Evolutionary Dynamics Analysis of GAs for Problems with Neutrality by the Nei's Standard Genetic Distance
Yoshiaki KATADA, Kazuhiro OHKURA
Neutrality, which is caused by highly redundant mappings from genotype to phenotype or from phenotype to fitness, has been recognized as an important factor for artificial genetic search. However, this research field has still been trying to overcome the difficulties of analyzing evolutionary dynamics at the level of phenotype space or fitness space for about ten years. On the other hand, considering that population genetics explains the change of gene frequency in a population, that is, dynamics at the level of genotype space, we expect that various techniques developed in population genetics might be useful for analyzing dynamics of artificial evolution. In this paper, we apply the Nei's standard genetic distance to artificial evolution. Several computer simulations are systematically conducted by applying a standard genetic algorithm to a tunably neutral NK landscape in order to clarify the characteristics of the Nei's standard genetic distance in genetic algorithms. The results prove several consistencies with the (nearly) neutral theory of molecular evolution.