OLM 8.2. Fitness in age structured populations
It is of central importance that any kind of reproductive unit has a well-defined fitness, i.e. asymptotic growth rate, at fixed values of the regulating and modifying variables. We introduced briefly a description of age-structured populations in TBox 8.2 (p.154). For this case fitness is defined by the Euler-Lotka equation (Eq. (8.15), p.155), which we derive here.