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Mathieu Denoël - One of the best experts on this subject based on the ideXlab platform.
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provenance of ichthyosaura alpestris caudata salamandridae introductions to france and new zealand assessed by mitochondrial dna analysis
Herpetological Journal, 2016Co-Authors: J W Arntzen, Mathieu Denoël, Tania M King, Inigo Martinezsolano, Graham P WallisAbstract:The last century has seen an unparalleled movement of species around the planet as a direct result of human activity, which has been a major contributor to the biodiversity crisis. Amphibians represent a particularly vulnerable group, exacerbated by the devastating effects of chytrid fungi. We report the malicious translocation and establishment of the Alpine Newt (Ichthyosaura alpestris) to its virtual antipode in North Island of New Zealand. We use network analysis of mitochondrial DNA haplotypes to identify the original source population as I. a. apuana from Tuscany, Italy. Additionally, a population in southern France, presumed to be introduced, is identified as I. a. alpestris from western Europe. However, the presence of two differentiated haplotypes suggests a mixed origin. This type of analysis is made possible by the recent availability of a phylogenetic analysis of the species throughout its natural range. We discuss the particulars of both introductions.
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The native Alpine Newt (Ichthyosaura alpestris) and the introduced goldfish (Carassius auratus).
2013Co-Authors: Laurane Winandy, Mathieu DenoëlAbstract:The native Alpine Newt (Ichthyosaura alpestris) and the introduced goldfish (Carassius auratus).
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Displaying in the dark: light-dependent alternative mating tactics in the Alpine Newt
Behavioral Ecology and Sociobiology, 2010Co-Authors: Mathieu Denoël, Joffrey DoellenAbstract:Environment plays a major role for determining the kind of courtship behaviours or alternative mating tactics employed, but the effect of physical variables on fitness has received little attention. The Alpine Newt courts during both day and night times and exhibits a complex suite of behaviours involving olfactory, visual and tactile cues. Displaying in both dark and light conditions may increase the number of mating opportunities and alleviate predation risk, but the frequency and efficacy of the various tactics deployed may vary across light conditions, leading males to vary their use of these tactics across different light regimes. To test this hypothesis, we video-recorded sexual encounters at two light intensities in a controlled experimental design. When courting in the dark, males used comparatively more olfactory rather than visual displays. They also relied more on positive feedback from the female before releasing a spermatophore for her to pick up. The particular mix of tactics used under each light condition is likely to be adaptive because in the dark (1) visual communication is hampered, making olfactory displays possibly more effective and (2) males depositing spermatophores are more likely to lose fertilizations to competitors. Mating in light and dark conditions has similar reproductive payoffs, which shows that displaying in the dark is not detrimental and may even be advantageous if predation risk is reduced at night. These results confirm the importance of taking into account physical variables to understand the evolution of sexual communication in animals.
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Effect of water temperature on the courtship behavior of the Alpine Newt Triturus alpestris
Behavioral Ecology and Sociobiology, 2005Co-Authors: Mathieu Denoël, Maryève Mathieu, Pascal PoncinAbstract:Temperature is expected to have an effect on the behavioral patterns of all organisms, especially ectotherms. However, although several studies focused on the effect of temperature on acoustic displays in both insects and anurans, almost nothing is known about how environmental temperature may affect ectotherm visual courtship displays and sexual performance. The purpose of this study was to determine the effect of environmental temperature on the sexual behavior of Alpine Newts ( Triturus alpestris ). We subjected T. alpestris to two different temperatures in controlled laboratory conditions. Temperature had a major effect on both male and female behaviors: at low temperature, the frequencies of several displays, including tail-raising during sperm deposition, are lowered. This variation is caused indirectly by temperature because it is due to female responsiveness, which is temperature-dependent. However, the fanning movement of the male’s tail during its main courtship display is independent of female behavior: at lower temperatures, the tail beats at a lower rate, but for a longer time. The similar reproductive success (i.e. sperm transfer) at the two temperature ranges indicates that breeding in cold water is not costly but instead allows males and females to mate early in the season. This is particularly adaptive because, in many habitats, the reproductive period is shortened by drying or freezing conditions, which may impair survival of branchiate offspring. This study also demonstrates the necessity of considering environmental parameters when modeling optimality and characteristics of ectotherm behaviors.
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COURTSHIP BEHAVIOR IN THE Alpine Newt TRITURUS ALPESTRIS AT TWO DIFFERENT DENSITIES OF MALES
Herpetologica, 2005Co-Authors: Mathieu Denoël, Marie-pierre Hector, Pascal PoncinAbstract:The aim of this laboratory experiment was to examine courtship behavior and reproductive success under two different perceived male densities in the Alpine Newt (Triturus alpestris). Male behavioral patterns were similar at unbiased and male-biased operational sex ratios (OSR). Although the exhibition of luring behaviors is risky in the presence of other males, no difference in the frequencies of displays was found at the two male densities. Similarly, the responsiveness of females towards males and the success rate of the encounters (i.e., spermatophore transfer) were not explained by the OSR. Our results show that courting Alpine Newts do not change their courtship patterns when other males are present and do not interact directly. However they are not necessarily opposed to those of previous experiments showing sexual interference and female aversion in male-biased OSR with possibility of interactions. These observations suggest that the evolution of courtship behavior may not be driven by the risk of ...
Pierre Joly - One of the best experts on this subject based on the ideXlab platform.
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A 40-year-old divided highway does not prevent gene flow in the Alpine Newt Ichthyosaura alpestris
Conservation Genetics, 2013Co-Authors: Jérôme G. Prunier, Bernard Kaufmann, François Pompanon, Jean-paul Léna, Serge Fenet, Pierre JolyAbstract:Roads are of major concern in conservation biology, as they are known to restrict animal movements through landscape fragmentation, and may therefore impact genetic patterns in native terrestrial organisms. We assessed the effect of two large-scale transportation infrastructures (LTIs), a 40-year-old highway and a 30 year-old high-speed railway, on the spatial genetic structure of the Alpine Newt Ichthyosaura alpestris, a highly nomadic amphibian. Genetic data were gathered following a targeted individual-based sampling scheme and analysed using both overlay and correlative methods. While simulations suggested that the highway may be old enough for a significant barrier effect to be detected, LTIs were never detected as barriers to gene flow: inferred genetic boundaries rather coincided with transition zones between major landscape entities. Furthermore, spatial principal component analysis, a method designed to reveal cryptic genetic spatial patterns in high gene flow species, counter-intuitively suggested that the highway may act as a potential dispersal corridor in low-quality habitats, thus challenging traditional hypotheses on road impacts in amphibians. Our study showed that considering local interactions between species, infrastructures and landscape-specific characteristics is essential for better understanding the potential impacts of roads on movement patterns in terrestrial organisms.
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RESEARCH ARTICLE A 40-year-old divided highway does not prevent gene flow in the Alpine Newt Ichthyosaura alpestris
2013Co-Authors: Serge Fenet, Pierre JolyAbstract:Abstract Roads are of major concern in conservation biology, as they are known to restrict animal movements through landscape fragmentation, and may therefore impact genetic patterns in native terrestrial organisms. We assessed the effect of two large-scale transportation infrastructures (LTIs), a 40-year-old highway and a 30 year-old high-speed railway, on the spatial genetic structure of the Alpine Newt Ichthyosaura alpestris, a highly nomadic amphibian. Genetic data were gathered following a targeted individual-based sampling scheme and analysed using both overlay and correlative methods. While simulations suggested that the highway may be old enough for a significant barrier effect to be detected, LTIs were never detected as barriers to gene flow: inferred genetic boundaries rather coincided with transition zones between major landscape entities. Further-more, spatial principal component analysis, a method designed to reveal cryptic genetic spatial patterns in high gene flow species, counter-intuitively suggested that the highway may act as a potential dispersal corridor in low-quality habitats, thus challenging traditional hypotheses on road impacts in amphibians. Our study showed that con-sidering local interactions between species, infrastructures and landscape-specific characteristics is essential for better understanding the potential impacts of roads on movement patterns in terrestrial organisms
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Skin swabbing as a new efficient DNA sampling technique in amphibians, and 14 new microsatellite markers in the Alpine Newt (Ichthyosaura alpestris).
Molecular ecology resources, 2012Co-Authors: Jérôme G. Prunier, Bernard Kaufmann, Odile Grolet, Damien Picard, François Pompanon, Pierre JolyAbstract:This study introduces a novel DNA sampling method in amphibians using skin swabs. We assessed the relevancy of skin swabs relevancy for genetic studies by amplifying a set of 17 microsatellite markers in the Alpine Newt Ichthyosaura alpestris, including 14 new polymorphic loci, and a set of 11 microsatellite markers in Hyla arborea, from DNA collected with buccal swabs (the standard swab method), dorsal skin swabs and ventral skin swabs. We tested for quality and quantity of collected DNA with each method by comparing electrophoresis migration patterns. The consistency between genotypes obtained from skin swabs and buccal swabs was assessed. Dorsal swabs performed better than ventral swabs in both species, possibly due to differences in skin structure. Skin swabbing proved to be a useful alternative to buccal swabbing for small or vulnerable animals: by drastically limiting handling, this method may improve the trade-off between the scientific value of collected data, individual welfare and species conservation. In addition, the 14 new polymorphic microsatellites for the Alpine Newt will increase the power of genetic studies in this species. In four populations from France (n = 19–25), the number of alleles per locus varied from 2 to 16 and expected heterozygosities ranged from 0.04 to 0.91. Presence of null alleles was detected in two markers and two pairs displayed gametic disequilibrium. No locus appeared to be sex-linked.
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Trophic specialisations in alternative heterochronic morphs
Naturwissenschaften, 2004Co-Authors: Mathieu Denoël, Robert Schabetsberger, Pierre JolyAbstract:Polymorphisms are suspected of reducing competition among conspecifics in heterogeneous environments by allowing differential resource use. However the adaptive significance of alternative morphs has been poorly documented. The aim of this study is to determine food partitioning of two heterochronic morphs of the Alpine Newt, Triturus alpestris , in mountain lakes. The morphs differ in the functional morphology of their feeding apparatus. Only paedomorphs are able to expel water during prey suction behind the mouth through gill slits. We observed a substantial trophic differentiation between morphs in all lakes. Paedomorphs preyed mainly on plankton, whereas metamorphs foraged on terrestrial invertebrates that fell upon the water surface. This resource partitioning may facilitate the coexistence of the alternative morphs in lakes devoid of vertebrate competitors. Food diversity may thus favour the evolutionary maintenance of facultative polymorphism in natural populations.
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impacts of tattooing and pit tagging on survival and fecundity in the Alpine Newt triturus alpestris
Herpetologica, 2002Co-Authors: Nadege Perret, Pierre JolyAbstract:We investigated the impacts of PIT-tagging and tattooing on survival, condition, and egg laying in Alpine Newts (Triturus alpestris) by both field and laboratory experiments. A laboratory experiment made it possible to compare impacts of each marking technique with control groups of unmarked Newts. This experiment consisted of a 3 × 3 factorial plan (population, replication, and marking) using 90 individuals of each sex. Neither survival nor body condition were affected by marking. No variation was detected between marking treatments. However, marked females laid significantly more eggs than control females. We assume that such higher reproductive outputs are responses to the stress induced by skin injury by both marking techniques, but this hypothesis remains to be tested. The field experiment consisted of monitoring a Newt population in a pond where individuals (n = 121) were marked by either marking technique. No difference in survival or in body condition was detected between marking treatments. Eithe...
Denoël Mathieu - One of the best experts on this subject based on the ideXlab platform.
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Morphological integration and alternative life history strategies: a case study in a facultatively paedomorphic Newt
2017Co-Authors: Tomašević Natasa, Denoël Mathieu, Cvijanović Milena, Ivanović AnaAbstract:Tetrapod limbs are serially homologous structures that represent a particularly interesting model for studies on morphological integration, i.e. the tendency of developmental systems to produce correlated variation. In Newts, limbs develop at an early larval stage and grow continuously, including after the habitat transition from water to land following metamorphosis. However, aquatic and terrestrial environments impose different constraints and locomotor modes that could affect patterns of morphological integration and evolvability. We hypothesize that this would be the case for alternative heterochronic morphs in Newts, i.e. aquatic paedomorphs that keep gills at the adult stage and adult metamorphs that are able to disperse on land. To this end, we analysed patterns and strengths of correlations between homologous skeletal elements of the fore- and hindlimbs as well as among skeletal elements within limbs in both phenotypes in the Alpine Newt, Ichthyosaura alpestris. Our results showed that metamorphs and paedomorphs had similar, general patterns of limb integration. Partial correlations between homologous limb elements and within limb elements were higher in paedomorphs when compared to metamorphs. Decrease in partial correlation between homologous limb elements in metamorphs is accompanied with a higher evolvability of the terrestrial morph. All these results indicate that environmental demands shaped the patterns of morphological integration of Alpine Newt limbs and that the observed diversity in correlation structure could be related to a qualitative difference in the modes of locomotion between the morphs.Peer reviewe
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Morphological Integration and Alternative Life History Strategies: A Case Study in a Facultatively Paedomorphic Newt
2017Co-Authors: Tomašević Kolarov Nataša, Denoël Mathieu, Cvijanović Milena, Ivanović AnaAbstract:Tetrapod limbs are serially homologous structures that represent a particularly interesting model for studies on morphological integration, i.e. the tendency of developmental systems to produce correlated variation. In Newts, limbs develop at an early larval stage and grow continuously, including after the habitat transition from water to land following metamorphosis. However, aquatic and terrestrial environments impose different constraints and locomotor modes that could affect patterns of morphological integration and evolvability. We hypothesize that this would be the case for alternative heterochronic morphs in Newts, i.e. aquatic paedomorphs that keep gills at the adult stage and adult metamorphs that are able to disperse on land. To this end, we analyzed patterns and strengths of correlations between homologous skeletal elements of the fore- and hindlimbs as well as among skeletal elements within limbs in both phenotypes in the Alpine Newt, Ichthyosaura alpestris. Our results showed that metamorphs and paedomorphs had similar, general patterns of limb integration. Partial correlations between homologous limb elements and within limb elements were higher in paedomorphs when compared to metamorphs. A decrease in partial correlation between homologous limb elements in metamorphs is accompanied with a higher evolvability of the terrestrial morph. All these results indicate that environmental demands shaped the patterns of morphological integration of Alpine Newt limbs and that the observed diversity in correlation structure could be related to a qualitative difference in the modes of locomotion between the morphs
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Provenance of Ichthyosaura alpestris (Caudata: Salamandridae) introductions to France and New Zealand assessed by mitochondrial DNA analysis
2016Co-Authors: Arntzen, Jan W., Denoël Mathieu, King, Tania M., Martínez-solano Iñigo, Wallis, Graham P.Abstract:The last century has seen an unparalleled movement of species around the planet as a direct result of human activity, which has been a major contributor to the biodiversity crisis. Amphibians represent a particularly vulnerable group, exacerbated by the devastating effects of chytrid fungi. We report the malicious translocation and establishment of the Alpine Newt (Ichthyosaura alpestris) to its virtual antipode in North Island of New Zealand. We use network analysis of mitochondrial DNA haplotypes to identify the original source population as I. a. apuana from Tuscany, Italy. Additionally, a population in southern France, presumed to be introduced, is identified as I. a. alpestris from western Europe. However, the presence of two differentiated haplotypes suggests a mixed origin. This type of analysis is made possible by the recent availability of a phylogenetic analysis of the species throughout its natural range. We discuss the particulars of both introductions.Peer reviewe
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Provenance of Ichthyosaura alpestris (Caudata: Salamandridae) introductions to France and New Zealand assessed by mitochondrial DNA analysis
'British Herpetological Society', 2016Co-Authors: Arntzen, Jan W., Denoël Mathieu, King, Tania M., Martínez-solano Iñigo, Wallis, Graham P.Abstract:peer reviewedaudience: researcher, professional, studentThe last century has seen an unparalleled movement of species around the planet as a direct result of human activity, which has been a major contributor to the biodiversity crisis. Amphibians represent a particularly vulnerable group, exacerbated by the devastating effects of chytrid fungi. We report the malicious translocation and establishment of the Alpine Newt (Ichthyosaura alpestris) to its virtual antipode in North Island of New Zealand. We use network analysis of mitochondrial DNA haplotypes to identify the original source population as I. a. apuana from Tuscany, Italy. Additionally, a population in southern France, presumed to be introduced, is identified as I. a. alpestris from western Europe. However, the presence of two differentiated haplotypes suggests a mixed origin. This type of analysis is made possible by the recent availability of a phylogenetic analysis of the species throughout its natural range. We discuss the particulars of both introductions
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Sex-specific effect of pool desiccation on the movement of Alpine Newts, Mesotriton alpestris (Laurenti, 1768), among breeding sites (Caudata: Salamandridae)
2011Co-Authors: Kopecky Oldrich, Vojar Jiri, Denoël MathieuAbstract:In unpredictable habitats, it is advantageous to amphibians to reduce the risk of weather-induced offspring mortality by utilization of several reproductive patches. In european deciduous forest landscapes, ruts caused by vehicular traffic, typically comprising small vernal or ephemeral pools with variable hydroperiod, are at times used as breeding habitats by some species of amphibians. Previous research shows that in such systems Newts move between ruts within a single reproductive season. The aim was to characterize such movements by means of a capture-mark-recapture study of the Alpine Newt Mesotriton alpestris (laureNti, 1768), during two years differing in water availability, and to detect possible sex-specific differences. Movement between ruts differed between years according to sex. In the year with higher pool drying frequency, more females changed ruts than in the year when stable conditions prevailed. Among the adults that moved between ruts, however, the mean number of aquatic patches visited was higher in males. These results show that the sexes can react differently to environmental correlates and that Alpine Newts are well adapted to utilize networks of temporary pools.Peer reviewe
Jérôme G. Prunier - One of the best experts on this subject based on the ideXlab platform.
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A 40-year-old divided highway does not prevent gene flow in the Alpine Newt Ichthyosaura alpestris
Conservation Genetics, 2013Co-Authors: Jérôme G. Prunier, Bernard Kaufmann, François Pompanon, Jean-paul Léna, Serge Fenet, Pierre JolyAbstract:Roads are of major concern in conservation biology, as they are known to restrict animal movements through landscape fragmentation, and may therefore impact genetic patterns in native terrestrial organisms. We assessed the effect of two large-scale transportation infrastructures (LTIs), a 40-year-old highway and a 30 year-old high-speed railway, on the spatial genetic structure of the Alpine Newt Ichthyosaura alpestris, a highly nomadic amphibian. Genetic data were gathered following a targeted individual-based sampling scheme and analysed using both overlay and correlative methods. While simulations suggested that the highway may be old enough for a significant barrier effect to be detected, LTIs were never detected as barriers to gene flow: inferred genetic boundaries rather coincided with transition zones between major landscape entities. Furthermore, spatial principal component analysis, a method designed to reveal cryptic genetic spatial patterns in high gene flow species, counter-intuitively suggested that the highway may act as a potential dispersal corridor in low-quality habitats, thus challenging traditional hypotheses on road impacts in amphibians. Our study showed that considering local interactions between species, infrastructures and landscape-specific characteristics is essential for better understanding the potential impacts of roads on movement patterns in terrestrial organisms.
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Skin swabbing as a new efficient DNA sampling technique in amphibians, and 14 new microsatellite markers in the Alpine Newt (Ichthyosaura alpestris).
Molecular ecology resources, 2012Co-Authors: Jérôme G. Prunier, Bernard Kaufmann, Odile Grolet, Damien Picard, François Pompanon, Pierre JolyAbstract:This study introduces a novel DNA sampling method in amphibians using skin swabs. We assessed the relevancy of skin swabs relevancy for genetic studies by amplifying a set of 17 microsatellite markers in the Alpine Newt Ichthyosaura alpestris, including 14 new polymorphic loci, and a set of 11 microsatellite markers in Hyla arborea, from DNA collected with buccal swabs (the standard swab method), dorsal skin swabs and ventral skin swabs. We tested for quality and quantity of collected DNA with each method by comparing electrophoresis migration patterns. The consistency between genotypes obtained from skin swabs and buccal swabs was assessed. Dorsal swabs performed better than ventral swabs in both species, possibly due to differences in skin structure. Skin swabbing proved to be a useful alternative to buccal swabbing for small or vulnerable animals: by drastically limiting handling, this method may improve the trade-off between the scientific value of collected data, individual welfare and species conservation. In addition, the 14 new polymorphic microsatellites for the Alpine Newt will increase the power of genetic studies in this species. In four populations from France (n = 19–25), the number of alleles per locus varied from 2 to 16 and expected heterozygosities ranged from 0.04 to 0.91. Presence of null alleles was detected in two markers and two pairs displayed gametic disequilibrium. No locus appeared to be sex-linked.
Miloš L. Kalezić - One of the best experts on this subject based on the ideXlab platform.
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Morphing of the phylogeographic lineages of the Balkan Alpine Newts (Ichthyosaura alpestris, Caudata, Salamandridae): in situ morphological diversification.
Comptes rendus biologies, 2011Co-Authors: Tanja D Vukov, Konstantinos Sotiropoulos, Miloš L. Kalezić, Georg DžukićAbstract:Numerous Alpine Newt (Ichthyosaura alpestris) populations from the Balkans, representing all the previously established phylogeographic lineages, were studied for variations in various morphological characteristics (body size and shape, skull qualitative traits and number of trunk vertebrae). Here, we present a decoupling of morphological and mtDNA phylogeographic substructuring in the Alpine Newt on the Balkan Peninsula. In sharp contrast to other European Newts (Triturus spp., Lissotriton spp.), the vast majority of morphological variation in the Alpine Newt is concentrated at the population level indicating an in situ morphological diversification. We found that the rate of morphological change is similar to the rate of mtDNA change. We hypothesize that the Alpine Newts are characterized by non-adaptive morphological evolution.
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Testing the hypothesis of morphological integration on a skull of a vertebrate with a biphasic life cycle: a case study of the Alpine Newt.
Journal of experimental zoology. Part B Molecular and developmental evolution, 2010Co-Authors: Ana Ivanović, Miloš L. KalezićAbstract:In this article, we explore the possible influences of the developmental and functional relationships between skeletal elements on the pattern of morphological integration in the adult skull of the Alpine Newt. Like many tailed amphibians, the Alpine Newt has a biphasic life cycle, which implies the possibility that two distinct sets of constraints on development and function of the cranial skeleton may act at different times. We study how trait covariation, resulting from processes early in development, affects patterns of covariation at the adult stage. We test whether the observed patterns of integration are consistent with those predicted from three a priori hypothesized sources of integration: developmental timing, hormonally mediated growth/remodeling during metamorphosis, and developmental and functional relationships. The analyses of the covariation among the landmarks in the dorsal and ventral Alpine Newt craniums yield somewhat contrasting results. Our results do not indicate a clear correspondence between the observed variations in the skull shape and any of the three proposed hypotheses. No traceable reflection of hypothesized developmental relationships in the pattern of morphological integration/modularity in the adult skull indicate that covariation structure is continually restructured by overlaying variation introduced through developmental and environmental factors at different stages of development. This finding supports the recently elaborated palimpsest view of morphological integration. Also, our results indicate that the allometry-free shape data have an even higher level of morphological integration than the data that contain the allometric component of the shape variation.
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Alternative life‐history pathways: paedomorphosis and adult fitness in European Newts (Triturus vulgaris and T. alpestris)
Journal of Zoological Systematics and Evolutionary Research, 2009Co-Authors: Miloš L. Kalezić, Dragana D Cvetkovic, Ana Djorović, Georg DžukićAbstract:Paedomorphs and metamorphs of the smooth Newt (Triturus vulgaris) and Alpine Newt (Triturus alpestris) were compared with respect to body size, age structure, age at sexual maturity, survivorship, and female and male fecundity. Paedomorphs were significantly smaller than metamorphs, except for the Alpine Newt males. Non-significant differences between morphs in both species in terms of the life span, age of sexual maturity, survival rates and male fecundity were found. The relationships concerning female-fecundity parameters were not so straightforward. The total number of oocytes was significantly higher in smooth-Newt paedomorphs, while in the Alpine Newt the difference was insignificant. When ovary mass was compared, significant differences appeared only in the Alpine Newt, in favour of metamorphic females. Oviductal egg size was similar in both morphs of T. vulgaris. The maintenance of both life-history strategies in the species studied is discussed in the light of these findings.
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Phylogeny and biogeography of the Alpine Newt Mesotriton alpestris (Salamandridae, Caudata), inferred from mtDNA sequences.
Molecular phylogenetics and evolution, 2007Co-Authors: Konstantinos Sotiropoulos, Miloš L. Kalezić, Anastasios Legakis, Georg Džukić, Karolos Eleftherakos, Rosa-maria PolymeniAbstract:In this paper, we performed phylogenetic analyses of Mesotriton alpestris populations from the entire range of species distribution, using fragments of two mtDNA genes, cytochrome b (309 bp) and 16S rRNA (∼500 bp). Sequence diversity patterns and phylogenetic analyses reveal the existence of a relict lineage (Clade A) of late Miocene origin, comprising populations from south-eastern Serbia. This lineage is proposed to be ancestor to a western and an eastern lineage, which diverged during the middle Pliocene. The western lineage is further divided in two clades (Clades B, C) of middle Pliocene origin that represent populations from Italy (B) and populations from central Europe and Iberia (C). Further subdivision, dated back to the middle-late Pliocene, was found within the eastern lineage, representing southern (Clade D) and central-northern (Clade E) Balkan populations, respectively. Extensive sequence divergence, implying greater isolation in multiple refugia, is found within eastern clades, while the western clades seem to have been involved in the colonization of central, western and north-eastern Europe from a hypothetical refugium in central Europe. The extent of divergence does not support the current taxonomy indicating cryptic speciation in the Balkans, while paedomorphic lineages were found to have been evolved during early-middle Pleistocene probably as a response to the ongoing dramatic climatic oscillations.
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Paedogenesis in european Newts (Triturus: salamandridae): cranial morphology during ontogeny.
Journal of morphology, 2000Co-Authors: Ana Djorović, Miloš L. KalezićAbstract:A cross-sectional analysis using different ontogenetic stages (larvae, juveniles, paedotypic, and metamorphic adults) of the smooth Newt, Triturus vulgaris, and the Alpine Newt, T.alpestris, revealed a broad spectrum of perennibranchiation influences on cranial ontogeny in European Newts, more pronounced than previously thought. These influences included marked variation in ossification levels, pronounced morphometric variability of many cranial elements, and considerable skull shape changes in the transition from larvae to the adult stage. In comparison with metamorphosed individuals, paedotypic Newts had a higher level of variability in both individual cranial traits and cranial shape changes. Sexual size difference of the skull traits was mostly negligible, especially in comparison to the influence of paedogenesis. The main changes in cranial shape of the European Newts occurred during metamorphosis. Cranial morphological organization in the majority of examined paedotypes corresponds to cranial organization at late larval stages prior to metamorphosis or at the onset of metamorphosis.