Emergence of Different Mating Strategies in Artificial Embodied Evolution

In nature, discrete alternative mating strategies have been observed in many different species. In this paper, we investigate the emergence of different mating strategies in a small colony of simulated robots, using our previously proposed framework for performing embodied evolution with a limited number of robots. The virtual agents can reproduce offspring by mating, i.e., an exchange of genotypes with another robot. In the experiments, we observed two individual mating strategies: 1) Roamer strategy, where the agents never wait for potential mating partners; and 2) Stayer strategy, where the agents wait for potential mating partners depending on their internal energy level, the distance to the mating partner's tail-LED, and the distance to the closest battery. The most interesting finding was that in some simulations the evolution produced a mixture of mating strategies within the population, typically with a narrow roamer subpopulation and a broader stayer subpopulation with distinct differences in genotype, phenotype, behavior, and performance between the subpopulations.