Information and the Nature of Reality : From Physics to Metaphysics (9781139753623) by Davies Paul (EDT); Gregersen Niels Henrik (EDT) & Niels Henrik Gregersen

Author:Davies, Paul (EDT); Gregersen, Niels Henrik (EDT) & Niels Henrik Gregersen
Language: eng
Format: epub
Publisher: Cambridge Univ Pr
Published: 2010-03-14T16:00:00+00:00

Terence Deacon has suggested an even more simple system as a candidate for the prebiotic emergence of life and agency, a system that he calls the “autocell” (Deacon and Sherman, 2008). Autocells are self-assembling molecular structures that derive their individuality from a synergistic relationship between two kinds of self-organizing processes that reciprocally depend upon one another’s persistence. Such autocells could have been an important stepping stone in the process leading from the non-living to the living. However, as Deacon and Sherman themselves point out, autocells are not yet full-blown living systems. They lack several features that are generally considered criteria for being alive, such as the possession of the replicative molecules of RNA or DNA, and differential survival through replications. Furthermore, autocells will not meet the set of criteria put forward by Kauffman and Clayton. The autocell model, however, does demonstrate a possible unbroken continuity from thermodynamics to evolvability.

The difficult problem to solve in any theory of the origin of agency and life is how to unify two normally quite separate kinds of dynamics: a dynamics of chemical interaction patterns and a dynamics of signification or semiosis. This immediately places this question in the contextual situation of the environment. The Kauffman–Clayton criteria clearly do so, but they also presuppose a far more complex beginning than Deacon’s autocell model. It remains to be seen if, or how, these two approaches might be reconciled.

Biosemiotics, of course, immediately reminds us that “to ask for the origin of life is to ask for the origin of the environment” (Hoffmeyer, 1998). Living organisms are inscribed in their environments much like patterns woven into a carpet – the two cannot get apart. From a semiotic point of view, the decisive step in the process that led to the origin of life was the appearance in the world of a new kind of asymmetry, an asymmetry between inside and outside. The formation of a closed membrane around an autocatalytically closed system of components (Kauffman, 1993) might have been an initial step. Such a membrane would have created what is probably the most essential and unique characteristic of life: the never-ending interest of the insides into their outsides or, in other words, cellular aboutness. I have suggested that this “interest” should be understood as a property that ultimately was derived from the primordial membrane itself. A closed membrane sheet necessarily has two distinct kinds of exterior: the inside exterior and the outside exterior. For agency to appear, such membranes must have managed not only to canalize a selective flow of chemicals across themselves, but also to subsume their interior system of components to help them resist the flow of perturbations from the outside exterior. Or, in other words, for the membranes to persist, they would have to function as interfaces connecting their inside worlds to the outside world. At some point in prebiotic development, a self-referential digital description (in RNA or DNA) of constitutive “cell” components was established. For a prebiotic system to become a true living system,

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