A model for the adaptive dynamics of the maturation age

A density-dependent time-continuous model with two groups of age is conside red both from the ecological and from the evolutionary point of view. In th e ecological context, the maturation age is dealt with as a parameter and t he existence of a non-trivial equilibrium attracting every mon-zero solutio n is proved under some hypotheses including that the birth rate is an incre asing function of the maturation age. In the evolutionary framework, condit ions for the existence and uniqueness and for the property of being converg ence-stable of the evolutionarily stable value of the maturation age are gi ven. (C) 2000 Elsevier Science B.V. All rights reserved.