title: The role of historical factors and natural selection in the evolution of breeding systems of Oxalis alpina in the Sonoran desert 'Sky Islands'.
abstract: Pleistocene climatic oscillations are known to influence the patterns of genetic diversity and the distribution of traits that are the target of selection. Here, we combine phylogeographical and ecological niche modelling (ENM) approaches to explore the influence of historical factors (Pleistocene climatic shifts) and natural selection on the evolution of distyly (two floral morphs) from tristyly (three floral morphs) of Oxalis alpina in the Sky Islands of the Sonoran Desert. Molecular data and ENM indicate that historical factors have had a strong influence on the genetic structure and the geographical distribution of reproductive systems of O. alpina. Moreover, genetic results suggest the possibility that distylous populations do not represent a monophyletic group. We propose that the combined effects of natural selection and genetic drift have influenced the tristyly-distyly transition.
authors.affiliation: Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, México Distrito Federal, México.
authors.forename: J
authors.initials: J
authors.lastname: Pérez-Alquicira
authors.affiliation: Departamento de Ecología de la Biodiversidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Hermosillo, Sonora, México.
authors.forename: F E
authors.initials: FE
authors.lastname: Molina-Freaner
authors.affiliation: Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, México Distrito Federal, México.
authors.forename: D
authors.initials: D
authors.lastname: Piñero
authors.affiliation: Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA.
authors.forename: S G
authors.initials: SG
authors.lastname: Weller
authors.affiliation: Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, México Distrito Federal, México.
authors.forename: E
authors.initials: E
authors.lastname: Martínez-Meyer
authors.affiliation: Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Rozas
authors.affiliation: Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, México Distrito Federal, México.
authors.forename: C A
authors.initials: CA
authors.lastname: Domínguez
mesh_terms: D001130:Arizona; D005075:Biological Evolution; D003889:Desert Climate; D017753:Ecosystem; D035264:Flowers / Q000502:physiology*; D040961:Genetic Drift; D014644:Genetic Variation; D006239:Haplotypes; D019684:Magnoliopsida / Q000235:genetics*; D008800:Mexico; D008957:Models, Genetic; D009516:New Mexico; D058974:Phylogeography; D012641:Selection, Genetic