Re: Evolution increases the computational ability of organisms.
- From: "John W Edser" <edser@xxxxxxxxxxxxxx>
- Date: Fri, 5 Oct 2007 13:28:32 -0400 (EDT)
Guy A Hoelzer <hoelzer@xxxxxxx> wrote:-
"Guy A Hoelzer" <hoelzer@xxxxxxx> wrote in message
Here are a few words about my view of information, for what they are
worth.
Information exists in the relations among physical things. It is not
a
physical thing itself. It can manifest as a potential (a contrast, a
gradient of change, ...) or as a flow (communication between
entities).
JE:-
Hello Guy,
I cannot understand how (but I do understand why) information can be
viewed
as "not a physical thing itself" using either a "potential (a
contrast,
a
gradient of change, ...)" or "as a flow (communication between
entities)".
For the first, something physical has to be able change just to allow a
proposed potential change and for the second, something physical has to
carry the communication. It appears to me that these things remain as
mystical as Newton's proposed gravitational force acting at a distance
appeared before Einstein.
Hi John,
Good comments.
First, I should add to my previous, brief comment, by saying that
structure
itself represents information because structure exists as a relationship
among the components of the structured whole.
You probably already know this, but I am more hopeful than you about our
opportunity to demystify information in the context of complex,
dynamical,
dissipative systems theory.
JE:-
Hi Guy,
I agree that what we call "structure" represents information about the
relationship of the components of what we can only assume to be one
whole.
From my perspective a "structured whole" concept cannot exist if the
information flowing between components remains reversible. As you
probably
know I use the revised central dogma of biochemistry to illustrate this
point. The structure we term "one gene" (which alone contains "genetic"
information) cannot exist if the polypeptides that they code for are able
to
act as a coding template for DNA/RNA (which of course they do not). Only
a
reversible association between DNA/RNA exists but a much more critical
non
reversible information relationship is established between DNA/RNA and
the
polypeptides which have to be assembled into proteins to build bodies.
Without this non reversible logical linkage between DNA/RNA and the
polypeptides that they code for requiring all genetic information to flow
the one way: from the genetic material to somewhere else and not the
reverse, a "structured whole" cannot exist for genetics. This can be
illustrated by the most concise criticism of Lamarckian inheritance that
I
know of which argued that if the non reversible coding relationship
between
DNA/RNA and the polypeptides that they code for was reversible allowing
acquired characters to be passed back to the genetic material then
evolution
by natural selection would become impossible. IMHO it is the one way flow
of
information that best demystifies "complex, dynamical, dissipative
systems".
John,
I am not entirely comfortable with the way you articulate this argument,
but
I think we agree on the bottom line in the context of dissipative systems.
These systems, as originally described by Prigogine, are thermodynamic
machines. Therefore, they are fundamentally unidirectional in their
effects
(always generating a net increase in entropy). Energy (information)
enters
a dissipative system, is processed and taxed (to do the work of the
system)
as it flows through the system, and is released back into the environment
in
degraded form (reduced potential to support work). Does this sort of
thermodynamic directionality satisfy your notion of irreversibility?
JE:-
Hello Guy,
I don't think so. This is because entropy increases and decreases within a
biased equilibrium such that only net entropy increases over time. Imagine
if genetic information did the same thing, i.e. DNA/RNA and polypeptides
could move genetic information either way so that only a biased equilibrium
event allowed a net flow of information from the DNA/RNA to the polypeptide.
The result would be chaotic.
More generally, any reasonable proposition requires the notion of an
entirely non reversible flow of information just to enable the proposition
to be understood. For example selective information, like genetic
information cannot flow both ways within the revised central dogma and
remain understood because selective information flows in the _opposite
direction_ to genetic information: from the polypeptide to the gene. There
can be no flow back of either category of information otherwise we could not
be able to differentiate selective information from genetic information.
Regards,
John Edser
Independent Researcher
edser@xxxxxxxxxxxxxx
.
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