Determinants of maturation in animals.

Maturation is a critical transition in the life cycle. Recent models have used retrospective analyses of patterns of variation in age and size at maturity in an attempt to understand the mechanisms responsible for generating phenotypic variation in maturation. Empirical work has revealed greater complexity in the biology of maturation than has been incorporated in current models, and has cast doubt on some of the assumptions and conclusions of the models. Recent insights from experimental work, coupled with theoretical advances for the analysis of growth, size and other complex characters, have great potential to elucidate evolution of maturation and how adaptive maturation phenotypes are achieved by real organisms.