The Evolutionary Ecology of Complex Life Investment Strategies

Abstract.  Environments that vary over spatial and temporal scales impose tremendous selective pressures on organisms. These pressures require organisms to adopt complex investment strategies that incorporate the production of multiple phenotypes and occupation of separate ecological niches. One example of such a strategy is a complex life cycle whereby genotypes reproduce by sequentially progressing through different phenotypes. Parasites and algae often adopt these strategies, progressing through three or more distinct phenotypes. Another example of a complex life investment strategy is a life history trait that varies over the life-span of an organism. Steelhead salmon (Onchyrynchus mykiss) exemplify such complex life-history strategies, as they spawn in freshwater habitats, and transition to the ocean to forage and grow; these freshwater/oceanic transitions may occur multiple times throughout a single lifespan. While both life cycles and life history traits are complex investment strategies, they are often studied in different ways in different systems. Life cycles tend to be examined from an evolutionary perspective in the context of microorganismal systems while life history traits are often studied in much larger organisms from an ecological perspective. Yet, there is an increasing awareness that these two perspectives can be combined and the resulting synergy improves understanding (consider the increasing usage of the term “eco-evolutionary"). This workshop will bring together researchers interested in either complex life cycles or life history traits to identify common themes and applicable approaches.