Dissertation Research: Climate Change, Range Limits and Adaptive Potential: Latitudinal variation in thermal tolerance in the copepod Tigriopus californicus?

University Of California-Davis, Davis CA

Investigators

Abstract

The rapid pace of climate change threatens many species with extinction. A species may avoid extinction if it is able to either 1) shift its geographic distribution to track the changing environment, or 2) evolve greater tolerance of new conditions. The ability of a species to adapt to a changing environment will depend on the amount of genetic variation for traits like tolerance of extreme temperatures. However, very little is known about how much variation exists for these kinds of traits in nature. The PIs will address these issues using the shrimp-like tidepool animal, Tigriopus californicus, as a representative study organism. This tiny marine crustacean lives in upper shore tidepools along the Pacific coast of North America. The PIs are collecting Tigriopus from eight sites spanning over 900 miles to establish 30 laboratory populations. Their experiments will expose these populations to increasing temperatures for multiple generations, to track the course of population changes in response to environmental change. These experiments will measure genetic variation for temperature tolerance and will test the capacity for an evolutionary response to warming temperatures. The student PI has been very successful in mentoring undergraduates and will continue to involve them in the research. This project will add to the understanding of the role of evolution in contributing to a species' ability to avoid extinction in the face of climate change. By describing geographic variation in an important trait, the results of this project will also provide managers with a valuable decision-making tool when prioritizing habitats and populations for conservation.