Code Regulation in Open Ended Evolution

We explore a homeostatic approach to program execution in computer systems: the “concentration” of computation services is regulated according to their fitness. The goal is to obtain a self-healing effect so that the system can resist harmful mutations that could happen during on-line evolution. We present a model in which alternative program variants are stored in a repository representing the organism’s “genotype”. Positive feedback signals allow code in the repository to be expressed (in analogy to gene expression in biology), meaning that it is injected into a reaction vessel (execution environment) where it is executed and evaluated. Since execution is equivalent to a chemical reaction, the program is consumed in the process, therefore needs more feedback in order to be re-expressed. This leads to services that constantly regulate themselves to a stable condition given by the fitness feedback received from the users or the environment. We present initial experiments using this model, implemented using a chemical computing language.