Measures of Work in Artificial Life

Definitions of autonomous agents—simple living systems— have often included the thermodynamic idea that agents need to do work to construct constraints and to maintain these constraints. We show that an ant-pheromone system is sufficiently rich to allow an explanation of its behavior in terms of thermodynamic properties, particularly the work done by the system on itself to build structure. This work is done by an inward pressure whose origin is the antpheromone system itself. The degree of structure formed by the system can be traced back to the behavioral rules of each of the ants—the more relevant information each ant is given in its behavioral repertoire, the more work is done by the system in compressing itself, and the tighter and more constrained is the final structure. The language introduced in this paper can serve as a framework for quantifying the propensity of a system to do work, self-organize and coalesce into life.