Intracellular Dissipative Structures (IDSs) - Molecular Theory of the Living Cell - page 256

Phenomenon

Chemotaxis

(Organism)

Macroscopic Molecular Measurement

Mechanisms Mechanisms

(Macroscopic) (Microscopic)

(Holism) (Reductionism)

(External View) (Internal View)

(Global Scale) (Local Scale)

(Exophysics) (Endophysics)

(Macroperspective) (Microperspective)

(Behaviors) (Mechanisms)

Fig. 9.3 A diagrammatic representation of the postulated identity relation between chemotaxis
and its underlying mechanisms

and (2) what may be called identity as exemplified by the networks in the Chemical
Reaction Space which are deemed identical with corresponding dots on the function
plane (e.g., see apex 5 of the dotted cone whose base is labeled 4 in the Chemical
Reaction Space). In catalysis , something A allows, something else B to happen and
hence A can be said to cause B . In contrast, when two entities A and B are connected by
an identity relation, they represent two different manifestations of one and the same
entity and so no causal relations can be found betweenAandB. Thus, chemotaxis in the
Function Space is a phenotype or a phenon exhibited by a living cell under certain
environmental conditions, whereas the set of intricate molecular mechanisms
underlying chemotaxis that has so far been characterized on the levels of chemical
reactions (Chemical Reaction Space), protein dynamics (Protein Space), gene expres-
sion (RNA Space), and genetic mutations (Gene Space) represent the inner workings
of the cell that performs chemotaxis. We may represent the identity relation between
chemotaxis and its molecular mechanisms graphically as shown in Fig. 9.3 Because it
is believed that the identity relation can be thought of as belonging to the relation type
known as supplementarity , symbolized as in Sect. 2.3.1 , this symbol is employed here
to represent the identity relation.
The key point of Fig. 9.3 is that the phenomenon of chemotaxis can be observed
(or measured) in two contrasting ways - from outsid e of the organism on a
macroscopic or mesoscopic scale and from inside the organism at the microscopic
one (e.g., by artificially separating the working components of the organism and
studying them in isolation at the molecular level). The results of the measurements
so obtained are very different, giving rise to various dichotomous pairs descriptive
of their differences, including holism versus reductionism , external (or exo) versus
internal (or endo) views, global versus local views, exophysics versus endophysics ,
macroviews versus microviews , and behaviors versus mechanisms , etc. The identity
relation symbolized as an inverted T in Fig. 9.3 (as compared to the complemen-
tarity relation symbolized by ^ in Eq. 2.32 ) may be viewed as an example of the
supplementarity relation discussed by Bohr (1958) and in Sect. 2.3.1 in the sense