Symposium Overview

Complex life histories are an important aspect of the biology of organisms, and occur in almost all animal phyla and plant divisions. The study of complex life-histories has been, and continues to be, an important focal area of study that allows us to integrate across disciplines including ecology, evolution, development, physiology, and behavior. Among animals, the greatest diversity of life-histories is found in marine invertebrates. Virtually all animal phyla originated in marine systems, and current evidence suggests that the ancestral condition for most animal phyla is a complex life-history. These complex life-histories result in early life stages that are physiologically, morphologically, and ecologically different from later stages, and there are intriguing phylogenetic patterns of complex life-histories among species of marine invertebrates—including convergence of adult forms with different larval types, and convergence of larval forms with different adults.

To date the major questions that have been addressed with marine animals with complex life-histories include:
• Why did complex life-histories evolve, why and when might they be retained, lost, or regained?
• What are the developmental processes that allow for complex life-histories, and how labile are those processes?
• What ecological forces maintain or drive shifts in life histories?
• What are the ecological and evolutionary causes and consequences of complex life-histories?

We have assembled leaders in the studies of complex life-histories of marine invertebrates for a symposium that will be held at the annual meeting of the Society for Integrative and Comparative Biology in San Diego, California in January of 2005. This symposium will combine forward thinking and syntheses of ideas for guiding future studies of complex life-histories of marine animals.

Goals of the Symposium

There are three major motivations for this symposium. The first is to synthesize the recent advances in our understanding of complex life-histories in marine invertebrates. The most recent reviews of a similar topic were the focus of a book edited by Dr. McEdward published 1995 entitled “Ecology of Marine Invertebrate Larvae”, and a collection of papers published in Oceanologica Acta in 1996 on the theme of biotic and abiotic interactions regulating life cycles of marine invertebrates. Since these publications there have been several major advances in our understanding of complex life-histories in marine invertebrates, including the ecological forces that drive evolutionary shifts in life histories, the developmental mechanisms that allow for these shifts, the ecological and evolutionary roles of dispersal via larvae, and the linking of larval condition with later life-history stages. The second motivation is to provide a forum to facilitate interactions between students and leaders in the field to promote graduate student education. The third is to honor Dr. McEdward and his scientific contributions.

To accomplish these three objectives, we are organizing a symposium, an associated paper session, and a social. The symposium is composed of presentations by leaders in the field who will synthesize the recent advances in their respective fields, and provide future directions and challenges, especially those that are a result of Dr. McEdward’s legacy. The contributed talks will be presented by graduate students and recent graduates, highlighting the work of newcomers to the field. We hope this combination of a symposium with an associated session leads to more interaction between both junior and senior investigators and increases impact of the symposium. In addition, we hope that the social event also facilitates one-on-one interactions between junior and senior scientists, and leads to future collaborations.