The Use of Neutral Genotype-Phenotype Mappings for Improved Evolutionary Search

In natural systems, the organism or phenotype is the result of a complex developmental process that is played out as the genetic information is interpreted. This is in stark contrast to many artificial evolutionary systems in which the phenotype is represented directly in the genetic information and there is no such development. As well as overcoming the obvious practical impossibility of directly specifying an organism in the genotype, the developmental process may yield other desirable properties. One such property is neutrality in which many genotypes develop into the same phenotype. This paper examines the effect of neutral genotype-phenotype mappings on artificial evolutionary systems through examination of an abstract redundant mapping based on a random Boolean network (RBN). It then goes on to examine the genotype-phenotype mapping within a planning tool that evolves instructions for growing telecommunications networks. It is demonstrated how the right kind of redundancy has the potential of significantly aiding the evolvability of a system.