the expression of certain molecular building blocks, ...
    (talk.origins)