A major goal of biological and ecological sciences is to understand natural systems well enough to predict how species and populations will respond to a rapidly changing world (i.e., climate change, habitat loss, etc.). A population under any conditions will grow, shrink, or disappear altogether depending on how efficiently individuals consume resources (food), utilize that food metabolically, and eventually reproduce. However, making accurate predictions based on these metabolic processes is complicated by the realities that each species has different resource requirements and that no two individuals within a species are exactly alike. Rather, individuals vary and this variation, both within and across species, is central to many ecological and evolutionary processes. Developing the ability to predict responses of biological systems to a changing world therefore requires a mechanistic understanding of variation. The goal of this project is to improve this mechanistic understanding by examining variation within a metabolic context across a range of species that have a spectrum of commonly-seen resource requirements. Further, the work capitalizes on a unique biological characteristic of this group of species that allows control and manipulation of individual reproduction, facilitating experimental study of the mechanistic links between variation in individual consumption, metabolism, and reproduction. The foundation this research is a combination of field measurements and laboratory experiments using both well-established and newly-developed techniques to quantify these links. The result will be a quantitative framework to predict how individuals will respond reproductively to changes in resource use. Because of the close link between individual reproduction and population dynamics, this research will contribute substantially to predictions in population dynamics under realistic conditions where individuals use more than a single resource, and improve the prediction of responses to current and future ecological changes.
Broader Impacts: The research will make broad contributions to society in three ways. (1) The development of K-12 lesson plans to enhance science education, contributing to the broader goal of enhancing early STEM education in the United States. This aspect of the project brings together local grade school teachers, undergraduate students in elementary education from the University of South Carolina (USC), and experts from the USC Center for Science Education to develop a series of lesson plans based on the proposed scientific investigations. (2) Improve commonly used chemical tool (stable isotopes) used in assessing food web links in ecological systems. (3) Improve understanding of species of management concern. Several of the study species are of management concern because they are either problematic invaders in many areas globally, are currently increasing in abundance as a result of reduced consumer pressure because of overfishing, or are dominant yet understudied consumers in their respective habitats. This study will provide important information on the impacts of these species, as well as on their reproductive potential.
