Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world’s vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall pattern conceals the impact of conservation successes, and we show that the rate of deterioration would have been at least one-fifth again as much in the absence of these. Nonetheless, current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups: agricultural expansion, logging, overexploitation, and invasive alien species
AbstractThe designation of taxonomic units has important implications for the understanding and conservation of biodiversity. Eurasian vipers are a monophyletic group of viperid snakes (Serpentes, Viperinae), currently comprising four genera (Daboia, Macrovipera, Montivipera and Vipera) and up to 40 species. Taxonomic units have been described using a wide variety of methods and criteria, and consequently, considerable controversy still surrounds the validity of some currently listed species. In order to promote a consensus- and evidence-based taxonomy of Eurasian vipers, we analysed published mitochondrial and nuclear DNA sequences for this group to reconstruct phylogenetic relationships among currently recognized viper species. We also compiled information on external morphology to assess their morphological distinctiveness. Phylogenetic inference based on mtDNA sequences shows contrasting levels of divergence across genera and species and identifies several instances of non-monophyly in described species. Nuclear DNA sequences show extremely low levels of genetic variation, with a widespread pattern of allele sharing among distant species, and even among genera. Revision of morphological data shows that most species designations rely on scalation traits that overlap extensively among species of the same genus. Based on our combined assessment, we recognize 15 taxa as valid species, three taxa which likely represent species complexes, 17 taxa of doubtful validity as species, and five taxa for which species status is maintained but further research is highly recommended to assess taxonomic arrangements. We stress the need to implement integrative taxonomic approaches for the recognition of evidence-based taxonomic units in Eurasian vipers.
This paper continues the publication of new data obtained during field studies in remote and poorly studied regions of Laos in 2015–2018. It provides descriptions of two new species (Bulbophyllum brachyscapum Aver. and Sunipia saccata Aver.), emended descriptions of two previously published but insufficiently known species (Cleisostoma verrucosum Aver., Oberonia vesiculifera Aver.) and reports of eight species newly recorded in the flora of Laos (Biermannia calcarata Aver., Bulbophyllum farreri (W. W. Sm.) Seidenf., Didymoplexiella trichechus (J. J. Sm.) Garay, Eria eriopsidobulbon C. S. P. Parish et Rchb. fil., Habenaria ciliolaris Kraenzl., Liparis caudata Aver. et K. S. Nguyen, Odontochilus umbrosus (Aver.) Ormerod, and Porpax ustulata (C. S. P. Parish et Rchb. fil.) Rolfe). Appropriate citations of regional literature, colour illustrations, data on types and distribution, descriptions, etymology, as well as notes on taxonomy and related species are provided for the studied species.
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