PARENT SESSION
Poster Session 39: Late Breaking and Newsworthy Posters
Friday, August 12, 8:30 AM - 10:30 AM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Using microsatellite-PCR products to identify evolutionary genetic changes during predator-prey dynamics.

Meyer, Justin^*,1, Ellner, Stephen¹, Hairston, Nelson¹, Jones, Laura ¹, Yoshida, Takehito¹, ¹ Department of Ecology and Evolutionary Biology, Ithaca, NY 14853, USA

ABSTRACT- Rapid evolutionary processes are known to operate at the same time scale as ecological processes and are predicted to alter ecological dynamics substantially. Our previous research using rotifer-algal chemostats has demonstrated that genetic variation within an algal prey can shape the predator-prey dynamics occurring between rotifers and algae. The observed dynamics are predicted by mathematical models to result from clonal frequency changes within the algal population in response to temporal changes in rotifer abundance and nutrient availability. The algal genetic changes alter the nature of the predator-prey relationship. Recently, we have developed molecular genetic methods that allow us to test whether this rapid-evolution mechanism shapes the ecological dynamics occurring between Brachionus cauliflorus (rotifer) and Chlorella vulgaris (alga) in a lab microcosm. We take advantage of microsatellite-DNA variation between obligately asexual C. vulgaris clones and use newly-developed quantitative PCR techniques to quantify clonal frequencies during the course of predator-prey population dynamics. We are able to define temporal changes in the frequencies of two C. vulgaris clones. The two algal clones show a tradeoff between defense against rotifer predation and algal growth rate, which is important to shaping ecological dynamics. With our new system we are able to observe rapid evolution in real time and show how clonal shifts governed by natural selection shape ecological dynamics.

Key words: rapid evolution, predator-prey, dynamics, quantitative PCR