title: Genomic Patterns of Geographic Differentiation in Drosophila simulans.
abstract: Geographic patterns of genetic differentiation have long been used to understand population history and to learn about the biological mechanisms of adaptation. Here we present an examination of genomic patterns of differentiation between northern and southern populations of Australian and North American Drosophila simulans, with an emphasis on characterizing signals of parallel differentiation. We report on the genomic scale of differentiation and functional enrichment of outlier SNPs. While, overall, signals of shared differentiation are modest, we find the strongest support for parallel differentiation in genomic regions that are associated with regulation. Comparisons to Drosophila melanogaster yield potential candidate genes involved in local adaptation in both species, providing insight into common selective pressures and responses. In contrast to D. melanogaster, in D. simulans we observe patterns of variation that are inconsistent with a model of temperate adaptation out of a tropical ancestral range, highlighting potential differences in demographic and colonization histories of this cosmopolitan species pair.
authors.affiliation: Department of Evolution and Ecology, University of California, Davis, California 95616 Center for Population Biology, University of California, Davis, California 95616 sedghifar@ucdavis.edu.
authors.forename: Alisa
authors.initials: A
authors.lastname: Sedghifar
authors.affiliation: Department of Evolution and Ecology, University of California, Davis, California 95616.
authors.forename: Perot
authors.initials: P
authors.lastname: Saelao
authors.affiliation: Department of Evolution and Ecology, University of California, Davis, California 95616 Center for Population Biology, University of California, Davis, California 95616.
authors.forename: David J
authors.initials: DJ
authors.lastname: Begun
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics; D000818:Animals; D001315:Australia; D000067636:Drosophila simulans / Q000235:genetics*; D005260:Female; D005828:Genetics, Population; D049750:Genome, Insect; D009656:North America; D020641:Polymorphism, Single Nucleotide
keywords: Drosophila; geographic variation; population genomics