Dissertation Research: Feedback between ecological interactions and evolutionary processes in a trophic cascade

University Of California-Davis, Davis CA

Investigators

Abstract

Trophic cascades, ecological interactions in which predators suppress herbivores and so indirectly benefit plants, are among the most widely studied multi-species interactions. This research will examine how trophic cascades affect natural selection and evolution of the common monkey flower plant (Mimulus guttatus). The presence of both arthropod herbivores and predatory spiders will be manipulated in the field and responses of several genetically-variable plant traits will be measured to assess changes in selection pressures associated with those treatments. Changes in plant traits also have the potential to influence the strength of trophic cascades. The importance of this feedback mechanism will be measured directly, by growing offspring of plants from each treatment in every treatment the following season, and indirectly, by using artificial selection to manipulate plant traits and then placing selected lines into each treatment. Understanding complex multi-species interactions in ecological communities remains a key challenge for ecology. The intellectual merit of this research is that it will add to our understanding of the interplay between genetic variation, natural selection, and multi-species interactions in complex ecological communities. The broader impacts of the research include student training, and that it will generate important insights for managing both species diversity and genetic diversity in natural and agricultural systems. Understanding potential feedbacks between the variable interactions among different species and the genetic variation present within species will also help in predicting how ecological communities will change as species diversity and genetic diversity are altered by humans.