Research overview
Why are individuals in a population different from each other? Answering this question is a central goal of evolutionary biology and can be addressed by studying characteristics of individuals, features of their environment, and their genomes. The Bergland lab address this basic question by studying how temporal and spatial fluctuations in selection pressures maintain genetic variation underlying fitness related traits. The maintenance of functional genetic variation via environmental fluctuations through time and space is a form of natural selection called balancing selection and occurs when some genotypes are better in some environments than others. The Bergland lab seeks to study features of this conditionally beneficial genetic variation with the goal of testing the importance of environmental variation as a diversifying evolutionary force. We address the basic problem of balancing selection using two model systems, Drosophila and Daphnia. These species experience strong fluctuations in selection pressure over seasonal time scales providing us the opportunity to study adaptive evolution as it unfolds in the wild.
Current project - Genetics of Seasonal Adaptation in flies. We study the genetic signatures of seasonal adaptation in Drosophila flies, focusing on Drosophila melanogaster and its close relatives. This work utilizes population genomic inference of seasonal evolution as well as functional characterization of seasonal loci.
Current project - Seasonal metapopulation dynamics of flies. We work at multiple field sites throughout Virginia including orchards and backyard compost piles to collect flies in order to study how habitat differences and seasonal population booms and busts affect the evolutionary process.
Current project - Worldwide Drosophila population genomics. The Bergland participates in several consortia, DrosRTEC and DrosEU, whose aim is to sample and resequence fly populations on multiple continents and over decadal time scales. Such efforts will provide valuable information to the broader community about the dynamic process of adaptation in the wild. Lean more here.
Current project - Local adaptation in dormancy. We study the dormancy strateigies of Daphnia pulex and focus on the entry and timing of embryonic diapause. This work considers how dormancy strategies evolve across ephemerality gradients.