A Common Framework for the Regulation of Growth and Size: Stepping Away from the Trees to See the Forest

Life histories, the demographic patterns of the life cycle that make up growth, maturity, reproduction, and survival, are the basis of our understanding of how organisms cope with their environments and how populations and species evolve. This chapter aims to use the Manduca model to build a more general framework for the regulation of body size that is applicable across taxa. Overall, it aims to show that such a framework is possible and that it can generate mechanistic insight into the ecology, evolution and constraints on major life history traits in a broad range of taxa. That is, the framework allows us to step away from system-specific detail (the "trees") to understand general life history phenomena (the "forest"). The general framework for the regulation of growth and size has four components, which, in ontogenetic order, are: the decision point; the terminal growth period (TGP); the cessation of growth; growth rate.