Digital-analogical consensus

Digital-analogical consensus can be defined as the mediatory action of codes which are formed at different hierarchical levels out of an indefinite number of dyadic causal relations, specific “lock and key” interactions, that by their simultaneous occurrence give rise to emergent and “de-emergent” specificities and triadic relations.

This process can be described as the formation of an interpretant by the simultaneous (synchronic) occurrence of a combination of factors, determinants or circumstances.

In other words, the continuous code-dual process that through an indefinite set of digital messages in simultaneous occurrence forms an analogical message that is interpreted (sensed/formed) as the context by the emergent interpretant.

In a reducible perspective, this could be viewed as the emergence of new analogical signs (properties, contexts, pieces of information) by the aggregation of digital signs.

By the same token, the analogical mode (the bulk of information) influences the circulation of digital information (downward causation). These influences from above can contribute to determine new configurations at lower levels.

But the emerging analogical compound effect may also constitute a "quasi-digital" piece of information to a higher level of aggregation ("to be or not to be"). In this way the new analogical sign can be a digital contribution to a still larger or more complex analogical sign (Bruni, 2002).

We encounter emergent processes in which new levels and kinds of signification in biological processes appear. And these new levels of signification are not always specified by the precedent lower hierarchy process. As with many emergent

properties, one can not exclude downward causation.

The process has a hierarchical and emergent nature and it implies levels of integration in which a myriad of dyadic causal relations at a given level contribute to the emergence of the interpretant in a process mediated by triadic causal relations.

Here, hierarchical levels do not imply a limited number of levels. It refers rather to the emergence of interpretants in a continuous process.

Through this constant hierarchical digital-analogical conversion, “information” is

“conveyed” from lower to higher systems and vice versa, information and contexts emerge and semiotic processes have a causal link to higher, parallel or lower levels in the hierarchy.

An emerging "state" constitutes a difference that can be sensed by some system with interpretative capacity. Every effective difference denotes a demarcation, a line of classification, and all classification is hierarchic. In other words, differences are themselves to be differentiated and classified (Bateson, 1972: 457). But also complex aggregates of differences are to be differentiated and classified. That is why semiotic description is always hierarchic.

“... there is that hierarchy of differences which biologists call ‘levels.’ I mean such differences as that between a cell and a tissue, between tissue and organ, organ and organism and society.

These are the hierarchies of units or Gestalten, in which each subunit is a part of the unit of the next larger scope. And always in biology, this difference or relationship ... is such that certain differences in that part have informational effect upon the larger unit, and vice versa” (Bateson, 1972: 458).

In 1950 geneticist Hans Kalmus claimed that since the action of a particular gene was sometimes felt in a distant cell, genes acted more like a “broadcasting system”

than “wired telecommunication” (Sarkar, 1999: 203). DNA digitally encodes an analog, i.e.: a protein. This analog by binding or not binding a correspondent protein (or nucleic acid), that is, by being or not being (there), may also become a digital message. But the simultaneous expression of a set of genes may constitute itself an analogical message (with its respective context). This type of message is not itself specified by digital DNA. In this sense Kalmus’ “broadcasting system” “irradiates” an analogical multidimensional wave rather than the linear digital impulses of wired telecommunication.

Just as in human language larger narratives represent a kind of analogical information that emerges from the underlying digital code (natural language), larger aggregates of digital information become analogical when its complex interactive dynamics become explicit. This dynamic up-and-down causality mediated by signs is an ontogenetic historical continuum that oscillates within the boundaries of the code-dual nature of organisms and ecosystems.

In chapter 3 I will elaborate some detailed examples of this principle in relation to signal transduction and metabolic regulation. For the moment let me furnish some short illustrative examples from different hierarchical levels hoping to facilitate its understanding:

1) The transformation pathway in bacteria (as well as conjugation and

transduction) works through a set of emergent "lock and key" binding mechanisms (which may be more or less specific). That means that "competence" is the

aggregation of different specificities.

2) The relative composition of a blend of volatiles emitted by a particular plant infested by a specific herbivore (Takabayashi and Dicke, 1996; Shiojiri et. al., 2001) is the real message and not the compounds themselves, i.e.: the blend functions as an analogical message formed from a complex mix of digital information, the presence or absence of a certain threshold concentration of each compound. However each

compound’s concentration is in turn an analogue that is formed out of the digital presence or absence of each molecule, which in turn are tridimensional analogues, an so on.

3) The complex specificity of the host-symbiont relation is determined by an aggregate set of specificity determinants which in turn are conformed by lower level specificities. In section 2.6 I give a more detailed treatment of this example by

describing the Vibrio fischeri-Euprymna scolopes symbiotic relationship as a semiotic network built from emergent specificities that range from the workings of the Lux operon in the genetic organisation of the bacterium, to the different levels of specificity determinants in the symbiotic relation, up to the emergence of the particular context that gives the squid the chance to avoid being predated at higher trophic levels (with the help of the bacterium).

4) The fact that in some cases the recognition of a given avirulence factor may require not one but several host genes, which in turn may need several other biotic or abiotic (contextual) cues, offers the possibility of a creative response to a very specific challenge, i.e.: the formation of a very sophisticated habit, the emergence of a

resistance response. This sophisticated habit based on the interpretation of a complex cocktail of dyadic relations could be compared to our capability of producing new thoughts by “synthesising” a whole new idea from subordinate thoughts.

5) The configurational changes experimented by the ribosome (an analog) during protein synthesis result from specific combinations of proteins bound to it in complex interactions. Here each protein acts as an individual digital message (by binding or not binding), but at a lower level each protein is an analog that results from complex interactions of digital messages.

6) In neurons, inositol triphosphate receptors (InsP3Rs) are sensitive to both inositol triphosphate and calcium ions. They are thought to act as “coincidence detectors” to correlate the activity of pre- and postsynaptic inputs, which is central to memory formation (Berridge et. al., 2000: 13). This is hardly just some idiosyncratic detail in a particular “mechanism”, this is a general rule in biological processes.

Almost all genetic circuits obey to suites of signals and regulators that have to act simultaneously and which result in the emergence of a complex phenotype.

7) In the phenomenon of “synaptic summation”, when two neurons, A and B, have synaptic connection to a third neuron, C, the firing of neither neuron by itself is sufficient to fire C; but when both, A and B, fire simultaneously (or nearly so), their

combined action will cause C to fire. From the physical point of view, this combining of events to surmount a threshold is called a “summation”. But from the semiotic point of view this synergy would not be a summation. The system operates to create differences. There are two differentiated classes of firing by A: those firings which are accompanied by B and those which are not. Similarly there are two classes of firings by B. The so-called “summation”, when both fire, is not an additive process from this point of view. It is the formation of a logical product - a process of fractionation rather than summation (Bateson, 1972: 457).

We can consider the interplay of code-duality (Hoffmeyer and Emmeche, 1991) - the constant digital-analogical-digital translation, from the genome space to the global phenotype, and vice versa - as a sort of homeostatic system of mutual determination.

What connects all this is the process of semiosis: the indeterminate chain of triadic relations that “make sense” out of the material-energetic exchanges present in the bio-mass, and which give rise to the distinctive characteristics of living dissipative structures and their goal-oriented behaviour.

It should not be hard to acknowledge the context-dependent nature of any kind of information. A context can be a larger aggregate of information, a set of simultaneous occurrences that conform a sign that is received in its complexity by the interpreting system. The context could be characterised in terms of digital-analogical consensus, but evidently it is not fully quantifiable.

The important thing is that at a certain point, at a certain time and place, a quality is formed and/or sensed, and that perception generates causality or “agency”, that is, it presupposes a next step. For this reason, when dealing with semiotic processes

qualities become important. So in order to characterise a semiotic network it is necessary to characterise the context, which by being an analogical complex combination of factors - and by having an effect upon different logical levels of causality in the hierarchical process under study - has a qualitative nature hard to quantify. This is the level at which we have to rely on monitoring patterns to aid our characterisation of the context. This characterisation can be achieved not so much by pinpointing every quantitative detail of the picture but by relying on the cyclic

appearance of patterns, in our effort to get, as much as possible, a less static picture of the context in evolution.

The next problem would be how to explore and how to chose which patterns can be useful in the characterisation of the context of the semiotic network under study.

This is related to the problem of how to take the best advantage of the enormous quantity of empirical data that is being produced, in other words, how to organise the data into an integrating description that relies on patterns.

Digital-analogical consensus provides complex possibilities for fine-tuning responses to variable contexts in an incredible creative combinatorial manner.

Visualising biosemiotic processes in this way can be useful to organise hierarchically the suits of factors that determine or influence emergent properties in a given causal network.

In summary, one has a configuration of many digital instances, presences, combinations of locks and keys, threshold concentrations, that create an analogical state, a compound effect, a quality which (triadically) finds its relevance, its

significance, at an emergent level. Signal transduction networks are an instance of this kind of relations. Combinations of many signal transduction networks compound an analogical message that (homeostatically) regulates a higher order process, property, state or phenotype.