title: Pattern of genetic differentiation of an incipient speciation process: The case of the high Andean killifish Orestias.
abstract: During the Pleistocene and Holocene, the southwest Andean Altiplano (17°-22°S) was affected by repeated fluctuations in water levels, high volcanic activity and major tectonic movements. In the early Holocene the humid Tauca phase shifted to the arid conditions that have lasted until the present, producing endorheic rivers, lakes, lagoons and wetlands. The endemic fish Orestias (Cyprinodontidae) represents a good model to observe the genetic differentiation that characterizes an incipient speciation process in allopatry since the morphospecies described inhabit a restricted geographic area, with present habitat fragmentation. The genetic diversity and population structure of four endemic morphospecies of Orestias (Cyprinodontidae) found in the Lauca National Park (LNP) analyzed with mitochondrial markers (Control Region) and eight microsatellites, revealed the existence of genetic groups that matches the fragmentation of these systems. High values of genetic and phylogeographic differentiation indices were observed between Chungará Lake and Piacota lagoon. The group composed of the Lauca River, Copapujo and Chuviri wetlands sampling sites showed a clear signal of expansion, with a star-like haplotype network. Levels of genetic differentiation were lower than in Chungará and Piacota, suggesting that these localities would have differentiated after the bottlenecks linked to the collapse of Parinacota volcano. The Parinacota sample showed a population signal that differed from the other localities revealing greater genetic diversity and a disperse network, presenting haplotypes shared with other LNP localities. A mixing pattern of the different genetic groups was evident using the microsatellite markers. The chronology of the vicariance events in LNP may indicate that the partition process of the Orestias populations was gradual. Considering this, and in view of the genetic results, we may conclude that the morphospecies from LNP are populations in ongoing differentiation process.
authors.affiliation: Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Ñuñoa, Santiago, Región Metropolitana, Chile.|Escuela de Medicina Veterinaria, Facultad de Recursos Naturales y Medicina Veterinaria, Universidad Santo Tomás, Talca, Región del Maule Chile.|Escuela de Medicina Veterinaria, Facultad de Recursos Naturales y Ciencias Silvoagropecuarias, Universidad Iberoamericana de Ciencias y Tecnología, Santiago, Santiago, Región Metropolitana, Chile.
authors.forename: Claudia Jimena
authors.initials: CJ
authors.lastname: Guerrero-Jiménez
authors.affiliation: Faculty of Life Science, Utrecht University, Utrecht, Netherlands.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Peña
authors.affiliation: Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Ñuñoa, Santiago, Región Metropolitana, Chile.
authors.forename: Pamela
authors.initials: P
authors.lastname: Morales
authors.affiliation: Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Ñuñoa, Santiago, Región Metropolitana, Chile.
authors.forename: Marco
authors.initials: M
authors.lastname: Méndez
authors.affiliation: Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Ñuñoa, Santiago, Región Metropolitana, Chile.
authors.forename: Michel
authors.initials: M
authors.lastname: Sallaberry
authors.affiliation: Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Ñuñoa, Santiago, Región Metropolitana, Chile.
authors.forename: Irma
authors.initials: I
authors.lastname: Vila
authors.affiliation: Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Ñuñoa, Santiago, Región Metropolitana, Chile.|Instituto de Ecología y Biodiversidad de Chile, Universidad de Chile, Ñuñoa, Santiago, Región Metropolitana, Chile.
authors.forename: Elie
authors.initials: E
authors.lastname: Poulin
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002677:Chile; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D040961:Genetic Drift; D049810:Genetic Speciation; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D006239:Haplotypes; D007695:Killifishes / Q000235:genetics*; D018895:Microsatellite Repeats; D010802:Phylogeny; D058974:Phylogeography; D045483:Rivers
chemical_list: D004272:DNA, Mitochondrial