Browsing by Author "Boric Bargetto, Dusan Vladimir"

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    A comprehensive overview of the genetic diversity in Thylamys elegans (Didelphimorphia : Didelphidae) : establishing the phylogeographic determinants
    (2021) Boric Bargetto, Dusan Vladimir; Zúñiga Reinoso, Álvaro; Inostroza Michel, Óscar; Rodríguez Serrano, Enrique Alfonso; González Acuña, Daniel; Palma Vásquez, Ramón Eduardo; Hernández, Cristián E.
    Background: For the genus Thylamys, the rivers have been reported as barriers to dispersal, limiting current and historical distribution of its lineages. We hypothesized that the Maipo river has affected the genetic structure of northern and southern lineages of Thylamys elegans, recovering a phylogenetic relationships with reciprocally monophyletic sister groups on opposite river banks. We evaluated the role of other rivers in the Mediterranean zone of Chile as historical and recent modulators of the biogeographic processes of this species. Methods: We applied a phylogeographic approach, using the cytochrome-b mitochondrial gene for 93 individuals of T. elegans, from 37 localities in a latitudinal gradient between 21°25’ and 35˚56’S, encompassing a geographic area between the Atacama Desert and most of the Mediterranean Chilean zone. Results: The phylogenetics results recovered six lineages within T. elegans: Thylamys elegans elegans, Thylamys elegans coquimbensis, the Loa lineage and three other lineages not described previously (Aconcagua, South 1 and South 2). We suggest that following rivers play a role like primary barrier: the Maipo river in the genetic differentiation of northern and southern ancestral lineages, and the Mataquito river and its tributary Teno river for the South 1 and South 2 lineages. On the other hand, the Quilimarí river preserve the genetic divergence in T. e. coquimbensis and Aconcagua lineage and the Aconcagua river in Aconcagua lineage and T. e. elegans acting like secondary barriers. Conclusions: We concluded that the genetic diversity and biogeographic history of T. elegans was shaped by mountain glaciers, changes in river water levels during the Pleistocene glaciations and hyperaridity, promoting the differentiation and persistance of the T. elegans lineages.
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    Molecular phylogenetic analyses reveal the importance of taxon sampling in cryptic diversity: Liolaemus nigroviridis and L. monticola (Liolaeminae) as focal species
    (2017) Torres Pérez, Fernando; Palma Vásquez, Ramón Eduardo; Boric Bargetto, Dusan Vladimir; Rodríguez Valenzuela, Evelyn.; Escobar, Constanza.
    Abstract Background Mitochondrial markers are widely used as a first approach in determining evolutionary relationships among vertebrate taxa at different hierarchical scales. Cytochrome b and cytochrome oxidase I are among the most common markers; they are particularly useful in phylogeography and species delineation studies. Simulation and empirical studies show that increasing the taxon sampling has a clear and strong effect on the accuracy of the inferred trees and therefore on hypothesized phylogenetic relationships (and eventually in new taxonomic rearrangements); this should be considered in the design of studies. The lizard genus Liolaemus is widely distributed in southern South America and includes more than 250 described species. The number of taxa and the distribution of Liolaemus species/populations makes them a good model for testing different hypotheses in systematics. Methods We studied two Liolaemus species, Liolaemus nigroviridis and L. monticola as focal species to evaluate their monophyly and the influence of adding new samples from related taxa in the resulting phylogenies. We performed phylogenetic analyses (maximum likelihood and Bayesian inference) using 141 sequences of the mitochondrial DNA Cytochrome b (cyt-b) of 11 Liolaemus species. Results Our study show that using intensive taxon sampling for phylogenetic reconstructions, two species (L. uniformis and L. nitidus) are placed within the clades of the two focal species (L. nigroviridis and L. monticola, respectively). Conclusions Our study confirms the importance of taxon sampling to infer more accurate phylogenetic relationships, particularly to reveal hidden polyphyly or paraphyly, which may have a strong impact on taxonomic proposals and/or inferring cryptic diversity.
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    Phylogenetic evaluation of taxonomic definition of didelphid mouse opossum of the genus Thylamys from valleys of Coquimbo region, Chile.
    (2016) Boric Bargetto, Dusan Vladimir; Zúñiga Reinoso, Alvaro; Cancino, Ricardo A.; González Acuña, Daniel; Rodríguez Serrano, Enrique; Palma Vásquez, Ramón Eduardo; Hernández Ulloa, Cristián Esteban
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    Temporal variation in genetic diversity during an outbreak of Oligoryzomys longicaudatus (Rodentia, Sigmodontinae) in a temperate forest of southern Chile
    (2012) Boric Bargetto, Dusan Vladimir; Jaksic Andrade, Fabián; Palma Vásquez, Ramón Eduardo