Trait Substitution Sequence

A trait substitution sequence is the step-by-step process by which a rare mutant trait invades a resident population and replaces it, leading to a monomorphic population with the new trait value. In adaptive dynamics, trait substitution sequences are the elementary events that compose the evolutionary trajectory: each step is a rare mutation, a period of invasion while rare, and a fixation or extinction. The canonical equation of adaptive dynamics is derived as the limit of many small trait substitution sequences occurring in succession. When the assumption of rare, small mutations breaks down, the population may become polymorphic and the trait substitution sequence framework ceases to apply. See also: Evolutionary Dynamics, Adaptive dynamics