title: Ecological range shift in the polyploid members of the South American genus Fosterella (Bromeliaceae).
abstract: The distribution of polyploidy along a relatively steep Andean elevation and climatic gradient is studied using the genus Fosterella L.B. Sm. (Bromeliaceae) as a model system. Ecological differentiation of cytotypes and the link of polyploidy with historical biogeographic processes such as dispersal events and range shift are assessed.
  
  
  
  4',6-Diamidino-2-phenylindole (DAPI) staining of nuclei and flow cytometry were used to estimate the ploidy levels of 159 plants from 22 species sampled throughout the distribution range of the genus. Ecological differentiation among ploidy levels was tested by comparing the sets of climatic variables. Ancestral chromosome number reconstruction was carried out on the basis of a previously generated phylogeographic framework.
  
  
  
  This study represents the first assessment of intrageneric, intraspecific and partially intrapopulational cytotype diversity in a genus of the Bromeliaceae family. In Fosterella , the occurrence of polyploidy was limited to the phylogenetically isolated penduliflora and rusbyi groups. Cytotypes were found to be ecologically differentiated, showing that polyploids preferentially occupy colder habitats with high annual temperature variability (seasonality). The combined effects of biogeographic history and adaptive processes are presumed to have shaped the current cytotype distribution in the genus.
  
  
  
  The results provide indirect evidence for both adaptive ecological and non-adaptive historical processes that jointly influenced the cytotype distribution in the predominantly Andean genus Fosterella (Bromeliaceae). The results also exemplify the role of polyploidy as an important driver of speciation in a topographically highly structured and thus climatically diverse landscape.
authors.affiliation: Department of Botany and Molecular Evolution, Senckenberg Research Institute and Natural History Museum Frankfurt, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany.
authors.forename: Juraj
authors.initials: J
authors.lastname: Paule
authors.affiliation: Plant Molecular Systematics, Department of Sciences, University of Kassel, D-34132 Kassel, Germany.
authors.forename: Natascha D
authors.initials: ND
authors.lastname: Wagner
authors.affiliation: Plant Molecular Systematics, Department of Sciences, University of Kassel, D-34132 Kassel, Germany.
authors.forename: Kurt
authors.initials: K
authors.lastname: Weising
authors.affiliation: Department of Botany and Molecular Evolution, Senckenberg Research Institute and Natural History Museum Frankfurt, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany.|Institute of Ecology, Evolution and Diversity, Goethe University, Max-von-Laue-Strasse 13, D-60439 Frankfurt am Main, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Zizka
mesh_terms: D000220:Adaptation, Biological; D000531:Altitude; D005075:Biological Evolution; D031229:Bromeliaceae / Q000145:classification* / Q000235:genetics; D002980:Climate; D058974:Phylogeography; D011123:Polyploidy; D013020:South America
keywords: Bromeliaceae; Central Andes; Fosterella; Neotropics; climate; cytotype; disjunction; ecological differentiation; flow cytometry; parapatry; ploidy