Journal of Zoological Systematics and Evolutionary Research最新文献

Coendou comprises the most speciose genus in Erethizontidae, with 15 currently recognized species. Although several taxonomic studies in the last two decades have unveiled part of its diversity, the most widespread Neotropical taxon Coendou prehensilis has received limited attention. Here, we combined morphological and molecular datasets to infer the phylogenetic relationships of the species in the genus and revise the taxonomy of the C. prehensilis complex. We found four morphotypes and three well-supported monophyletic clades within C. prehensilis. These three clades represent valid species: C. prehensilis (restricted to the north of the Atlantic Forest), C. baturitensis (occurring in the eastern Amazonian and montane forests enclaves in the Caatinga), and C. longicaudatus (two subspecies, C. l. longicaudatus from the Amazon and C. l. boliviensis from Cerrado and Chaco). Furthermore, we recovered three morphologically diagnosable clades within Coendou, for which we assigned subgeneric names. Coendou (Coendou) comprises six species (C. baturitensis, C. longicaudatus, C. mexicanus, C. prehensilis, C. quichua, and C. rufescens), Coendou (Sphiggurus) includes five taxa (C. bicolor, C. insidiosus, C. nycthemera, C. speratus, and C. spinosus), and the third subgenus we named Coendou (Caaporamys) subgen. nov, comprising C. melanurus (type species), C. vestitus, C. pruinosus, C. ichillus, and C. roosmalenorum.

Sigmodontine rodents colonized South America in Late Miocene or earlier, leading to the clade Oryzomyalia, which rapidly radiated in distinct lineages and occupied almost all continental habitats, in a pattern classically interpreted as an adaptive radiation. Nevertheless, no evidence of strong influence of niche diversification on the evolution of cranial and mandibular morphology, or of deceleration in rates of phenotypic evolution in these structures over time following niche saturation, as expected according to the Ecological Opportunity model, has been detected. Here, we investigated morphometric variation among 59 oryzomyalian species using phylogenetically informed comparative analyses for testing (1) if the diversification of locomotor habits played an important role in shaping the morphology of the appendicular skeleton, and (2) if the disparification of appendicular skeleton showed high rates at the early diversification of Oryzomyalia and then has deaccelerated. Results showed that the different locomotor habits are associated with different shapes in both the forelimb and hindlimb, and selection of evolutionary models suggested that each locomotor habit was associated with their own adaptive optima. Moreover, the most extreme and specialized phenotypes, found in the semifossorial species Geoxus valdivianus, Blarinomys breviceps, and Paynomys macronyx, seem to have appeared after events of acceleration in the rates of morphological evolution. On the other hand, no evidence of a reduction in the rate of evolution over time was detected. The results suggest that the acquisition of different locomotor habits in oryzomyalians was associated with morphological specializations in the appendicular skeleton guided by natural selection and that, especially in the case of the evolution of fossoriality, there was a marked change in evolutionary regimes, generating highly modified phenotypes after acceleration of the pace of morphological changes. Despite the strong association between diversification of locomotor niches and evolution of the appendicular skeleton, the diversification of oryzomyalians does not seem to have experienced niche saturation, as noted in some other adaptive radiation events on Neotropics.

We advance on the knowledge of Eigenmanniinae by proposing a hypothesis of phylogenetic relationships based on the parsimony analysis of a diverse set of 144 anatomical characters, 12% of them treated as quantitative and 88% treated as qualitative (8% external morphology, 51% osteology, 21% myology, and 8% neuroanatomy). Thirty-seven of 45 valid species of Eigenmanniinae are examined in the study, including the incertae sedis species “Eigenmannia” goajira. The final tree yields new insights on species relationships, thus, producing a new classification to Eigenmanninae. Our analysis recovered the monophyly of Eigenmanniinae, Archolaemus, Eigenmannia, and Rhabdolichops. Eigenmannia is proposed as monophyletic based on four morphological synapomorphies, one of which exclusive to the genus. Japigny is proposed to be the sister group of all remaining Eigenmanniinae and “E.” goajira to be the sister group of Archolaemus. The hypothesis of monophyly of Distocyclus including D. conirostris and D. guchereauae is rejected. Consequently, D. guchereauae is included in Eigenmannia, and a new genus is established to include “E.” goajira. A taxonomic key to all genera is provided. In addition, this study highlights the critical role played by a diverse set of anatomical and quantitative characters without discretization on phylogenetic reconstructions.

The description of Vipera walser from the Northern Italian Alps as a new species (Ghielmi et al., 2016, Journal of Zoological Systematics and Evolutionary Research, 54, 161) was one of the most unexpected surprises of European herpetology in the 21st century. In mitochondrial (mt) DNA, it is closely related to a group of vipers only present in the Caucasus region and Northeastern Anatolia. However, its morphology is similar to the V. berus populations that inhabit nearby mountains in the Swiss-Italian Alps, which raises questions on its relationships and status. We thus sequenced five nuclear (nu) genes to determine the position of V. walser relative to V. berus and to the Caucasian/Northeastern Anatolian vipers in nuDNA. We also reanalyzed five previously sequenced mtDNA fragments. NuDNA markers recovered V. walser as closely related to Italian populations of V. berus and not to the Caucasian/Anatolian species, thus contradicting the mtDNA phylogeny. We checked that each of the five mtDNA fragments independently amplified by Ghielmi et al. (2016, Journal of Zoological Systematics and Evolutionary Research, 54, 161) produced individual gene trees compatible with the concatenated mtDNA phylogeny, thus excluding the hypothesis that NUMTs sequencing generated the mtDNA relationships reported by Ghielmi et al. (2016, Journal of Zoological Systematics and Evolutionary Research, 54, 161). Given the low level of nuclear differentiation between V. walser and the Italian population of V. berus, we argue that ancient admixture between V. berus and the ancestral population of V. walser is the most likely explanation for this case of cyto-nuclear discordance and we discuss the consequences of these results on the systematic status of V. walser.

The Peloponnese wall lizard, Podarcis peloponnesiacus, is endemic to the Peloponnese. Although the phylogeny and species diversity of the Balkan species of Podarcis have been extensively studied, the intraspecific relationships of P. peloponnesiacus are not yet well defined. The aim of this study was to investigate the intraspecific diversity in this species and clarify its taxonomic status by analyzing eight gene fragments (two mitochondrial and six nuclear) and several morphological traits, typically used for systematic inferences within the genus Podarcis. Together with ecological niche modeling, we provided an integrative evaluation of the differentiation between lineages. The combination of several phylogenetic, species delimitation, and chronophylogenetic analyses revealed the existence of two highly supported and divergent clades with a distinct geographical and parapatric distribution and high niche overlap. The differentiation of the two clades dates back to the Pleistocene and is probably correlated with the paleogeography of the Peloponnese. These clades also differed in several phenotypic traits, which, however, exhibit extensive overlap and are not fully diagnostic. The combination of the above results allowed us to identify the two revealed clades as distinct species.

Highlands are the most heterogeneous and complex biogeographic regions of Mexico. Species inhabiting these regions have been exposed to geologic events and climatic fluctuations in the past causing limited historical gene flow that resulted in structured genetic variation and high endemism. We examined the genetic variation of the mouse Peromyscus hylocetes throughout its geographic distribution within the Trans-Mexican Volcanic Belt (TVB), to estimate its current environmental suitability, habitat connectivity, and to reconstruct its evolutionary history by inferring the role of past events and abiotic factors. Two main genetic clusters corresponding to the west and east range of the species distribution were detected. Gene flow occurred largely from the west to the east cluster. Peromyscus hylocetes and P. aztecus diverged during the Pliocene–Pleistocene at the central-south region of the TVB. We hypothesized that after this divergence, P. hylocetes colonized the TVB during the Pleistocene and later expanded its distribution to the western TVB. Due to the climatic oscillations in the late Pleistocene, populations were restricted in western TVB during the warmer periods, and displacements occurred during colder periods from the west to the central TVB on several episodes.

Triatoma infestans (Hemiptera, Reduvidae) is the main vector of Chagas disease in South America between the latitudes 10° and 46° S. The analysis of the spatial genetic structure of populations at fine scale can provide insight into the dynamic population and evolutionary process of T. infestans and a complementary approach to help improve vector control strategies. Spatio-temporal analysis of the genetic structure of T. infestans populations was performed using inter-simple sequence repeats markers. A total of 242 polymorphic bands were detected from 234 individuals captured in different houses from the locality of San Martín and in one surrounding area (Capayan department, Catamarca province, Argentina) in October 2007 and May 2010. Significant levels of genetic differentiation were detected among the collection sites in both temporal samples, including the different sampled sites within the same house. These results confirm a high degree of subdivision in T. infestans populations. Comparative analysis between the first and the second sample indicated that they form two different groups. The genetic differentiation level was higher among samples from the second capture compared to the first. It is probable that in subdivided populations, when restricted gene flow is sustained over time, the genetic drift leads to accentuate the differentiation among subpopulations. The spatial autocorrelation analysis indicated that the dispersion range could occur around 500–550 m. Therefore, the probability of reinfestation by active dispersal of the insect could be reduced by implementing control and surveillance within an approximate radius of 500–550 m around the infested area.

Wing interference patterns (WIPs) are stable structural color reflections of insect transparent wings. The WIP colors are the result of thin-film interference and vary according to wing thickness and other wing characteristics. These patterns have been thought to play a display role during courtship. Recent empirical studies concluded that WIPs affect male drosophilid attractiveness and that WIP evolution is driven by sexual selection. However, these studies did not account for body size variation, a variable that has been demonstrated to be sexually selected and that may be related to wing thickness and WIP color. I consider herein the possibility that body size could be the trait being selected in these studies, and not the WIPs, with the latter being indirectly selected. A first step to consider this alternative hypothesis would be to demonstrate the correlation between WIPs and body size. I analyzed whether such correlation exists through the phylogenetic tree of the genus Coniceromyia (Diptera: Phoridae) by comparing evolutionary models assuming dependent and independent evolution of both traits. I also investigated whether WIPs are correlated to body size within two species of this genus. Strong evidence was found in favor of the correlation between WIPs and body size in the tree analyzed and within one of the two species. If these results are confirmed as a general pattern, the signaling role of WIPs and their direct relation to sexual selection may be questioned by the alternative hypothesis that body size could be the sexually selected trait in recent studies' experiments.

Many studies have confirmed the impact of the environment on the brain. However, it is still controversial whether the cause of the change is phenotypically plastic or heritable. In this study, we studied morphological variations of the brain among Gambusia affinis obtained from 10 different populations in China. We found that the sizes of total brain and brain regions were affected by climatic gradients. For instance, there was a decrease in the volume of olfactory bulbs, optic tectum, corpus cerebelli, and total brain from north to south. Common-garden experiments indicated that the variations in the sizes of the hypothalamus and the total brain were heritable, while that of other brain regions were phenotypically plastic. Variation in brain morphology of wild fish supports the mosaic hypothesis. The common-garden experiments provide a reference for heritability estimates and phenotypic plasticity of brain volumes. In addition, our study has laid the foundation for in-depth research on the adaptive evolution of the brain of G. affinis.

We studied molecular variability to clarify intraspecific differentiation and phylogenetic relationships in three pine vole species (genus Microtus, subgenus Terricola): Microtus subterraneus, Microtus daghestanicus, and Microtus majori. Multilocus analysis was performed using the entire mitochondrial cytb gene and fragments of nuclear BRCA1, IRBP, and XIST genes. Results confirmed separation of the species, especially M. majori compared with M. daghestanicus and M. subterraneus. These species showed different molecular polymorphism in the genetic markers. We identified two close forms of M. majori, differing in cytb gene and the nuclear gene XIST; one form inhabits the northern slopes of the Greater Caucasus, another the Transcaucasia. Separation of M. daghestanicus populations from North Ossetia and the others was clear. Microtus subterraneus populations from southern Europe and Asia Minor were characterized by maximal genetic heterogeneity; the specimen from Samsun (northern Asia Minor) appeared to be most distant from the others. Despite polymorphism in the chromosome number in M. subterraneus populations from the East European Plain, they possess a depleted gene pool. Results indicated that M. subterraneus colonized the East European Plain in the Holocene, and chromosome variability originated in this part of the species' range as a result of chromosomal fission and quick fixation of the arrangement in northern populations. We argue that differences in the genetic differentiation patterns of Terricola species are mainly due to their ecological peculiarities.