21 research outputs found

    Historical Processes and Genetic Implications of Limb Reduction and Loss in an Island Skink Lineage

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    Evolutionary simplification, or loss of complex characters, is a major theme in studies of body form evolution. The apparently infrequent evolutionary reacquisition of complex characters has led to the assertion (Dollo's Law) that once lost, complex characters may be impossible to re-evolve, at least via the exact same evolutionary process. The spectacular, virtually endemic radiation of Philippine semi-fossorial skinks of the genus Brachymeles represent one of the few radiations of scincid lizards to possess both fully limbed and limbless species. And yet, nothing is known of the phylogenetic relationships of this exceptional group. Morphologically similar body plans have made it difficult to assess species-level diversity, and the genus has long been recognized as one of the more modest radiations of southeast Asian lizards. However, taxonomic studies indicate that the diversity within the genus Brachymeles is grossly underestimated. Here I provide one of the most comprehensive, fine-scale analyses of squamate body-form evolution to date, introducing a new model system of closely related, morphologically variable, lizards. In this study I provide the first robust estimate of phylogenetic relationships within the genus Brachymeles using a multi-locus dataset and nearly complete taxonomic sampling. Systematic revisions guided by robust estimates of phylogeny subsequently result in a 125% increase in species diversity. I provide statistical tests of monophyly for all polytypic species and two widespread limb-reduced species and our results indicate wholesale deviations from past summaries and taxonomic evaluations of the genus. A Bayesian reconstruction of ancestral areas indicates strong statistical support for a minimum of five major dispersal events that have given rise to a major component of the observed species diversity across the archipelago. Our phylogenetic results support independent instances of complete limb loss as well as multiple instances of digit and external ear opening loss and re-acquisition. Even more striking, I find strong statistical support for the re-acquisition of a pentadactyl body form from a digit-reduced ancestor. Our findings have broad, general implications for body form evolution in burrowing vertebrates: whatever constraints have shaped trends in morphological evolution among other squamate groups (excluding Bipes) have been lost in this one exemplary clade

    A new species of Cosmocerca (Nematoda: Cosmoceridae and other helminths in Cyrtodactylus gubaot (Squamata: Gekkonidae) from the Philippines

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    Cosmocerca leytensis sp. nov. (Ascaridida, Cosmocercidae) from the large intestine of Cyrtodactylus gubaot (Squamata: Gekkonidae) collected on Leyte Island, Philippines is described and illustrated. Cosmocerca leytensis sp. nov. is the 30th species assigned to the genus, the 4th from the Oriental region, and the first from the Philippine Islands. The new species is most similar to those species possessing 4 pairs of plectanes, i.e., C. archeyi, C. australis, C. oroensis, and C sardiniae. Cosmocerca sardiniae lacks lateral alae; C. archeyi, C. australis, C. leytensis sp. nov. and C. oroensis possess lateral alae. Spicule length of C. oroensis is less than 75 ĂŹm, while C. archeyi, C. australis, and C. leytensis sp. nov. have spicule lengths greater than 75 ĂŹm. Males of C. australis possess 2 pairs of rosette caudal papillae, which are lacking in C. archeyi and C. leytensis sp. nov. Females of C. archeyi posses a conical tail, females of C. leytensis sp. nov. have a rounded posterior end supporting a flexible filament

    The amphibians and reptiles of Luzon Island, Philippines, VIII: the herpetofauna of Cagayan and Isabela Provinces, northern Sierra Madre Mountain Range

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    A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author’s publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.We provide the first report on the herpetological biodiversity (amphibians and reptiles) of the northern Sierra Madre Mountain Range (Cagayan and Isabela provinces), northeast Luzon Island, Philippines. New data from extensive previously unpublished surveys in the Municipalities of Gonzaga, Gattaran, Lasam, Santa Ana, and Baggao (Cagayan Province), as well as fieldwork in the Municipalities of Cabagan, San Mariano, and Palanan (Isabela Province), combined with all available historical museum records, suggest this region is quite diverse. Our new data indicate that at least 101 species are present (29 amphibians, 30 lizards, 35 snakes, two freshwater turtles, three marine turtles, and two crocodilians) and now represented with well-documented records and/or voucher specimens, confirmed in institutional biodiversity repositories. A high percentage of Philippine endemic species constitute the local fauna (approximately 70%). The results of this and other recent studies signify that the herpetological diversity of the northern Philippines is far more diverse than previously imagined. Thirty-eight percent of our recorded species are associated with unresolved taxonomic issues (suspected new species or species complexes in need of taxonomic partitioning). This suggests that despite past and present efforts to comprehensively characterize the fauna, the herpetological biodiversity of the northern Philippines is still substantially underestimated and warranting of further study

    The amphibians and reptiles of Mindanao Island, southern Philippines, II: the herpetofauna of northeast Mindanao and adjacent islands

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    We summarize all available amphibian and reptile species distribution data from the northeast Mindanao faunal region, including small islands associated with this subcenter of endemic vertebrate biodiversity. Together with all publicly available historical information from biodiversity repositories, we present new data from several major herpetological surveys, including recently conducted inventories on four major mountains of northeast Mindanao, and adjacent islands of Camiguin Sur, Dinagat, and Siargao. We present species accounts for all taxa, comment on unresolved taxonomic problems, and provide revisions to outdated IUCN conservation status assessments in cases where our new data significantly alter earlier classification status summaries. Together, our comprehensive analysis of this fauna suggests that the greater Mindanao faunal region possesses distinct subcenters of amphibian and reptile species diversity, and that until this area is revisited and its fauna and actually studied, with on-the-ground field work including targeted surveys of species distributions coupled to the study their natural history, our understanding of the diversity and conservation status of southern Philippine herpetological fauna will remain incomplete. Nevertheless, the northeast Mindanao geographical area (Caraga Region) appears to have the highest herpetological species diversity (at least 126 species) of any comparably-sized Philippine faunal subregion

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & NemĂ©sio 2007; Donegan 2008, 2009; NemĂ©sio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    Data from: Evidence for repeated acquisition and loss of complex body form characters in an insular clade of Southeast Asian semi-fossorial skinks

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    Evolutionary simplification, or loss of complex characters, is a major theme in studies of body form evolution. The apparently infrequent evolutionary reacquisition of complex characters has led to the assertion (Dollo’s Law) that once lost, complex characters may be impossible to re-evolve, at least via the exact same evolutionary process. Here we provide one of the most comprehensive, fine-scale analyses of squamate body-form evolution to date, introducing a new model system of closely related, morphologically variable, lizards. Our phylogenetic results support independent instances of complete limb loss as well as multiple instances of digit and external ear opening loss and re-acquisition. Even more striking, we find strong statistical support for the re-acquisition of a pentadactyl body form from a digit-reduced ancestor. Our study reveals that species of the genus Brachymeles exemplify regions of morphospace (body plans) previously undocumented in squamates. Our findings have broad, general implications for body form evolution in burrowing vertebrates: whatever constraints have shaped trends in morphological evolution among other squamate groups (excluding Bipes) have been lost in this one exemplary clade. The results of our study join a nascent body of literature showing strong statistical support for complex character loss, followed by evolutionary re-acquisition of complex structures associated with a generalized pentadactyl body form

    Siler and Brown Morphometric Data

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    This is an excel file with morphological data used for this study. The file provides both the raw data as well as the natural log-transformed data. Log-transformed data columns are highlighted in blue. Each row corresponds to a species or lineage from the study. Column 1 provides the species/lineage name, with multiple lineages for a single species having locality identifiers

    Multiple Alignment

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    Nexus file containing multiple alignment of mitochondrial DNA sequences used in phylogenetic analyses

    Data from: An adaptive radiation of frogs in a Southeast Asian island archipelago

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    Living amphibians exhibit a diversity of ecologies, life histories, and species-rich lineages that offers opportunities for studies of adaptive radiation. We characterize a diverse clade of frogs (Kaloula, Microhylidae) in the Philippine island archipelago as an example of an adaptive radiation into three primary habitat specialists or ecotypes. We use a novel phylogenetic estimate for this clade to evaluate the tempo of lineage accumulation and morphological diversification. Because species-level phylogenetic estimates for Philippine Kaloula are lacking, we employ dense population sampling to determine the appropriate evolutionary lineages for diversification analyses. We explicitly take phylogenetic uncertainty into account when calculating diversification and disparification statistics and fitting models of diversification. Following dispersal to the Philippines from Southeast Asia, Kaloula radiated rapidly into several well-supported clades. Morphological variation within Kaloula is partly explained by ecotype and accumulated at high levels during this radiation, including within ecotypes. We pinpoint an axis of morphospace related directly to climbing and digging behaviors and find patterns of phenotypic evolution suggestive of ecological opportunity with partitioning into distinct habitat specialists. We conclude by discussing the components of phenotypic diversity that are likely important in amphibian adaptive radiations
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