Sceloporus variabilis

Number of Pages: 3Integrative BiologyGeological Science

Quaternary range and demographic expansion of Liolaemus darwinii (Squamata: Liolaemidae) in the Monte Desert of Central Argentina using Bayesian phylogeography and ecological niche modelling

Until recently, most phylogeographic approaches have been unable to distinguís between demographic and range expansion processes, making it difficult to test for the possibility of range expansion without population growth and vice versa. In this study, we applied a Bayesian phylogeographic approach to reconstruct both demographic and range expansion in the lizard Liolaemus darwinii of the Monte Desert in Central Argentina, during the Late Quaternary. Based on analysis of 14 anonymous nuclear loci and the cytochrome b mitochondrial DNA gene, we detected signals of demographic expansion starting at ~55 ka based on Bayesian Skyline and Skyride Plots. In contrast, Bayesian relaxed models of spatial diffusion suggested that range expansion occurred only between ~95 and 55 ka, and more recently, diffusion rates were very low during demographic expansion. The possibility of population growth without substantial range expansion could account for the shared patterns of demographic expansion during the Last Glacial Maxima (OIS 2 and 4) in fish, small mammals and other lizards of the Monte Desert. We found substantial variation in diffusion rates over time, and very high rates during the range expansion phase, consistent with a rapidly advancing expansion front towards the southeast shown by palaeo-distribution models. Furthermore, the estimated diffusion rates are congruent with observed dispersal rates of lizards in field conditions and therefore provide additional confidence to the temporal scale of inferred phylogeographic patterns. Our study highlights how the integration of phylogeography with palaeo-distribution models can shed light on both demographic and range expansion processes and their potential causes.Fil: Camargo Bentaberry, Arley. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Werneck, Fernanda P.. Brigham Young University. Life Science Museum. Department of Biology & Bean; Estados Unidos. Universidade de Brasılia. Departamento de Zoologia; BrasilFil: Morando, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Sites Jr., Jack W.. Brigham Young University. Life Science Museum. Department of Biology & Bean; Estados UnidosFil: Avila, Luciano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Lagartijas de la provincia de Santa Cruz, Argentina: distribución geográfica, diversidad genética y estado de conservación

Este trabajo resume las características geográficas, genéticas y de conservación de los saurios de la provincia de Santa Cruz; se presentan también comentarios acerca del estado del arte de la investigación en la provincia y las perspectivas futuras de los mismos. Utilizando ~ 1500 registros de presencia, se realiza un inventario biológico actualizado y se incluyen mapas de distribución, fotografías de las especies, comentarios genéticos y estatus de conservación para las lagartijas de Santa Cruz. El número de especies de lagartijas distribuidas en esta provincia es de 29 (27 especies y dos subespecies), sin embargo tres de éstas no presentan registros actuales. En base a los patrones genéticos se identifican al menos diez especies candidatas, linajes no descriptos que poseen suficiente diferenciación genética como para representar especies nuevas, cuyo estatus específico tiene que ser evaluado en futuras investigaciones. Este trabajo combina la información tradicionalmente presentada en inventarios biológicos con información genética, de distribución y estatus de conservación. Más allá de la novedosa integración realizada, este trabajo tiene la potencialidad de guiar el desarrollo de estudios detallados, en los que se puedan identificar (entre otras) zonas tanto para conservación como para explotación sustentable, así como también puede acelerar la descripción de nuevos taxa llenando los vacíos en el conocimiento de la taxonomía alfa.In this paper we present a revision of the geographic distribution, genetic characteristics and conservation status of lizards from the Santa Cruz province. We summarize the state-of-the-art knowledge base and future perspectives of herpetological research in this province. We present an updated checklist using ~1500 records of lizards, and include distributional maps, species photographs, comments on genetic variability and the conservation status of all recognized species. Twenty-nine species of lizards (26 species and 3 subspecies) are cited for this territory, although three of them lack of recent references, and from the genetic patterns we identify at least ten candidate species. These are defined as non-described lineages characterized by suffi - cient genetic differentiation to likely represent new species, but intensive taxonomic work is needed in order to confirm their specific status. In combining traditional information presented in checklists with genetic data, distributional patterns, and conservation status, we hope that this novel data integration approach will lead other investigators to develop similar studies. These types of studies represent the first step towards identification of priority conservation areas, as well as identification of those that are more appropriate for intense anthropogenic use; moreover this study will accelerate the description of new taxa, thereby filling gaps in alpha taxonomic knowledge.Fil: Breitman, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Minoli, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Avila, Luciano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Medina, Cintia Débora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Sites Jr., Jack W.. University Brigham Young; Estados UnidosFil: Morando, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Phylogenetic insights on evolutionary novelties in lizards and snakes: sex, birth, bodies, niches

Abstract Squamate reptiles (lizards and snakes) are a diverse clade in which there appear to have been multiple origins of many remarkable traits, including (a) parthenogenetic reproduction, (b) viviparity, (c) snake-like, limb-reduced body form, (d ) herbivory, and (e) venom. These repeated transitions make squamates an outstanding/excellent system for addressing many fundamental questions in evolutionary biology. For example, they are the only vertebrate group with true parthenogenesis (with at least 40 separate origins), they have more origins of viviparity than any other group of vertebrates, and they have undergone dramatic changes in body form (lizard-like to snake-like) dozens of times. New molecular phylogenies for squamates have overturned many traditional hypotheses and taxonomies based on morphology and are now revealing exciting new insights into the evolution of many of these traits at both higher and lower taxonomic levels. In this review, we summarize many of these new insights and outline important areas for future research

Molecular phylogeny of the “salty” <i>Liolaemus</i> species (Reptilia: Squamata): <i>anomalus</i> group, endemic of the Argentina Monte Desert

In Argentina, the Monte ecoregion extends for more than 2,000 km from NW Argentina to boreal Patagonia, and includes many salt-pans and barren flatlands colonized by the monophyletic Liolaemus anomalus group that includes seven species. Some of their external morphological characteristics and behaviors are very unusual for the genus, and this has led to a complex taxonomic history. The group is very poorly known except for a recent paper with descriptions of three species and morphological-based phylogenetic hypotheses. Of the four recognized species, two are threatened and one is vulnerable, and while the conservation status of the three recently described species is unknown, they are suspected to also be under some degree of threat. We reviewed all georeferenced localities known to produce a distribution map, and sequenced two mitochondrial and four nuclear genes, for representatives of all species. We inferred a time-calibrated species tree showing that the evolutionary history of this clade occurred entirely during the Pleistocene, with most of the divergences very recent. The climatic and geomorphological changes driving this divergence started during the Great Patagonian Glaciation, initially separating the two northwestern-most distributed species (L. pipanaco + L. pseudoanomalus) from the rest. Given the very recent evolutionary history of the group and their unique and conserved morphology, incongruent topologies among datasets are expected; a detailed genome-wide dataset will be needed to fully assess and resolve their speciation history.En Argentina, la ecorregión de Monte se extiende por más de 2.000 km desde el noroeste de Argentina hasta la Patagonia boreal, e incluye muchas salinas y llanuras áridas colonizadas por el grupo monofilético Liolaemus anomalus que incluye siete especies. Algunas de sus características y comportamientos morfológicos externos son muy inusuales para el género y esto dio lugar a una compleja historia taxonómica. Recientemente se describieron tres nuevas especies y se propusieron hipótesis filogenéticas basadas en morfología. Desde el punto de vista de su conservación, solo cuatro están categorizadas, dos amenazadas y una vulnerable, y aunque se desconoce el estado de conservación de las tres últimas especies descritas, se sospecha que se encuentran bajo algún grado de amenaza. Revisamos todas las localidades georreferenciadas conocidas para producir un mapa de distribución, y secuenciamos dos genes mitocondriales y cuatro nucleares, para representantes de todas las especies. Inferimos un árbol de especies calibrado en el tiempo que muestra que la historia evolutiva de este clado ocurrió en su totalidad durante el Pleistoceno, siendo la mayoría de las divergencias muy recientes. Los cambios climáticos y geomorfológicos que impulsaron esta divergencia ocurrieron durante la Gran Glaciación Patagónica, inicialmente separando las dos especies distribuidas más al noroeste (L. pipanaco + L. pseudoanomalus) del resto. Dada la historia evolutiva muy reciente del grupo y su morfología única y conservada, se esperan topologías incongruentes entre los conjuntos de datos. Se necesitará un conjunto de datos detallado de todo el genoma para evaluar y resolver completamente su historia de especiación.Asociación Herpetológica Argentin

Comparing alignment methods for inferring the history of the new world lizard genus Mabuya (Squamata

Abstract The rapid increase in the ability to generate molecular data, and the focus on model-based methods for tree reconstruction have greatly advanced the use of phylogenetics in many Welds. The recent Xurry of new analytical techniques has focused almost solely on tree reconstruction, whereas alignment issues have received far less attention. In this paper, we use a diverse sampling of gene regions from lizards of the genus Mabuya to compare the impact, on phylogeny estimation, of new maximum likelihood alignment algorithms with more widely used methods. Sequences aligned under diVerent optimality criteria are analyzed using partitioned Bayesian analysis with independent models and parameter settings for each gene region, and the most strongly supported phylogenetic hypothesis is then used to test the hypothesis of two colonizations of the New World by African scincid lizards. Our results show that the consistent use of model-based methods in both alignment and tree reconstruction leads to trees with more optimal likelihood scores than the use of independent criteria in alignment and tree reconstruction. We corroborate and extend earlier evidence for two independent colonizations of South America by scincid lizards. Relationships within South American Mabuya are found to be in need of taxonomic revision, speciWcally complexes under the names M. heathi, M. agilis, and M. bistriata (sensu, M.T. Rodrigues, Papeis Avulsos de Zoologia 41 (2000) 313)

Comparing alignment methods for inferring the history of the new world lizard genus Mabuya (Squamata

Abstract The rapid increase in the ability to generate molecular data, and the focus on model-based methods for tree reconstruction have greatly advanced the use of phylogenetics in many Welds. The recent Xurry of new analytical techniques has focused almost solely on tree reconstruction, whereas alignment issues have received far less attention. In this paper, we use a diverse sampling of gene regions from lizards of the genus Mabuya to compare the impact, on phylogeny estimation, of new maximum likelihood alignment algorithms with more widely used methods. Sequences aligned under diVerent optimality criteria are analyzed using partitioned Bayesian analysis with independent models and parameter settings for each gene region, and the most strongly supported phylogenetic hypothesis is then used to test the hypothesis of two colonizations of the New World by African scincid lizards. Our results show that the consistent use of model-based methods in both alignment and tree reconstruction leads to trees with more optimal likelihood scores than the use of independent criteria in alignment and tree reconstruction. We corroborate and extend earlier evidence for two independent colonizations of South America by scincid lizards. Relationships within South American Mabuya are found to be in need of taxonomic revision, speciWcally complexes under the names M. heathi, M. agilis, and M. bistriata (sensu, M.T. Rodrigues, Papeis Avulsos de Zoologia 41 (2000) 313)

Lagartijas de la provincia de Santa Cruz, Argentina: distribución geográfica, diversidad genética y estado de conservación

Este trabajo resume las características geográficas, genéticas y de conservación de los saurios de la provincia de Santa Cruz; se presentan también comentarios acerca del estado del arte de la investigación en la provincia y las perspectivas futuras de los mismos. Utilizando ~ 1500 registros de presencia, se realiza un inventario biológico actualizado y se incluyen mapas de distribución, fotografías de las especies, comentarios genéticos y estatus de conservación para las lagartijas de Santa Cruz. El número de especies de lagartijas distribuidas en esta provincia es de 29 (27 especies y dos subespecies), sin embargo tres de éstas no presentan registros actuales. En base a los patrones genéticos se identifican al menos diez especies candidatas, linajes no descriptos que poseen suficiente diferenciación genética como para representar especies nuevas, cuyo estatus específico tiene que ser evaluado en futuras investigaciones. Este trabajo combina la información tradicionalmente presentada en inventarios biológicos con información genética, de distribución y estatus de conservación. Más allá de la novedosa integración realizada, este trabajo tiene la potencialidad de guiar el desarrollo de estudios detallados, en los que se puedan identificar (entre otras) zonas tanto para conservación como para explotación sustentable, así como también puede acelerar la descripción de nuevos taxa llenando los vacíos en el conocimiento de la taxonomía alfa.In this paper we present a revision of the geographic distribution, genetic characteristics and conservation status of lizards from the Santa Cruz province. We summarize the state-of-the-art in herpetological research, as well as future directions for research in this province. We present an updated checklist using ~1500 records of lizards, and include distributional maps, species photographs, comments on genetic variability and the conservation status of all recognized taxa. Twenty-nine species of lizards (27 species and two subspecies) are cited for this territory, although three of them lack of recent references, and from the genetic patterns we identify at least ten candidate species. These are defined as non-described lineages characterized by sufficient genetic differentiation to likely represent new species, but intensive taxonomic work is needed in order to confirm their specific status. In combining traditional information presented in checklists with genetic data, distributional patterns, and conservation status, we hope that this novel data integration approach will lead other investigators to develop similar studies. These types of studies represent the first step towards identification of priority conservation areas, as well as identification of those that are more appropriate for intense anthropogenic use; moreover this study will accelerate the description of new taxa, thereby filling gaps in alpha taxonomic knowledge.Asociación Herpetológica Argentina (AHA

Lagartijas de la provincia de Santa Cruz, Argentina: distribución geográfica, diversidad genética y estado de conservación

Este trabajo resume las características geográficas, genéticas y de conservación de los saurios de la provincia de Santa Cruz; se presentan también comentarios acerca del estado del arte de la investigación en la provincia y las perspectivas futuras de los mismos. Utilizando ~ 1500 registros de presencia, se realiza un inventario biológico actualizado y se incluyen mapas de distribución, fotografías de las especies, comentarios genéticos y estatus de conservación para las lagartijas de Santa Cruz. El número de especies de lagartijas distribuidas en esta provincia es de 29 (27 especies y dos subespecies), sin embargo tres de éstas no presentan registros actuales. En base a los patrones genéticos se identifican al menos diez especies candidatas, linajes no descriptos que poseen suficiente diferenciación genética como para representar especies nuevas, cuyo estatus específico tiene que ser evaluado en futuras investigaciones. Este trabajo combina la información tradicionalmente presentada en inventarios biológicos con información genética, de distribución y estatus de conservación. Más allá de la novedosa integración realizada, este trabajo tiene la potencialidad de guiar el desarrollo de estudios detallados, en los que se puedan identificar (entre otras) zonas tanto para conservación como para explotación sustentable, así como también puede acelerar la descripción de nuevos taxa llenando los vacíos en el conocimiento de la taxonomía alfa.In this paper we present a revision of the geographic distribution, genetic characteristics and conservation status of lizards from the Santa Cruz province. We summarize the state-of-the-art in herpetological research, as well as future directions for research in this province. We present an updated checklist using ~1500 records of lizards, and include distributional maps, species photographs, comments on genetic variability and the conservation status of all recognized taxa. Twenty-nine species of lizards (27 species and two subspecies) are cited for this territory, although three of them lack of recent references, and from the genetic patterns we identify at least ten candidate species. These are defined as non-described lineages characterized by sufficient genetic differentiation to likely represent new species, but intensive taxonomic work is needed in order to confirm their specific status. In combining traditional information presented in checklists with genetic data, distributional patterns, and conservation status, we hope that this novel data integration approach will lead other investigators to develop similar studies. These types of studies represent the first step towards identification of priority conservation areas, as well as identification of those that are more appropriate for intense anthropogenic use; moreover this study will accelerate the description of new taxa, thereby filling gaps in alpha taxonomic knowledge.Asociación Herpetológica Argentina (AHA