Eco-Evo-Devo

Abstract

Because environmental conditions influence gene expression as well as metabolic processes, an organism's development is not scripted in its DNA but takes shape through the interaction of genotype and environment. This expanded understanding calls for several significant lines of investigation. Ecological developmental biology ("eco-devo") extends the study of developmental mechanisms and their phenotypic outcomes to include environmental context dependency. The starting point for an ecological development approach is to characterize the environmental response patterns or norms of reaction of genotypes in taxa of interest to ecological factors relevant to their natural settings. Another major line of eco-devo research is to determine precisely how developmental pathways incorporate environmental inputs so as to generate these context-dependent phenotypes. Answers to this question of mechanism include a fascinating array of regulatory systems, from well-studied hormonal transduction pathways to environmentally induced molecular epigenetic changes. More fundamentally, an eco-devo approach points to two further research questions of broad resonance for evolutionary biology: How do such environmentally responsive developmental systems evolve? And how does this developmental flexibility itself affect the processes of adaptive evolution and diversification? This chapter provides a brief overview of the central issues that comprise this "eco-evo-devo" territory, ending with a section on practical considerations for the design of empirical studies.