Browsing by Author "Lamborot, Madeleine"

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    Genetic variation within and between four chromosomal races of Liolaemus monticola in Chile
    (2007) Vasquez, Mauricio; Torres-Perez, Fernando; Lamborot, Madeleine
    Allozyme variability was assessed within and between 18 samples of four chromosomal races of the Liolaemus monticola complex: "Southern, 2n=34", "Northern, 2n=38-40", "Multiple Fission, 2n=42-44" and "Northern modified 1, 2n=38-40". This is an endemic montane Chilean lizard characterized by extensive chromosomal polytypy. The population genetic structure was studied by means of allozyme electrophoresis of 20 presumptive loci. Population heterogeneity analysis carried out by the estimation of Weir and Cockerham's F-statistic (theta), demonstrated substantial genetic differentiation among populations. The u-statistic, genetic distance data and multivariate analyses show that genetic variation is distributed into geographically coherent population groups in accordance with three of the four chromosome races. The greatest differentiation occurs between all populations of the "Southern, 2n=34" race and a second group that includes all populations from the "Northern, 2n=38-40" plus "Northern mod 1, 2n=38-40" races, separated from the "Multiple Fissions, 2n=42-44" race. As riverine barriers also separate these chromosomal races, we do not attribute the observed differentiation to isolation-by-distance or the chromosome characterization for each race. Possible routes of migration and colonization are proposed.
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    Systematics and evolutionary relationships of the mountain lizard Liolaemus monticola (Liolaemini): how morphological and molecular evidence contributes to reveal hidden species diversity
    (2009) Torres-Perez, Fernando; Mendez, Marco A.; Benavides, Edgar; Moreno, Rodrigo A.; Lamborot, Madeleine; Palma, R. Eduardo; Ortiz, Juan Carlos
    The delimitation of species is a major issue in systematic biology and has been a re-emerging discipline in the last decade. A number of studies have shown that the use of multiple data sets is critical for the identification of cryptic species, particularly in groups with complex evolutionary histories. Liolaemus monticola is a montane lizard species distributed in central Chile (32 degrees-42 degrees S), with four described subspecies in a latitudinal gradient from north to south: L. m. monticola, L. m. chillanensis, L. monticola ssp. and L. m. villaricensis. In order to test the systematic status and phylogenetic relationships of the taxa included in the L. monticola group, we analysed morphological (morphometric and meristic) and molecular (allozyme and mitochondrial DNA) data sets. The results of the morphological analyses showed that meristic variables correctly assigned individuals with higher accuracy than did morphometric characters. The results of the analyses of allozyme data revealed eight diagnostic loci that are evidence for significant differences among the four L. monticola subspecies. Phylogenetic analyses with mitochondrial DNA data, including additional species, showed that the L. monticola group is polyphyletic. We postulate that the four current subspecies represent independent evolutionary lineages and must be raised to the specific level as L. monticola, L. chillanensis and L. villaricensis. The taxonomic status of the unnamed L. monticola ssp. remains unresolved, although we provide a preliminary proposal. (C) 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 635-650.