Estimating the Degree of Neutrality and Ruggedness of Fitness Landscapes

Abstract

In recent years, not only ruggedness but also neutrality has been recognized as an important feature of a fitness landscape for genetic search. As it has been reported that the evolutionary dynamics on a fitness landscape with neutrality is clearly different from the canonical explanations, ruggedness alone might be inadequate describing it. Another measure, i.e., neutrality is required. This study discusses the use of standard genetic distance, which originates from population genetics, for measuring neutrality of fitness landscapes. Firstly, several computer simulations are conducted with a test landscape with neutrality as well as ruggedness in order to clarify the characteristics of standard genetic distance on it. Second, computer simulations are conducted with an evolutionary robotics problem which would be expected to include neutrality in its landscape in order to investigate the validity of the proposed approach on a real-world problem. The results suggest that genetic distance is a reliable method for estimating the degree of neutrality of realworld problems.