Meeting Abstract

123.1  Monday, Jan. 7  Evolution of thermal plasticity in changing environments. CONDON, C*; COOPER, B; YEAMAN, S; ANGILLETTA, M; Arizona State University; Indiana University; University of British Columbia ; Arizona State University chcondon@asu.edu

Environmental fluctuations should favor genotypes that can perform across a broad range of conditions. When these fluctuations occur primarily among generations, developmental plasticity should evolve. Although genotypes from different populations frequently differ in their plasticity, no general support exists for the idea that more environmental variation leads to greater plasticity. We studied the evolution of developmental plasticity in populations of Drosophila melanogaster that had evolved for more than three years in one of four environments: two constant environments (16 and 25°C), a temporally variable environment (alternating between 16 and 25°C each generation), and a spatially variable environment (gene flow between sub-populations at 16 and 25°C). Flies that evolved in the temporally variable environment had greater plasticity of fecundity than those that evolved in constant or spatially variable environments. However, this greater plasticity of fecundity might have come at the cost of poor heat and cold tolerance; flies from the temporally variable lines had shorter survival during heat exposure and slower recovery from cold exposure than did flies from the other selection lines. These results suggest a tradeoff between plasticity and tolerance.