We provide a conceptual framework for studies of the developmental and evolutionary ecology of marine invertebrate larvae and illustrate how contributions to this volume demonstrate both past achievements and the future fecundity of this research program. Our conceptual framework is anchored in the idea of model life histories, which is a category of investigation similar to but distinct from model organisms or model clades. Marine invertebrate larvae constitute a coherent, structured research program as model life histories that represent developmental, ecological, and evolutionary processes in different ways. They facilitate interdisciplinary investigation that integrates different approaches to diverse research questions about developmental mechanisms, evolutionary history, and adaptation, as well as providing a window on alterations of the marine environment due to anthropogenic climate change. Success in studies of model life histories provides a strong case for sustained professional, institutional, and financial support to carry these endeavors forward.