Coevolution of competing systems: cooperation and inhibition

Abstract

Using a set of heterogeneous competing systems with intra-system cooperation and inter-system unfair competition, we show how the coevolution of the system parameters (degree of cooperation and unfair competition) depends on the external supply of resources. This kind of interactions are found in social, economic, ecological and biochemical systems; as an illustration we consider the competition between drug-selling gangs. The model consists of a set of units (individuals, machines or enzymes) grouped in a number of systems (organizations, factories or glycosomes), each one composed by a fixed number of units that can be organized in three configurations: isolated (monomers), cooperating in couples (dimers), and cooperating in groups of four (tetramers). The units working in cooperating configurations increase their ability to obtain the resources (customers, raw material or substrates). The supply of resources can be polluted by the systems through inhibitors. When an unit absorbs an inhibitor,its function is blocked during a period of time. When the blocked unit belongs to dimers or tetramers, all units in the group are also inhibited to acquire the resource. Two parameters characterize each system: the fraction of monomers and the range of the average production in which the system is allowed to produce inhibitors. By using a genetic algorithm, we observe that the evolution of the parameters of the systems maintains its long term average values for low and high supply rates, but tends to display global evolutive transitions when the supply of raw material lies between abundance and scarcity