Thomas A. Sebeok: "The Sign Science and the Life Science"


The metabolic code constitutes still another fascinating set of endosemiotic properties, because, as Tomkins (1975) showed in his brilliant article completed just prior to his death, complex regulation is characterized by two entities not operating in simple mechanisms: these are metabolic symbols and their domains, where the former "refers to a specific intracellular effector molecule which accumulates when a cell is exposed to a particular environment" (ibid.:761). For example, cyclic adenosine monophosphate (cAMP) acts, in most micro-organisms, as a symbol for carbon-source starvation, or ppGpp acts as a symbol for nitrogen or amino acid deficiency. Without going into details, the conspicuous point to note here is that, while a simple regulatory mode, that is, a direct chemical relationship between regulatory molecules and their effects, is a clear instance of Peirce's "secondness, or dependence," the complex mode is an instance of "thirdness, or mediation" (3-422). This insight was foreshadowed by Peirce himself in his observation that a "rhema is somewhat closely analogous to a chemical atom" (3-421). Tomkins's reasoning (1975:761) is highly semiotized: "Metabolic symbols need bear no structural relationship to the molecules which promote their accumulation," and, since a particular environmental (or contextual) condition is correlated with a corresponding intracellular symbol, the imputed "relationship between the extra- and intracellular events may be considered as a 'metabolic code' in which a specific symbol represents a unique state of environment."

The endocrine and the nervous systems, as noted above, are intimately fastened together via signs. As for the neural code itself, semiosis is what neurobiology is all about. "The modes of communication include membrane conductances, patterns of neural spikes and graded potentials, electric coupling between cells, electrical and chemical transmission at synapses, secretion, and modification of neural function" (Prosser 1985: 118). The basic principle for understanding most sign use by neurons comes down to the selective permeability of their plasma membrane to ions (charged atoms), which seem to penetrate through specific pores, or channels, in the membrane. Another newly labeled interfacial field of research is "neurocommunications," which aims to portray in a current jargon the (human) mind, or "software level," and brain, or "hardware level," as a pair of semiotic coupled engines, namely, computational devices for verbal-nonverbal sign processing.

Beyond endosemiotics, the literature of biosemiotics distinguishes among phyto-, cyto-, and zoosemiotics, the latter comprising a specially marked branch, anthroposemiotics, to reflect its predominantly glottocentric emphasis, amounting at times to an obsession. These distinctions correspond exactly to the standard classification of eukaryotic multicellular organisms into the plant, fungus, and animal super-kingdoms, the last including the animal loquens. The minor tradition I cited above concentrates on anthroposemiotics to the exclusion of all the other divisions; it excludes, that is, almost all of the rest of nature.

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AS/SA Nº 6/7, Article 5 : Page 5 / 8

© 1999, AS/SA

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