title: Parallel geographic variation in Drosophila melanogaster.
abstract: Drosophila melanogaster, an ancestrally African species, has recently spread throughout the world, associated with human activity. The species has served as the focus of many studies investigating local adaptation relating to latitudinal variation in non-African populations, especially those from the United States and Australia. These studies have documented the existence of shared, genetically determined phenotypic clines for several life history and morphological traits. However, there are no studies designed to formally address the degree of shared latitudinal differentiation at the genomic level. Here we present our comparative analysis of such differentiation. Not surprisingly, we find evidence of substantial, shared selection responses on the two continents, probably resulting from selection on standing ancestral variation. The polymorphic inversion In(3R)P has an important effect on this pattern, but considerable parallelism is also observed across the genome in regions not associated with inversion polymorphism. Interestingly, parallel latitudinal differentiation is observed even for variants that are not particularly strongly differentiated, which suggests that very large numbers of polymorphisms are targets of spatially varying selection in this species.
authors.affiliation: Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599.
authors.forename: Josie A
authors.initials: JA
authors.lastname: Reinhardt
authors.forename: Bryan
authors.initials: B
authors.lastname: Kolaczkowski
authors.forename: Corbin D
authors.initials: CD
authors.lastname: Jones
authors.forename: David J
authors.initials: DJ
authors.lastname: Begun
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Kern
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000235:genetics*; D019143:Evolution, Molecular; D017344:Genes, Insect / Q000235:genetics; D023281:Genomics; D019476:Insect Proteins / Q000235:genetics; D058974:Phylogeography; D020641:Polymorphism, Single Nucleotide; D012641:Selection, Genetic
chemical_list: D019476:Insect Proteins
keywords: adaptation; clinal variation; population genomics