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Вверх

Литература по земноводным

Josh Van Buskir // Evolution, 56(2), 2002, pp. 361–370
 

The hypothesis that predator-induced defenses in anuran larvae are maintained by divergent selection across multiple predation environments has not been fully supported by empirical results. One reason may be that traits that respond slowly to environmental variation experience a fitness cost not incorporated in the standard adaptive model, due to a time lag between detecting the state of the environment and expressing the phenotypic response. I measured the rate at which behavior and morphology of Rana temporaria tadpoles change when confronted with a switch in the predation environment at two points in development. Hatchling tadpoles that had been exposed during the egg stage to Aeshna dragonfly larvae were not phenotypically different from those exposed as eggs to predator-free conditions, and both responded similarly to post-hatching predator treatments. When 25-day-old tadpoles from treatments with and without dragonflies were subjected to a switch in the environment, their activity budgets reversed completely within 24–36 h, and their body and tail shape began changing significantly within 4 days. The behavioral response was conservative: Tadpoles switched from high-risk to predator-free treatments were slower to adjust their activity. The study confirmed that behavioral traits are relatively labile and exhibit strong plasticity, but it did not reveal such a pattern at the level of individual traits: Morphological traits that developed slowly did not show the least plasticity. Thus, I found that differences in lability of traits were useful for predicting the magnitude of plasticity only for fundamentally different kinds of characters.

Jing Che, Junfeng Pang, Hui Zhao, Guan-fu Wu, Er-mi Zhao, Ya-ping Zhang // Molecular Phylogenetics and Evolution 43 (2007) 1–13
 

Phylogenetic relationships among representative species of the subfamily Raninae were investigated using approximately 2000 base pairs of DNA sequences from two mitochondrial (12S rRNA, 16S rRNA) and two nuclear (tyrosinase, rhodopsin) genes. Phylogenetic trees were reconstructed using maximum parsimony, Bayesian, and maximum likelihood analyses. Comparison between the nuclear and mitochondrial Wndings suggested that our Wnal combined data has higher resolving power than the separate data sets. The tribes Stauroini and Ranini formed a sistergroup relationship, and within Ranini, ten major clades were consistently resolved among all analyses based on the Wnal combined data, although the phylogenetic relationships among the ten clades were not well resolved. Our result refuted several previous taxonomic divisions: the genus Pseudoamolops was invalid, and the monophyly of the genera Amolops and Rana were not supported. We suggest elevating Raninae to familial status, and recognizing within the family, at least twelve genera including Staurois, Meristogenys, Clinotarsus, Amolops, Hylarana, Babina, Odorrana, Pseudorana, Rana, Lithobates, Glandirana, and Pelophylax. A broader sampling of species and data from more molecular markers are needed to conWdently resolve the phylogenetic relationships among Ranidae.

Jean-Matthieu Monnet and Michael I. Cherry //Proc. R. Soc. Lond. B (2002) 269, 2301–2307
 
Several hypotheses have been proposed to explain the direction and extent of sexual size dimorphism in anurans (in which males are usually smaller than females) as a result of sexual selection. Here, we present an analysis to test the hypothesis that sexual dimorphism in anurans is largely a function of differences between the sexes in life-history strategies. Morphological and demographic data for anurans were collected from the literature, and the mean size and age in each sex were calculated for 51 populations, across 30 species and eight genera. Comparisons across 14 Rana species, eight Bufo species and across the genera showed a highly significant relationship between size dimorphism, measured using the female–male size ratio, and mean female–male age difference. A comparison of a subset of 17 of these species for which phylogenetic information was available, using the method of independent contrasts, yielded a similar result. These results indicate that most of the variation in size dimorphism in the anura can be explained in terms of differences in the age structure between the sexes in breeding populations. If sexual selection has an effect on size dimorphism in anurans, it is likely to be only a secondary one.
Alain Dubois & Jean Raffaëlli //Alytes, 2009, 26 (1-4): 1-85.
 

Several recent studies, particularly dealing with molecular phylogeny, have improved our knowledge of the relationships within the salamander family Salamandridae. However, some only of these ndings have resulted in formal taxonomic changes. In order to homogenize this taxonomy, we hereby recognize several new taxa at various ranks from subfamily to subspecies, and we propose a new comprehensive ergotaxonomy and nomenclature for the whole family. We also discuss some general questions of taxonomy and nomenclature, in particular regarding the concepts of species and genus, the use of taxonomic categories and nomenclatural ranks in taxonomy, the relationships between taxonomy and conservation biology, the various modes of denition of taxa (including diagnoses and cladognoses), the structure and length of scientic nomina, the status of online databases providing taxonomic and nomenclatural data, the designation of nucleospecies of nominal genera and the nomenclatural status of various nomina.

 

 
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