title: Shared genetic diversity across the global invasive range of the monk parakeet suggests a common restricted geographic origin and the possibility of convergent selection.
abstract: While genetic diversity is hypothesized to be an important factor explaining invasion success, there is no consensus yet on how variation in source populations or demographic processes affects invasiveness. We used mitochondrial DNA haplotypic and microsatellite genotypic data to investigate levels of genetic variation and reconstruct the history of replicate invasions on three continents in a globally invasive bird, the monk parakeet (Myiopsitta monachus). We evaluated whether genetic diversity at invasive sites could be explained by (i) the native source populations from which they were derived and (ii) demographic bottlenecks during introduction. Genetic data indicated a localized source area for most sampled invasive populations, with limited evidence for admixing of native source populations. This pattern largely coincides with historical data on pet trade exports. However, the invasive populations are genetically more similar than predicted from the export data alone. The extent of bottleneck effects varied among invasive populations. The observed low genetic diversity, evidence of demographic contraction and restricted source area do not support the hypothesis that invasion is favoured by the mixing and recombining of genetic variation from multiple source populations. Instead, they suggest that reduced genetic variation through random processes may not inhibit successful establishment and invasion in this species. However, convergent selection across invasive sites could also explain the observed patterns of reduction and similarity in genetic variation and/or the restricted source area. In general, the alternative explanation of intraspecific variation in invasive potential among genotypes or geographic areas is neglected, but warrants more attention as it could inform comparative studies and management of biological invaders.
authors: Department of Molecular Biology and Biochemical Engineering, University Pablo de Olavide, Seville, ES-41013, Spain; Department of Conservation Biology, Estación Biológica de Doñana (CSIC), Avda. Américo Vespucio s/n, Sevilla, 41092, Spain.
authors: Pim
authors: P
authors: Edelaar
authors: Severine
authors: S
authors: Roques
authors: Elizabeth A
authors: EA
authors: Hobson
authors: Anders
authors: A
authors: Gonçalves da Silva
authors: Michael L
authors: ML
authors: Avery
authors: Michael A
authors: MA
authors: Russello
authors: Juan C
authors: JC
authors: Senar
authors: Timothy F
authors: TF
authors: Wright
authors: Martina
authors: M
authors: Carrete
authors: José L
authors: JL
authors: Tella
mesh_terms: D000818:Animals; D004272:DNA, Mitochondrial / Q000235:genetics; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D006239:Haplotypes; D058865:Introduced Species; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D010240:Parakeets / Q000235:genetics*; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial
keywords: bottleneck; founder effect; invasion genetics; native origin; population genetic structure; selection