title: Phylogenetic relationships and macro-evolutionary patterns within the Drosophila tripunctata "radiation" (Diptera: Drosophilidae).
abstract: Despite previous efforts, the evolutionary history of the immigrans-tripunctata clade remains obscure in part due to its hypothesized origin through a rapid radiation. We performed a supermatrix analysis (3,243 base pairs) coupled with richness patterns, environmental phylogenetic signal and radiation tests in order to address phylogenetic relationships and macro-evolutionary hypotheses within this complex group of species. We propose a well-supported evolutionary scenario for the immigrans-tripunctata clade species, in which the tripunctata "radiation" was monophyletic and subdivided into three main lineages: the first including D. pallidipennis (pallidipennis group) imbedded among members of the tripunctata group; the second clustering the cardini and guarani groups; and the third grouping representatives from the tripunctata, calloptera and guaramunu groups. Therefore, we hypothesize that the tripunctata group encompasses a diphyletic taxon, with one clade including the pallidipennis group and the other showing a close affinity to the calloptera and guaramunu groups. Our results also suggest that niche evolution seems to have played a central role in the evolutionary history of the tripunctata species "radiation" allowing effective dispersion and diversification in the Neotropics, possibly in a southwards direction. Although the data as a whole support the notion that this occurred through rapid and successive speciation events, the radiation hypothesis remains to be further corroborated.
authors.affiliation: Programa de Pós-Graduação em Genética e Biologia Molecular, Departamento de Genética, Universidade Federal do Rio Grande do Sul (UFRGS), CP 15053, Porto Alegre, Rio Grande do Sul, 91501-970, Brazil. lizbiogen@gmail.com
authors.forename: Lizandra J
authors.initials: LJ
authors.lastname: Robe
authors.forename: Vera L S
authors.initials: VL
authors.lastname: Valente
authors.forename: Elgion L S
authors.initials: EL
authors.lastname: Loreto
mesh_terms: D000818:Animals; D001938:Brazil; D004330:Drosophila / Q000145:classification / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D019143:Evolution, Molecular; D014644:Genetic Variation; D005843:Geography; D008800:Mexico; D008969:Molecular Sequence Data; D010176:Panama; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D029721:Drosophila Proteins