Emily L. Behrman

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In many species, genomic data have revealed pervasive adaptive evolution indicated by the fixation of beneficial alleles. However, when selection pressures are highly variable along a species' range or through time adaptive alleles may persist at intermediate frequencies for long periods. So called "balanced polymorphisms" have long been understood to be an(More)
Seasonal environmental heterogeneity is cyclic, persistent and geographically widespread. In species that reproduce multiple times annually, environmental changes across seasonal time may create different selection regimes that may shape the population ecology and life history adaptation in these species. Here, we investigate how two closely related species(More)
Cosmopolitan populations of Drosophila melanogaster have co-opted a form of reproductive diapause to overwinter in northern populations. Polymorphism in the couch potato gene has been implicated in genetic variation for this diapause trait. Using a collection of 20 populations from Florida to Canada and 11 collections from 3 years in a Pennsylvania orchard,(More)
This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Abstract Examples of clinal variation in phenotypes and genotypes across latitudinal transects have served as important models for(More)
Finding the specific nucleotides that underlie adaptive variation is a major goal in evolutionary biology, but polygenic traits pose a challenge because the complex genotype-phenotype relationship can obscure the effects of individual alleles. However, natural selection working in large wild populations can shift allele frequencies and indicate functional(More)
Wild populations of the model organism Drosophila melanogaster experience highly heterogeneous environments over broad geographical ranges as well as over seasonal and annual timescales. Diapause is a primary adaptation to environmental heterogeneity, and in D. melanogaster the propensity to enter diapause varies predictably with latitude and season. Here(More)
Cuticular hydrocarbons (CHCs) are hydrophobic compounds deposited on the arthropod cuticle that are of functional significance with respect to stress tolerance, social interactions and mating dynamics. We characterized CHC profiles in natural populations of Drosophila melanogaster at five levels: across a latitudinal transect in the eastern United States,(More)
Most investigations of the importance of and the determinants of adult cognitive skills assume that (a) they are produced primarily by schooling and (b) schooling is statistically predetermined. But these assumptions may lead to misleading inferences about impacts of schooling and of pre-schooling and post-schooling experiences on adult cognitive skills.(More)