Population Structures C 6 . 2 Speciation methods

In nature, a species is defined as a collection of phenotypically similar individuals. Many biologists believe that individuals in a sexually reproductive species can be created and maintained by allowing restrictive mating only among individuals from the same species. The connection between the formation of multiple species in nature and in search and optimization problems lies in solving multimodal problems, where the objective is not only to find one optimal solution, but to find a number of optimal solutions. In those problems, each optimal solution may be assumed to constitute a species. Since evolutionary algorithms work with a population of solutions, the concept of natural speciation techniques can be implemented to allow formation of multiple subpopulations, each focusing its search for one optimal solution. This way, multiple optimal solutions can be discovered simultaneously. In this section, a number of speciation techniques are discussed.