title: Phylogeographic structure of the fire ant Solenopsis invicta in its native South American range: roles of natural barriers and habitat connectivity.
abstract: We generated mitochondrial DNA (mtDNA) sequence data from 402 individuals of the fire ant Solenopsis invicta collected from 11 native populations and analyzed these data using a combination of demographic, phylogenetic, and phylogeographic methods to infer features of the evolutionary history of this species. Prior expectations regarding high levels of genetic structure and isolation by distance among populations were supported by the data, but we also discovered several unanticipated patterns. Our analyses revealed a major genetic break between S. invicta mtDNA haplotypes that coincides with the Mesopotamia wetlands region of South America, resulting in two higher level nested clade groupings. In addition, we identified contrasting patterns of genetic differentiation within these two major groups, which may reflect differences in connectivity of suitable habitat in different parts of the native range of S. invicta. Our study represents the first attempt to understand the phylogeographic history of S. invicta across its native range.
authors.affiliation: Department of Entomology, University of Wisconsin-Madison, Wisconsin 53706, USA. meahrens@wisc.edu
authors.forename: Michael E
authors.initials: ME
authors.lastname: Ahrens
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Ross
authors.forename: D DeWayne
authors.initials: DD
authors.lastname: Shoemaker
mesh_terms: D000818:Animals; D001000:Ants / Q000235:genetics*; D001483:Base Sequence; D001499:Bayes Theorem; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics; D003710:Demography; D004777:Environment; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D006239:Haplotypes / Q000235:genetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013020:South America
chemical_list: D017931:DNA Primers; D004272:DNA, Mitochondrial