Browsing by Author "Rodriguez-Serrano, Enrique"

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    Genetic variability and structure of the Olive Field Mouse: a sigmodontine rodent in a biodiversity hotspot of southern Chile
    (2019) Zepeda, Paulo S.; Rodriguez-Serrano, Enrique; Torres-Perez, Fernando; Celis-Diez, Juan L.; Eduardo Palma, R.
    The temperate rainforests of southern Chile, a recognized biodiversity hotspot, were significantly affected by Pleistocene glacial cycles in their southern portion and have been severely disrupted mainly due to recent human activities. Additionally, the landscape is characterized by a series of potential barriers to gene flow, such as the Chacao Channel, Cordillera de Piuche in Chiloe and both the Ancud and the Corcovado gulfs. We used mitochondrial DNA sequences and microsatellite data across several populations to evaluate the genetic variability and structure of the sigmodontine rodent Abrothrix olivacea brachiotis, one of the most common species of small mammals and an inhabitant of these biodiverse forests. Sequencing data showed that along with the recovery of high haplotype variation for this species, there was a low nucleotide diversity between haplotypes, showing no genetic differences between the Chiloe Island and continental populations in southern Chile or through any other geographic barrier in the study area. However, microsatellite data exhibited some level of population structuring. The most evident clusterings were those of the Chiloe Island and that of North Patagonia. These findings are corroborated by a barrier analysis that showed a genetic barrier in the latter areas, whereas the Chacao Channel was not a significant barrier for this rodent. Overall, the genetic variability and structure of A. o. brachiotis was concordant with historical factors, such as the Last Glacial Maximum and the presence of geographic elements that isolate populations.
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    Molecular phylogeography of Abrothrix olivaceus (Rodentia: Sigmodontinae) in Chile
    (2006) Rodriguez-Serrano, Enrique; Cancino, Ricardo A.; Palma, R. Eduardo
    Abrothrix olivaceus is the most abundant and widespread species of sigmodontine rodent in Chile. We evaluated phylogeographic relationships within A. olivaceous based on analyses of 67 specimens collected along most of the distributional range of the species. We used nucleotide sequence data from the hypervariable domain I of the mitochondrial DNA control region. Examination of our data supports a northern origin for this taxon, followed by southward dispersal. Also, we propose the occurrence of a new subspecies of A. olivaceus in the northernmost limit of the species' range. We detected a significant influence of recent paleoclimatic events on the current distribution of A. olivaceus, particularly in south-central Chile. The results also support the genetic distinctness of nominal subspecies proposed in the classical literature.
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    Morphological and molecular characterization of Perinereis gualpensis (Polychaeta: Nereididae) and its phylogenetic relationships with other species of the genus off the Chilean coast, Southeast Pacific
    (2013) Sampertegui, Sandra; Rozbaczylo, Nicolas; Canales-Aguirre, Cristian B.; Carrasco, Franklin; Hernandez, Cristian E.; Rodriguez-Serrano, Enrique
    The genus Perinereis, family Nereididae, consists of approximately 66 worldwide distributed species with marine, estuarine, and freshwater representatives. The objective of this study is to use morphological and molecular traits to evaluate the taxonomic differentiation of the estuarine polychaete P gualpensis. Also we reconstruct the phylogenetic relationships between P gualpensis and congeneric species recorded in Chilean coast: P. falklandica, P. longidonta and, especially with the morphologically most similar species, P vallata. Phylogenetic analyses based on molecular and morphological characters allow us to validate P. gualpensis and P. vallata as two independent and clearly defined species. Consequently, the taxonomic confusion about the possible sibling species P. gualpensis and P. vallata is completely resolved. However, morphological and genetic data are partially incongruent about the phylogenetic relationships of these four Perinereis species. We concluded that different evolutionary process that affect the morphological and genetics data produce different answers. Also we propose the use of new molecular evidence arising from molecular markers with different nucleotide substitution rate to that used here.
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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; Zuniga-Reinoso, Alvaro; Cancino, Ricardo A.; Gonzalez-Acuna, Daniel; Rodriguez-Serrano, Enrique; Eduardo Palma, R.; Hernandez, Cristian E.
    Only two species of Didelphidae are currently recognized in Chile, the sister species Thylamys elegans, endemic of Mediterranean ecorregion and Thylamys pallidior, the inhabitant of the Puna and desert canyons. Three subspecies have been described for T. elegans: T. e. elegans, T. e. coquimbensis and T. e. soricinus. However, a recent study based on morphological analyses, synonymized T. elegans coquimbensis from the Coquimbo valleys (30-31 degrees S) with T. pallidior and proposed that T. elegans and T. pallidior could be in sympatry at Coquimbo valleys between Fray Jorge (30 degrees 40'S) and Paiguano (30 degrees 02'S). We assess the current definition of T. e. coquimbensis and T. e. elegans, as well as this taxonomical conflict among the mouse opossums from the Coquimbo valleys through phylogenetic analyses of cytochrome b mitochondrial gene sequences. In this study, for the first time, we used specimens from the type localities of T. e. coquimbensis and T. e. elegans. In addition, we analyzed diagnostic cranial structures for this taxonomic revision. The results supported two allopatric clades, allowing us to keep the taxonomic definition of T. e. elegans and T. e. coquimbensis as phylogenetic reciprocal monophyletic clades and polyphyletic with T. pallidior. This result corroborates previous morphological analyses, which support that mouse opossums from the Coquimbo valleys are T. e. coquimbensis, thus extending its geographic distribution to the coast of Coquimbo and Atacama regions. We don't have evidence for sympatric distribution between T. elegans and T. pallidior in the Coquimbo region.
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    The importance of the Andes in the evolutionary radiation of Sigmodontinae (Rodentia, Cricetidae), the most diverse group of mammals in the Neotropics
    (2023) Vallejos-Garrido, Paulo; Pino, Kateryn; Espinoza-Aravena, Nicolas; Pari, Alexander; Inostroza-Michael, Oscar; Toledo-Munoz, Macarena; Castillo-Ravanal, Boris; Romero-Alarcon, Viviana; Hernandez, Cristian E.; Palma, R. Eduardo; Rodriguez-Serrano, Enrique
    The Andean mountains stand out for their striking species richness and endemicity that characterize many emblematic Neotropical clades distributed in or around these mountains. The radiation of the Sigmodontinae subfamily, the most diversified mammalian group in the Neotropics, has been historically related to Andean orogenesis. We aim to evaluate this interplay between geological processes and biological responses through the diversification dynamics, the biogeographical history, and the range evolution of the subfamily. For these, we built the most comprehensive phylogeny and gathered 14,836 occurrences for the subfamily. We identified one shift in the speciation rate in the genus Akodon, which suffered their Andean radiation after the arrival of non-Andean ancestors. Our biogeographic analyses show multiple dispersal paths throughout the evolution that allowed this subfamily to colonize all Neotropics. The Northern Andes and Central-Southern Andes were the most important sources of diversity. In addition, the Central-Southern Andes were the most relevant sink, receiving the highest number of lineages. The Andean region exhibited higher speciation and turnover rates than non-Andean regions. Thus, our results support the crucial role of the Andean Mountains in the Sigmodontinae radiation, acting as a "macroevolutionary cradle" and "species attractor" for several sigmodontine lineages at different times, and as a "species pump" becoming the biogeographic source of multiple widely distributed neotropical lineages. Then, complex macroevolutionary dynamics would explain these rodents' high extant Andean diversity and their wide distribution in the Neotropics.