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| Registros recuperados: 15 | |
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| Sket, B.; Arntzen, J.W.. |
| A morphologically distinct cavernicolous salamander Proteus anguinus from southeastern Slovenia (Bela Krajina) is described as P. a. parkelj ssp. n. It differs from P. a. anguinus in a dark pigmentation, fully developed eyes, a skull with broader and shorter bones and fewer teeth, a voluminous jaw musculature that gives the head a bulky appearance, a proportionally longer trunk with a higher number of vertebrae, shorter extremities, and a shorter tail. Most of these traits are considered to be plesiomorphic character states. An allozyme analysis over 40 loci has shown the new dark pigmented taxon to be genetically similar to a white and troglomorphic neighbouring population from Stična (DNei = 0.23). Both populations in turn are genetically dissimilar to a... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Urodela; Proteus; Taxonomy; Morphology; Allozyme analysis; Ecology; Distribution. |
| Ano: 1994 |
URL: http://www.repository.naturalis.nl/record/503865 |
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| Arntzen, J.W.; Jehle, R.; Bardakci, F.; Burke, T.; Wallis, G.P.. |
| Hybridization between divergent lineages often results in reduced hybrid viability. Here we report findings from a series of independent molecular analyses over several seasons on four life stages of F1 hybrids between the newts Triturus cristatus and T. marmoratus. These two species form a bimodal hybrid zone of broad overlap in France, with F1 hybrids making up about 4% of the adult population. We demonstrate strong asymmetry in the direction of the cross, with one class (cristatus-mothered) making up about 90% of F1 hybrids. By analyzing embryos and hatchlings, we show that this asymmetry is not due to prezygotic effects, as both classes of hybrid embryos are present at similar frequencies, implicating differential selection on the two hybrid classes... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Allozyme; Bateson–Dobzhansky–Muller incompatibility; Cytonuclear incompatibility; Hybridization; Microsatellite; MtDNA; Postzygotic isolation asymmetry; Triturus; 42.82. |
| Ano: 2008 |
URL: http://www.repository.naturalis.nl/record/289893 |
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| Arntzen, J.W.; Szymura, J.M.. |
| Toads of the genus Alytes from the Rif mountains in Morocco are electrophoretically very similar to Iberian Alytes obstetricans (DieN = 0.07). Genetic distance estimates across the Straits of Gibraltar do not exceed the values found among European samples. The data point to relatively recent colonization or anthropogenic introduction of the Midwife Toad in Africa. The notion of Pasteur & Bons (1962) that Alytes from the Rif mountains might represent a separate species is not corroborated. |
| Tipo: Article / Letter to the editor |
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| Ano: 1984 |
URL: http://www.repository.naturalis.nl/record/504480 |
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| Arntzen, J.W.; Wallis, Graham P.. |
| Within the newt genus Triturus, the large-bodied species in the T. cristatus (crested newt) superspecies show an unusual degree of variation in relative trunk length as a result of among-taxon variation in interlimb vertebral count. Here we examine the systematic value of this feature as assessed by both exterior measurement (Wolterstorff Index) and direct radiographic count of rib-bearing vertebrae, with particular reference to a number of confounding factors (sex differences, hybridisation, geographic variation, allometry, preservation effects). Using our mtDNA haplotype data, which are largely concordant with geographic distribution of species, we find that direct count of the rib-bearing vertebrae performs more reliably (14% misclassification) than... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Asymmetric hybridisation; Biogeography; Crested newt; Geographic variation; Morphology; MtDNA; Taxonomy; Triturus cristatus. |
| Ano: 1999 |
URL: http://www.repository.naturalis.nl/record/534387 |
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| Arntzen, J.W.; Recuero, E.; Canestrelli, D.; Martínez-Solano, I.. |
| Species delineation remains one of the most challenging tasks in the study of biodiversity, mostly owing to the application of different species concepts, which results in contrasting taxonomic arrangements. This has important practical consequences, since species are basic units in fields like ecology and conservation biology. We here review molecular genetic evidence relevant to the systematics of toads in the Bufo bufo species group (Anura, Bufonidae). Two studies recently published in this journal (Recuero et al., MPE 62: 71–86 and Garci´a-Porta et al., MPE 63: 113–130) addressed this issue but reached opposing conclusions on the taxonomy of the group (four versus two species). In particular, allozyme data in the latter paper were interpreted as... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Bufo bufo; Bufo spinosus; Molecular systematics; Bufo verrucosissimus; Phylogeny; Allozymes; 42.82. |
| Ano: 2013 |
URL: http://www.repository.naturalis.nl/record/470065 |
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| Arntzen, J.W.; García-París, M.. |
| Allozyme variation in 31 to 50 presumptive loci of 12 populations of European midwife toads of the genus Alytes show appreciable genetic divergences (DiNe from 0.29 to 0.72) among four groups. These groups correspond to A. cisternasii Boscá, 1879, A. obstetricans (Laurenti, 1768), A. muletensis (Sanchiz & Adrover, 1979), and a new species from the Betic mountains described here as A. dickhilleni n. sp. Smaller divergences among geographic groups of populations of A. obstetricans (up to DNei = 0.17) support the existence of three geographic units in Europe corresponding to the previously recognized subspecies A. o. obstetricans and A. o. boscai Lataste, 1879, plus a third one described here under the designation of A. o. almogavarii n. ssp. The analysis... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Allozymes; Alytes; Midwife toads; Morphometry; Spain; Taxonomy. |
| Ano: 1995 |
URL: http://www.repository.naturalis.nl/record/504393 |
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| Arntzen, J.W.; McAtear, J.; Recuero, E.; Ziermann, J.M.; Ohler, A.; Alphen, J. van; Martínez-Solano, I.. |
| The Common toad Bufo bufo sensu lato is a widespread, morphologically conserved taxon. Recent studies have uncovered deep genetic differentiation between population groups, highlighting the need to revise the current taxonomy of the group and recognize additional species. Here we investigate patterns of variation in molecular (a mitochondrial DNA restriction enzyme assay and sequence data for two nuclear DNA fragments totalling 979 bp) and 17 morphological variables in Northern France where two of these groups meet (B. bufo sensu stricto and B. spinosus), in order to delineate their contact zone and uncover characters that would allow discrimination of the two taxa. Mitochondrial DNA data show an abrupt transition from areas where B. bufo is present to... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Bufo bufo; Bufo spinosus; Common toad; Contact zone; France; Mitochondrial DNA; Morphometrics; Nuclear DNA; 42.82. |
| Ano: 2013 |
URL: http://www.repository.naturalis.nl/record/475530 |
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| Zajc, I.; Arntzen, J.W.. |
| European newts (genus Triturus) are widely studied, but their phylogeny is not yet unambiguously resolved. Fragments of mitochondrial DNA experiencing different rates of evolution (the ATPase and 12S rRNA genes) were sequenced in order to test a phylogenetic hypothesis derived from biochemical and behavioral data. Well-supported branches of the existing phylogeny gained support in our study. The monophyletic origin of the hypothesized T. boscai — T. italicus clade remained ambiguous, whereas strong support was gained for the sister-taxon relationship of T. vulgaris and T. montandoni. The position of T. vittatus as a sister taxon to the T. marmoratus species group was also supported. The phylogenetic position of T. alpestris could not be clarified. With an... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 12S rRNA; ATPase; Mitochondrial DNA; Newt; Phylogeny; Triturus. |
| Ano: 1999 |
URL: http://www.repository.naturalis.nl/record/534335 |
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| Arntzen, J.W.; García-París, M.. |
| Three competing phylogenetic hypotheses for the genus Alytes (midwife toads) are evaluated. Based on quantitative coding of protein characters the most parsimonious solution shows a sister taxon relationship for Alytes dickhilleni and A. muletensis. The alternatives in which A. obstetricans has its sister group in either A. dickhilleni or A. muletensis lack support. Using calibrations derived from protein evolutionary rates, the vicariant events giving rise to A. obstetricans and the lineage leading to the A. muletensis and A. dickhilleni clade and the subsequent splitting between A. muletensis and A. dickhilleni cannot be placed much earlier than the Miocene-Pliocene boundary. Biogeographical scenarios invoking an earlier time of divergence should be... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Allozymes; Alytes; Biogeography; Midwife toads; Phylogenetics; Spain; Taxonomy; Vicariance. |
| Ano: 1997 |
URL: http://www.repository.naturalis.nl/record/504096 |
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| Arntzen, J.W.; Themudo, G. Espregueira; Wielstra, B.. |
| Newts of the genus Triturus (Amphibia, Caudata, Salamandridae) are distributed across Europe and adjacent Asia. In spite of its prominence as a model system for evolutionary research, the phylogeny of Triturus has remained incompletely solved. Our aim was to rectify this situation, to which we employed nuclear encoded proteins (40 loci) and mitochondrial DNA-sequence data (mtDNA, 642 bp of the ND4 gene). We sampled up to four populations per species covering large parts of their ranges. Allozyme and mtDNA data were analyzed separately with parsimony, distance, likelihood and Bayesian methods of phylogenetic inference. Existing knowledge on taxonomic relationships was confirmed, including the monophyly of the genus and the groups of crested newts (four... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Allozymes; Historical biogeography; Mitochondrial DNA-sequences; Triturus macedonicus; Triturus marmoratus; Vicariance; 42.82. |
| Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/262648 |
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| Registros recuperados: 15 | |
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