Meeting Abstract

130-6  Thursday, Jan. 7 14:45  Natural variation in embryonic thermal tolerance among populations of Drosophila melanogaster along a thermal gradient LOCKWOOD, B. L.; University of Vermont Brent.Lockwood@uvm.edu http://www.uvm.edu/~bllockwo/

Early development is predicted to be canalized to produce discrete phenotypes even in the face of environmental perturbation. Contrary to this paradigm, we find that there is significant variation in nature for tolerance to acute thermal stress in embryos of Drosophila melanogaster. We also find that phenotypic variation in embryonic thermal tolerance is continuous, not discrete. We discuss the implications of these findings in the context of natural selection for increased embryonic thermal tolerance in spatially and temporally variable thermal habitats. Ultimately, our results suggest that natural selection leads to population divergence of a developmental physiological trait.