If all origins of life or of any new grade, level, or major transition as such begin with “competitive development”—with juveniles rather than adults, and multiple individuals rather than a single one—then the evolution of progeneration and of replication always requires an explanation. This article proposes that principles of evolutionary ecology such as density-dependence can be used to explain three kinds of developmental repetitions, viz., sequences of inductive and niche-constructing interactions between the ecological environment and population members, which take place (...) in such a way that the sequence is repeated: individual or somatic repetitions, discussed in Section 1, demographic or progenerative repetitions , discussed in Section 2, and replicative repetitions , discussed in Section 3. This results in a statement of the evolutionary process that includes rather than excludes development and ecology, but one which requires some additions to Van Valen’s aphorism that evolution is the control of development by ecology. (shrink)

Traditional model systems such as fly, mouse, and chick have formed the foundation of the EvoDevo research program. These animal systems have provided a wealth of information on the patterns and mechanisms of developmental change over large phylogenetic scales. However, the almost exclusive focus on individual embryos as model organisms has also limited the field’s ability to address the central roles that natural selection and life history adaptation play in the evolution of developmental systems. Likewise, focus on this small set (...) of “unitary” model organisms may also constrain the explanatory reach and theoretical robustness of EvoDevo if we consider that many core developmental processes like homeostatic regulation, ontogenetic differentiation, and norms of reaction are also manifest at other levels of biological organization, such as colonial organisms. The study of social insect systems can help bridge these considerable gaps in EvoDevo’s current approach. Because social insect colonies span the fine line between simple associations of “unitary” organisms and full-fledged “superorganisms,” these systems help elucidate what kinds of processes fundamentally characterize developmental systems and their evolution. What is more, the traits of social insect colonies show high degrees of population-level variability that can be linked directly to selective factors in the environment, making them ideal systems in which to more fully integrate EcoEvoDevo approaches. (shrink)