Self-Organization and Evolutionin a Simulated Cross Catalyzed Network

Motivated by an alternative to the concept of a prebiotic soup inthe form of interacting crystal growth close to hot vents, we investigatea model system in which the growth rate of a particular entity is modified (enhanced or reduced) by other entities present, thus forming aweb of cross catalysis. Initially random interactions are imposed, butthe entities compete for a common source, and some entities may thusvanish in the competition. New entities, or mutations (error copies),with randomly selected interactions to the web are then introduced,and the concentrations of the entities are followed as solutions to stiffordinary differential equations. Entities with positive growth maycreate new related entities with slightly randomly modified interactions to the web. Extinctions, wild-type survival and replacement,and self-organization to sustain periodic external variations, are studied. It is shown that even systems with mostly cross-inhibition and noinitial autocatalysis may eventually create highly stable self-organizedsystems. We find that an already established cross catalyzed systemoften wins over a selfreplicating invader (or mutant).