metabolism & energy autonomy

Dear Norbert:

Thank you for that clarification of your concept of metabolism. I guess
the differences between us to remain pretty deep, after all.

I don't like to argue about the meanings of words, but "metabolism"
after all means "anabolism" & "catabolism", that is, the building up and
breaking down of polymers. Nothing remotely like this is going on in a
hurricane, I think you will agree. So, isn't it misleading to take a
word with a well-established meaning in biology, and apply it to a
non-biological system, when there is not even a real analogy between the
dynamics of the two cases?

But that aside, I see the more important difference in the phenomenon of
energy autonomy. A hurricane is an open system, yes, but it is a slave
to the local thermodynamic gradients in its vicinity. It spontaneously
tries to resist its own destruction to some extent, but that extent is
extremely limited precisely due to the tight thermodynamic coupling to
its surround. I think the essence of life is the fact that living things
are NOT tightly coupled thermodynamicall to their surrounds in the same
way. Rather, they are buffered and have internal energy stores which
they can use selectively to work against local gradients (e.g., by
moving ions against osmotic gradients). Think, too, of how a cell may
speed up its activity when it is short on fuel (in order to find new
sources), instead of slowing down, as one would expect of an inorganic
system, open or otherwise.

A cell does not achieve this ability to apply work in a goal-directed
manner by clarivoyance, it does it by means of a cognitive-like process
which I believe consists essentially of using low-energy environmental
inputs as signs (in Peircean terms, icons) of the "correct"
circumstances the cell is seeking. (BTW, there is not necessarily any
implication here of sentience in the sense of conscious awareness.)
Naturalizing my use of the word "correct" in the previous sentence is
the essence of the problem here. It is the heart of the normative and
teleological character of life which differentiates it from nonlife. I
personally think this naturalization ultimately has to be done via
quantum field theory, but be that as it may, the relative energy
autonomy from the immediate surround is the hallmark of life, and the
key factor differentiating cells from inorganic nonlinear oscillators
like hurricanes, Benard cells, etc.

I just don't see the utility of glossing over this crucial distinction.
Rather, it seems to me we need to focus on the distinction and try to
understand how the emergence of energy autonomy (with cognitively
guided, goal-directed work) out of inorganic open systems was possible.

James
Received on Wed May 22 23:04:09 2002