For a long time, snakes were presented as a textbook example of a group with gradual differentiation of homologous ZZ/ZW sex chromosomes. However, recent advances revealed that the ZZ/ZW sex chromosomes characterize only caenophidian snakes and certain species of boas and pythons have nonhomologous XX/XY sex chromosomes. We used genome coverage analysis in four non-caenophidian species to identify their sex chromosomes, and we examined the homology of sex chromosomes across phylogenetically informative snake lineages.
View Article and Find Full Text PDFRevealing biodiversity allows the accurate determination of the underlying causes of many biological processes such as speciation and hybridization. These processes contain many complex patterns, especially in areas with high species diversity. As two of the prominent zoogeographic areas, Anatolia and Caucasus are also home to the genus Darevskia, which has a complex morphological structure and parthenogenetic speciation.
View Article and Find Full Text PDFWithin the Balkan Peninsula, topographic and climatic agents have promoted biodiversity and shaped the speciation history of many ectotherms. Here, we targeted an iconic European reptile, the nose-horned viper species-complex (Vipera ammodytes), and explored its spatial and temporal evolution. We (i) utilized genome-wide single nucleotide polymorphisms to infer genetic structure and build a time-calibrated species-tree, and (ii) applied species distribution modelling with niche-divergence tests among major phylogenomic clades.
View Article and Find Full Text PDFEffective biodiversity conservation planning starts with genetic characterization within and among focal populations, in order to understand the likely impact of threats for ensuring the long-term viability of a species. The Wonder Gecko, Teratoscincus keyserlingii, is one of nine members of the genus. This species is distributed in Iran, Afghanistan, and Pakistan, with a small isolated population in the United Arab Emirates (UAE), where it is classified nationally as Critically Endangered.
View Article and Find Full Text PDFScolecophidia (worm snakes) are a vertebrate group with high ecomorphological conservatism due to their burrowing lifestyle. The Eurasian or Greek blindsnake Xerotyphlops vermicularis is their only European representative, a species-complex with an old diversification history. However, its systematics and taxonomy has remained untouched.
View Article and Find Full Text PDFMitochondrial DNA B Resour
October 2018
Background: Debated aspects in speciation research concern the amount of gene flow between incipient species under secondary contact and the modes by which post-zygotic isolation accumulates. Secondary contact zones of allopatric lineages, involving varying levels of divergence, provide natural settings for comparative studies, for which the Aegean (Eastern Mediterranean) geography offers unique scenarios. In Palearctic green toads (Bufo viridis subgroup or Bufotes), Plio-Pleistocene (~ 2.
View Article and Find Full Text PDFThe Aegean region, located in the Eastern Mediterranean, is an area of rich biodiversity and endemism. Its position, geographical configuration and complex geological history have shaped the diversification history of many animal taxa. Mygalomorph spiders have drawn the attention of researchers, as excellent model systems for phylogeographical investigations.
View Article and Find Full Text PDFThe study of mitochondrial and nuclear DNA sequences reveals that the polytypic Blanus strauchi is a species complex including three well-defined allopatric clades, one of which consists of two sub-clades. Only the two sub-clades of the Western clade are morphologically diagnosable in the field, whereas obvious characters to distinguish the Central and the Eastern clades are lacking. However, all four clades show significant statistical differentiation on meristic traits, as well as in morphometric characters of the head when compared by means of the geometric morphometrics.
View Article and Find Full Text PDFThe majority of the family Typhlopidae occurs in the Neotropic, Australasian, Indo-Malayan and Afrotropic ecoregions. They show a restricted distribution in the western Palearctic, where they include few native species, i.e.
View Article and Find Full Text PDFTyphlops vermicularis is the only extant scolecophidian representative occurring in Europe. Its main distribution area, the eastern Mediterranean, has a complicated geological and climatic history that has left an imprint on the phylogenies and biogeography of many taxa, especially amphibians and reptiles. Since reptiles are sensitive indicators of palaeogeographical and palaeoclimatic events, we investigated the intraspecific genealogy of T.
View Article and Find Full Text PDFWe analyze geographic genetic variation in C. ocellatus to evaluate the influences of major climatic, paleogeographic and anthropogenic factors in its biogeographic history. Ninety four specimens from 61 populations were collected across all of its geographical range and analyzed based on partial mitochondrial sequences (cyt b, 12S, and ND1).
View Article and Find Full Text PDF