How and why organisms allocate resources to different functions such as growth, maintenance and reproduction is a fundamental aspect of their biology. Understanding patterns of allocation addresses fundamental questions about the evolution of a wide variety of plants and animals. The way that organisms mate with each other (their mating system) is often related to the way they allocate resources. For example, in species where a single male mates with multiple females, males may express particular traits that increase their chance of successfully obtaining a mate. In some species, such as freshwater snails, individuals are male and female at the same time, and therefore have the option to self-fertilize if no mates are available. Previous research has resulted in a predictive theory that relates the way organisms mate (with/without a partner) to how they grow and when they become mature. In this three-year interdisciplinary research project, this theory with be extended and tested using a combination of mathematical modeling and experimental tests using snails. The project will also promote cross-disciplinary education of diverse undergraduate students and high school teachers.
There is a close relationship between the expression and evolution of the mating system and other life-history traits. Individuals of many species may be able to alter their allocation of resources based on the availability of mating partners, and the pattern of mating itself can affect when individuals initiate reproduction and how much they allocate to gamete production and mate attraction. A particular example of this is revealed by simultaneous hermaphrodites that can reproduce by self-fertilization or outcrossing: Individuals that prefer to outcross may delay the initiation of reproduction if mates are not available. In this project, the researchers will develop a series of mathematical models to explore the role that a variety of realistic yet complicated environmental factors play in determining life-history expression and evolution. They will explore the consequences of (1) demographic stochasticity, (2) inducible defenses, and (3) spatial structure on the expression and evolution of optimal life-history strategies. Each model will be paired with an empirical test using a well-developed experimental system (freshwater snails) that will allow a test of the model results. Collectively, the project will improve the predictive and explanatory power of how individual life-history strategies and the mating system interact.
