Hitchhikers Get Around

Previous studies have shown that hitchhiking in standard GAs can cause premature convergence. In this study we show that hitchhiking also occurs in adaptive operators, specifically, selective crossover an adaptive recombination operator. We compare selective crossover with uniform crossover (a highly disruptive operator) and show that although selective crossover favours hitchhikers more than uniform crossover it does not show worse performance. The constant adaptive behaviour and evolvability allows selective crossover to suppress hitchhiking and thereby yield better performance. Further experiments show that hitchhiking cannot be eliminated completely in selective crossover but can be reduced and further increase performance.