PARENT SESSION
Organized Oral Session 45: Evolution in metacommunities: A new framework for species coexistence
Organizer(s): MC Urban and MA Leibold
Thursday, August 11, 8:00 AM - 11:30 AM, Meeting Room 516 A, Level 5, Palais des congrès de Montréal
Rapid evolution and the convergence of ecological and evolutionary time.
Hairston, Nelson*,1, Ellner, Stephen1, Geber, Monica1, Yoshida, Takehito1, Fox, Jennifer1, 1 Department of Ecology and Evolutionary Biology, Ithaca, New York, USA
ABSTRACT- Larry Slobodkin (1961) drew a distinction between ecological time and evolutionary time that formalized a hypothesized substantial difference in the rates at which ecological and evolutionary processes take place. Many recent studies have, however, found rates of evolutionary change often characterized as rapid. Although rapid is often left undefined in these studies (including our own), we propose that what is commonly meant is adaptive genetic change occurring on a time scale approaching the rate at which ecological dynamics occur. We have developed a method for comparing ecological and evolutionary rates that can be applied to examples for which long-term data are available. It assesses the relative contributions of environmental change (ecology) and organism-trait change (evolution) to change in organism fitness. We apply this approach to three systems: an algal-defense/nutrient-uptake tradeoff in laboratory rotifer-algal microcosms, diapause-timing changes by freshwater copepods in response to fish predation in a natural lake, and the Grants (2002) data on bill-size changes in Darwins finches in response to rain fall on the Galapagos Islands. In each case, the rate of evolutionary change is of the same order as that of ecological change, but with interesting differences in the perspective obtained through this analysis.
Key words: Brachionus rotifers, Chlorella algae, Geospiza finches, diaptomid copepods