Branching Point

A branching point in adaptive dynamics is an evolutionary singularity that is convergence stable — nearby traits evolve toward it — but not evolutionarily stable. At a branching point, the population experiences disruptive selection: the resident trait is optimal against itself, but mutants on either side of the resident have higher fitness when rare. This creates a selective pressure toward polymorphism, which can lead to the evolutionary splitting of a single lineage into two distinct strategies. Branching points provide a theoretical mechanism for speciation and phenotypic diversification without geographic isolation. See also: Adaptive dynamics, Evolutionary Singularity, Speciation