Molecular Ethology, An Immodest Proposal for Semantic Clarification - Understanding Understanding: Essays on Cybernetics and Cognition - page 160

However, when the flow of energy between various levels of organiza-
tion is neglected, and the mechanisms of energy conversion and transfer
are ignored, difficulties arise in matching descriptive parameters of func-
tional units on one level to those of higher or lower levels. For instance, a
relation between the code of a particular nuclear RNA molecule and, say,
the pulse frequency code at the same neuron cannot be established, unless
mechanisms of energy transfer are considered. As long as the question as
to what keeps the organism going and how this is done is not asked, the
gap between functional units on different levels of organization remains
open. Can it be closed by thermodynamics?
Three different kinds of molecular mechanisms that offer themselves
readily for this purpose will be briefly discussed. All of them make use of
various forms of energy as radiation (

h ), potential energy ( V , structure),
work ( p D v ), and heat ( k D T ), and its various conversions from one form to
another.

RADIATION STRUCTURE

STRUCTURE

STRUCTURE

ENERGY

WORK

HEAT

HEAT

We remain in the terminology of finite state machines and classify the
three kinds of mechanism according to their inputs and their outputs, drop-
ping, however, for the moment all distinctions of forms of energy, except
that of potential energy (structure) as distinct from all other forms (energy).

(i) Molecular store: Energy in,
Energy out.
(ii) Molecular computer: Energy in,
Structure out.
(iii) Molecular carrier: Energy and structure in,
Energy out.

These three cases will now be briefly reviewed.

B. Molecular Store
Probably the most obvious, and hence perhaps the oldest, approach to link
macroscopic behavior, as for example, the forgetting of nonsense syllables
(Ebbinghaus, 1885), with the quantum mechanical decay of the available
large number of excited metastable states in macromolecules, assumes no
further analyzable “elementary impressions” that are associated with a mol-
ecule's meta-stable state (Von Foerster, 1948; Von Foerster, 1949). By a
nondestructive read-out they can be transferred to another molecule, and
a record of these elementary impressions may either decay or else grow,