The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jean Clobert - One of the best experts on this subject based on the ideXlab platform.
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the importance of habitat resistance for movement decisions in the common lizard lacerta vivipara
2012Co-Authors: Felix Zajitschek, Susanne R K Zajitschek, Jean ClobertAbstract:Background Movement behaviour can be influenced by a multitude of biotic and abiotic factors. Here, we investigate the speed of movement in relation to environmental and individual phenotypic properties in subadult common lizards (Lacerta vivipara). We aim to disentangle the importance of substrate, cover, humidity, basking opportunity and individual phenotype on moving tendencies in 12 treatment combinations, at which each lizard was tested.
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phenotypic plasticity of growth and survival in the common lizard lacerta vivipara
1996Co-Authors: Gabriele Sorci, Jean Clobert, Sophie BelichonAbstract:1. In this study we investigated sources of variation in growth rate and survival in the common lizard Lacerta vivipara. 2. We conducted two experiments to identify factors that explain the pattern of geographic variation of life-history traits in this species. In the first experiment, we raised hatchlings from two French populations of L. vivipara, located at low (150 m) and high (1400m) altitudes, under identical laboratory conditions. The hatchlings grew at the same rate when experiencing the same environmental conditions irrespective of their origin. This finding suggests that the observed differences in growth rate between these two populations of L. vivipara are driven by environmental factors (e.g. thermal environment) rather than genetic divergence. Although we did not find any genetic difference between populations, we found some evidence of within-population variation in growth rate. 3. In a second experiment, we raised hatchlings from the high altitude population in outdoor enclosures located at low and high altitudes. The site where hatchlings were raised had a large impact on both growth and survival. Lizards located in the low altitude site grew faster and had a higher mortality rate than lizards located in the high altitude site. These findings are consistent with the observed differences in growth and survival between the natural populations inhabiting the two localities. 4. In spite of the low statistical power of the models used to detect the family x environment interactions, we found a marginally significant interaction for survival (P = 0.054), which suggests that phenotypic plasticity of this trait may have some degree of genetic variance. 5. Finally, we did not find any evidence for a genetic correlation between growth and survival in the high altitude population. This suggests that the observed phenotypic trade-off between the two traits may arise from environmental constraints (e.g. more active lizards have higher growth rates but also have higher risks of predation). 6. Overall, our findings emphasize that environmental factors may play a major role in shaping patterns of life-history association in L. vivipara, and in explaining geographic variation of life histories.
Larissa A Kupriyanova - One of the best experts on this subject based on the ideXlab platform.
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distribution of the common or viviparous lizard zootoca vivipara lichtenstein 1823 squamata lacertidae in central europe and re colonization of the baltic sea basin new karyological evidence
2017Co-Authors: Larissa A Kupriyanova, Tom Kirschey, Wolfgang BöhmeAbstract:The widely distributed viviparous lizard Zootoca vivipara (Lichtenstein 1823) revealed considerable differences in physiology, karyology, molecular genetics, and natural history. Based on chromosomal and mtDNA data several distinct karyotypic forms and haplotypes have been described from Central Europe. In an attempt to further clarify the geographic distribution of two karyologically different forms within the viviparous, nominotypic Z. v. vivipara , we studied the karyotypes of specimens from two NE German localities in West Pomerania (Baltic Sea) and Brandenburg, respectively, and also of those from Mt. Kopaonik in Serbia. All individuals karyotyped represented the western form of Z. v. vivipara that differs from other chromosomal forms of Central Europe in several karyotype characters. It inhabits the south coast of the Baltic Sea between the German harbor city of Kiel in the west and the Russian harbor city of Kaliningrad in the east. Recently, the eastern, so-called Russian form of Z. v. vivipara was recorded also in the Kaliningrad exclave, in Belarus near the border Belarus-Poland and even in easternmost Poland, then further eastwards along the Baltic Sea coast including Finland. Our data show that easternmost German populations still belong to the western form, as it is also the case in the SE European Serbian locality sampled. Together with previous data sets, our results document chromosomal uniformity within the western form of Z. v. vivipara from the Baltic Sea coast to the Carpathian basin and the central Balkans, and earlier hypotheses of the postglacial recolonization of the Baltic Sea basin by Z. vivipara are corroborated.
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distribution of the common or viviparous lizard zootoca vivipara lichtenstein 1823 squamata lacertidae in central europe and re colonization of the baltic sea basin new karyological evidence
2017Co-Authors: Larissa A Kupriyanova, Tom Kirschey, Wolfgang BöhmeAbstract:The widely distributed viviparous lizard Zootoca vivipara (Lichtenstein 1823) revealed considerable differences in physiology, karyology, molecular genetics, and natural history. Based on chromosomal and mtDNA data several distinct karyotypic forms and haplotypes have been described from Central Europe. In an attempt to further clarify the geographic distribution of two karyologically different forms within the viviparous, nominotypic Z. v. vivipara , we studied the karyotypes of specimens from two NE German localities in West Pomerania (Baltic Sea) and Brandenburg, respectively, and also of those from Mt. Kopaonik in Serbia. All individuals karyotyped represented the western form of Z. v. vivipara that differs from other chromosomal forms of Central Europe in several karyotype characters. It inhabits the south coast of the Baltic Sea between the German harbor city of Kiel in the west and the Russian harbor city of Kaliningrad in the east. Recently, the eastern, so-called Russian form of Z. v. vivipara was recorded also in the Kaliningrad exclave, in Belarus near the border Belarus-Poland and even in easternmost Poland, then further eastwards along the Baltic Sea coast including Finland. Our data show that easternmost German populations still belong to the western form, as it is also the case in the SE European Serbian locality sampled. Together with previous data sets, our results document chromosomal uniformity within the western form of Z. v. vivipara from the Baltic Sea coast to the Carpathian basin and the central Balkans, and earlier hypotheses of the postglacial recolonization of the Baltic Sea basin by Z. vivipara are corroborated.
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intraspecific phylogeography of lacerta vivipara and the evolution of viviparity
2001Co-Authors: Yann Surgetgroba, Larissa A Kupriyanova, Benoit Heulin, Claudepierre Guillaume, Roger S Thorpe, Nusa Vogrin, Robert Maslak, Stephano Mazzotti, Marton Venczel, Ioan GhiraAbstract:Abstract The lacertid lizard Lacerta vivipara is one of the few squamate species with two reproductive modes. We present the intraspecific phylogeny obtained from neighbor-joining and maximum-parsimony analyses of the mtDNA cytochrome b sequences for 15 individuals from Slovenian oviparous populations, 34 individuals from western oviparous populations of southern France and northern Spain, 92 specimens from European and Russian viviparous populations, and 3 specimens of the viviparous subspecies L. v. pannonica. The phylogeny indicates that the evolutionary transition from oviparity to viviparity probably occurred once in L. vivipara. The western oviparous group from Spain and southern France is phylogenetically most closely related to the viviparous clade. However, the biarmed W chromosome characterizing the western viviparous populations is an apomorphic character, whereas the uniarmed W chromosome, existing both in the western oviparous populations and in the geographically distant eastern viviparous populations, is a plesiomorphic character. This suggests an eastern origin of viviparity. Various estimates suggest that the oviparous and viviparous clades of L. vivipara split during the Pleistocene. Our results are discussed in the framework of general evolutionary models: the concept of an oviparity–viviparity continuum in squamates, the cold climate model of selection for viviparity in squamates, and the contraction–expansion of ranges in the Pleistocene resulting in allopatric differentiation.
Susanne R K Zajitschek - One of the best experts on this subject based on the ideXlab platform.
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the importance of habitat resistance for movement decisions in the common lizard lacerta vivipara
2012Co-Authors: Felix Zajitschek, Susanne R K Zajitschek, Jean ClobertAbstract:Background Movement behaviour can be influenced by a multitude of biotic and abiotic factors. Here, we investigate the speed of movement in relation to environmental and individual phenotypic properties in subadult common lizards (Lacerta vivipara). We aim to disentangle the importance of substrate, cover, humidity, basking opportunity and individual phenotype on moving tendencies in 12 treatment combinations, at which each lizard was tested.
Luca Cornetti - One of the best experts on this subject based on the ideXlab platform.
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reproductive isolation between oviparous and viviparous lineages of the eurasian common lizard zootoca vivipara in a contact zone
2015Co-Authors: Luca Cornetti, Francesco Belluardo, Samuele Ghielmi, Giovanni Giovine, Gentile Francesco Ficetola, Giorgio Bertorelle, Cristiano Vernesi, Heidi C HauffeAbstract:Contact zones between two evolutionary lineages are often useful for understanding the process of speciation because the observed genetic pattern reflects the history of differentiation. The Eurasian lacertid lizard Zootoca vivipara is a potentially interesting model for studying the role of reproductive mode in the speciation of squamate reptiles because it has both oviparous (Zootoca vivipara carniolica) and viviparous (Zootoca vivipara vivipara) populations that have recently been shown to be genetically distinct. We studied a newly-discovered syntopic area of these two Zootoca subspecies in the central Italian Alps using genetic markers to investigate the level of introgression between them. Patterns of genetic differentiation in a fragment of the mitochondrial DNA cytb gene and a set of nuclear microsatellites show that the speciation process is complete in this area, with no evidence of recent introgression. Phylogenetic and genotypic divergence suggests that the two subspecies have experienced long independent evolutionary histories, during which genetic and phenotypic differences evolved. The possible roles of biogeography, reproductive mode, and cytogenetic differentiation in this speciation process are dis- cussed. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114, 566-573.
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mitochondrial and nuclear dna survey of zootoca vivipara across the eastern italian alps evolutionary relationships historical demography and conservation implications
2014Co-Authors: Luca Cornetti, Benoit Heulin, Giovanni Giovine, Michele Menegon, Cristiano VernesiAbstract:The European common lizard Zootoca vivipara exhibits reproductive bimodality, with populations being either viviparous or oviparous. In the central-eastern Italian Alps oviparous populations (Z. v. carniolica) and viviparous populations (Z. v. vivipara) partly overlap geographically. Studying the evolutionary relationship between these taxa presents an interesting opportunity to gain insight into the evolution of this trait. We aim to: i) test whether Z. v. carniolica, which is endangered, constitutes an ESU (Evolutionary Significant Unity); ii) infer mtDNA divergence time between the Z. v. carniolica clade and all the other Z. vivipara subspecies with the aid of an external calibration point; and iii) describe the phylogeographical and demographic scenarios in the area. To do so we sequenced about 200 individuals for mitochondrial variation; 64 of them were also analysed for three nuclear genes. Furthermore, we analysed the same nuclear markers in 17 individuals from the other oviparous subspecies Z. v. louislantzi and 11 individuals of Z. v. vivipara from widespread geographical origins. The mtDNA and nDNA loci that we examined supported the monophyly of Z. v. carniolica. The mtDNA-based estimate of divergence time between Z. v. carniolica and all the other subspecies indicated a separation at 4.5 Mya (95% CI 6.1–2.6), with about 5% of sequence divergence. Considering that Z. v. carniolica harbours higher genetic diversity, while Z. v. vivipara from central-eastern Alps shows a signature of recent population and spatial expansion, we argue that Z. v. carniolica represents a distinct evolutionary unit, with a presumably long-term evolutionary history of separation. Z. v. carniolica populations, occurring at higher latitudes and altitudes than insofar supposed, live in peat bogs, a seriously threatened habitat: taking into account also its evolutionary distinctness, specific conservation measures should be considered.
Cristiano Vernesi - One of the best experts on this subject based on the ideXlab platform.
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reproductive isolation between oviparous and viviparous lineages of the eurasian common lizard zootoca vivipara in a contact zone
2015Co-Authors: Luca Cornetti, Francesco Belluardo, Samuele Ghielmi, Giovanni Giovine, Gentile Francesco Ficetola, Giorgio Bertorelle, Cristiano Vernesi, Heidi C HauffeAbstract:Contact zones between two evolutionary lineages are often useful for understanding the process of speciation because the observed genetic pattern reflects the history of differentiation. The Eurasian lacertid lizard Zootoca vivipara is a potentially interesting model for studying the role of reproductive mode in the speciation of squamate reptiles because it has both oviparous (Zootoca vivipara carniolica) and viviparous (Zootoca vivipara vivipara) populations that have recently been shown to be genetically distinct. We studied a newly-discovered syntopic area of these two Zootoca subspecies in the central Italian Alps using genetic markers to investigate the level of introgression between them. Patterns of genetic differentiation in a fragment of the mitochondrial DNA cytb gene and a set of nuclear microsatellites show that the speciation process is complete in this area, with no evidence of recent introgression. Phylogenetic and genotypic divergence suggests that the two subspecies have experienced long independent evolutionary histories, during which genetic and phenotypic differences evolved. The possible roles of biogeography, reproductive mode, and cytogenetic differentiation in this speciation process are dis- cussed. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114, 566-573.
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mitochondrial and nuclear dna survey of zootoca vivipara across the eastern italian alps evolutionary relationships historical demography and conservation implications
2014Co-Authors: Luca Cornetti, Benoit Heulin, Giovanni Giovine, Michele Menegon, Cristiano VernesiAbstract:The European common lizard Zootoca vivipara exhibits reproductive bimodality, with populations being either viviparous or oviparous. In the central-eastern Italian Alps oviparous populations (Z. v. carniolica) and viviparous populations (Z. v. vivipara) partly overlap geographically. Studying the evolutionary relationship between these taxa presents an interesting opportunity to gain insight into the evolution of this trait. We aim to: i) test whether Z. v. carniolica, which is endangered, constitutes an ESU (Evolutionary Significant Unity); ii) infer mtDNA divergence time between the Z. v. carniolica clade and all the other Z. vivipara subspecies with the aid of an external calibration point; and iii) describe the phylogeographical and demographic scenarios in the area. To do so we sequenced about 200 individuals for mitochondrial variation; 64 of them were also analysed for three nuclear genes. Furthermore, we analysed the same nuclear markers in 17 individuals from the other oviparous subspecies Z. v. louislantzi and 11 individuals of Z. v. vivipara from widespread geographical origins. The mtDNA and nDNA loci that we examined supported the monophyly of Z. v. carniolica. The mtDNA-based estimate of divergence time between Z. v. carniolica and all the other subspecies indicated a separation at 4.5 Mya (95% CI 6.1–2.6), with about 5% of sequence divergence. Considering that Z. v. carniolica harbours higher genetic diversity, while Z. v. vivipara from central-eastern Alps shows a signature of recent population and spatial expansion, we argue that Z. v. carniolica represents a distinct evolutionary unit, with a presumably long-term evolutionary history of separation. Z. v. carniolica populations, occurring at higher latitudes and altitudes than insofar supposed, live in peat bogs, a seriously threatened habitat: taking into account also its evolutionary distinctness, specific conservation measures should be considered.
