abstract:

This paper investigates the dynamics of evolutionary algorithms (EAs) without fitness based selection (constant fitness). Such algorithms exhibit a behavior similar to the MISR effect (mutation-induced speciation by recombination) which has been found in the analysis of   evolution strategies. It will be shown that this behavior can be observed in a variety of EAs, not only in unrestricted search spaces, but also in binary GAs. The quantification of this effect is done by introducing the expected population variance $\sigma_P^2$. The evolution of $\sigma_P^2$ over the time g is analytically calculated for both unrestricted and binary search spaces. The theoretical predictions are compared with experiments. The genetic drift phenomenon and the diffusion effect are derived from the general $\sigma_P^2$ formulae, and it will be shown that MISR is a finite population size sampling effect which cannot be observed in infinite populations.
 

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