This chapter focuses on evolutionary branching in niche position due to frequency-dependent competition. When the majority phenotype of a population is competing for one type of resource, selection may favor minority phenotypes that consume different types of resources, which could result in phenotypic differentiation and divergence. The idea of divergence due to competition is also the basis for the well-known concept of ecological character displacement, although here the focus is not so much on the origin of diversity arising in a single species, but rather on the evolutionary dynamics of existing diversity between different and already established species. Ecological character displacement embodies the possibility that competition between species can drive divergence in characters determining resource use. However, there are alternative evolutionary scenarios for phenotypic diversification. In the context of resource competition, one such alternative is that individuals diversify their diet by evolving a wider niche.
Periodicity and stability in a single-species model governed by impulsive differential equation
