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1.
Aim The larval stages of marine taxa are often assumed to have an overriding influence on the phylogeographical structure of a species as well as on rates of speciation. Phylogeographical disjunctions in high‐dispersal marine taxa are generally attributed to historical events or contemporary ecological factors. The lack of genetic structure in low‐dispersal marine taxa is often ascribed to rafting by juveniles, yet few studies discuss the effects of historical conditions. Around peninsular Florida, there are three species of the crown conch, Melongena, which have direct‐developing, crawl‐away larvae. One of these species, M. corona, is subdivided into three subspecies. We refer to these five taxa as the corona complex. We assessed the validity of these taxa and tested for patterns of phylogeographical subdivision. Location Intertidal Florida and eastern Alabama, USA, Mexico and Panama. Methods The mitochondrial DNA cytochrome c oxidase subunit I, and ribosomal DNA 16S genes were sequenced from adult individuals representing all extant taxa of Melongena. Phylogenetic trees were constructed under maximum likelihood analysis (heuristic search with tree bisection–reconnection branch‐swapping) using the program paup *. Results Sequence variability in the complex was low and suggested no systematic or phylogeographical partitioning in the corona complex. The species complex probably consists of a single lineage exhibiting no clear pattern of genetic partitioning over the entire range. Main conclusions The present study supports the designation of only four extant species within the genus: M. corona, M. patula, M. melongena and M. bispinosa. The subspecies M. corona corona, M. c. johnstonei and M. c. altispira, and the species M. sprucecreekensis and M. bicolor, should all be considered to be M. corona. Surprisingly, even with very low larval and adult vagility, no population subdivisions were noted in our genetic analyses. Our analyses also substantiate the paraphyletic status of the family Melongenidae.  相似文献   

2.
Genetic markers are often used to trace the geographical origin of migrating birds. Such an approach has been used to attribute individuals of a given species to a given population, but it could also be applied to cryptic species, which are not fully diagnosable on the basis of their morphological appearance alone, despite often being genetically distinct. We sampled migrants of the Sylvia cantillans complex, which include cryptic taxa not readily identified on the basis of their appearance, at spring stopover sites in the central Mediterranean. We identified these individuals taxonomically using mitochondrial DNA sequence data. Molecular analyses enabled us to establish that four different taxa/clades of the Sylvia cantillans complex (two S. c. cantillans clades, S. c. albistriata and S. subalpina) migrate through the central‐western Mediterranean from Africa.  相似文献   

3.
Arribas, P., Andújar, C., Sánchez‐Fernández, D., Abellán, P. & Millán, A. (2012). Integrative taxonomy and conservation of cryptic beetles in the Mediterranean region (Hydrophilidae). —Zoologica Scripta, 00, 000–000. Because biodiversity inventory forms the basis for the effective conservation of species and habitats, there is an imperative need to discover and describe new species. A significant part of presently unknown biodiversity is constituted by cryptic species complexes, where traditional taxonomy usually fails due to a lack of clear taxonomic characters in the external structures of specimens. Integrative taxonomy offers a powerful tool to shed light on this part of encrypted biodiversity, combining multiple operational criteria in an evolutionary context in order to delineate species boundaries. The present study used an integrative approach to explore the species boundaries in a water beetle complex (Enochrus falcarius species complex) inhabiting saline streams, a rare and threatened habitat across the Mediterranean region. First, hypotheses about the candidate species on the basis of phylogenetic analyses and biogeographical information were proposed. Second, lineage divergence was evaluated between candidate species using (i) molecular cluster delimitation, (ii) morphometry (both linear body morphometrics and pronotum outlines) and (iii) ecological niche similarity estimates. We found divergence between candidate species on the basis of molecular, biogeographical and niche information, and consequently, four species were delimited within the E. falcarius complex (i.e. Enochrus jesusarribasi sp. n., Enochrus blazquezae sp. n., Enochrus risii sp. n. and Enochrus falcarius), despite the fact that they showed high morphological similarity. Enochrus falcarius, as previously considered, had not been proposed to be of conservational concern, because until now, it had been regarded as a single broadly distributed species in the Mediterranean region. However, the four entities here delimited within this species complex displayed characteristics that categorised them as vulnerable taxa. Hence, these results show how applying integrative taxonomy approaches and rapid vulnerability assessments to lineages from threatened habitats with the potential to comprise cryptic diversity could become a fundamental tool for biodiversity conservation, driving the discovery of cryptic species and consequently the modification of previous, inadequately evaluated vulnerability categorisations.  相似文献   

4.
An extensive phylogenetic analysis of the biflagellate genera, Chlamydomonas Ehrenberg and Chloromonas Gobi emend. Wille, was undertaken using 18S rDNA and rbcL gene sequence analysis. Emphasis was placed on 21 cold‐tolerant taxa of which 10 are from snow. These taxa occurred in four distinct clades each in the 18S rDNA and rbcL phylogenies, and when taken together suggest at least five distinct origins in cold habitats. Most of these taxa occur in a single clade (A), and all snow species occurred in this clade. In the rbcL and combined rbcL–18S rDNA analyses, the snow taxa fell into three groups. Two groups occurred in subclade 1: Chlamydomonas augustae Skuja CU, Chlamydomonas augustae UTEX, and Chlamydomonas sp.‐A and Chloromonas clathrata Korshikov, Chloromonas rosae Ettl CU, and Chloromonas rosae v. psychrophila var. nov. The third snow group, subclade 2, included three species with unique cell divisions, Chloromonas brevispina (Fritsch) Hoham, Roemer et Mullet, Chloromonas pichinchae (Lagerheim) Wille, and Chloromonas sp.‐D, and the basal Chloromonas nivalis (Chodat) Hoham et Mullet with normal cell divisions. This suggests that the snow habitat has been colonized at least twice and possibly three times in the history of these biflagellates. In the 18S rDNA tree, one cold‐tolerant Chloromonas species fell outside clade A: Chloromonas subdivisa (Pascher et Jahoda) Gerloff et Ettl. In the rbcL tree, three cold‐tolerant Chloromonas species fell outside clade A: Chloromonas subdivisa, Chloromonas sp.‐ANT1, and Chloromonas sp.‐ANT3. These results support previous findings that pyrenoids have been gained and lost several times within this complex.  相似文献   

5.
1. The occurrence of unresolved complexes of cryptic species may hinder the identification of the main ecological drivers of biodiversity when different cryptic taxa have different ecological requirements. 2. We assessed factors influencing the occurrence of Synchaeta species (monogonont rotifers) in 17 waterbodies of the Trentino‐South Tyrol region in the Eastern Alps. To do so, we compared the results of using unresolved complexes of cryptic species, as is common practice in limnological studies based on morphological taxonomy, and having resolved cryptic complexes, made possible by DNA taxonomy. 3. To identify cryptic species, we used the generalised mixed Yule coalescent (GMYC) model. We investigated the relationship between the environment and the occurrence of Synchaeta spp. by multivariate ordination using two definitions of the units of diversity, namely (i) unresolved species complexes (morphospecies) and (ii) putative cryptic species (GMYC entities). Our expectation was that resolving complexes of cryptic species could provide more information than using morphospecies. 4. As expected, DNA taxonomy provided greater taxonomic resolution than morphological taxonomy. Further, environmental‐based multivariate ordination on cryptic species explained a significantly higher proportion of variance than that based on morphospecies. Occurrence of GMYC entities was related to total phosphorus (TP), whereas no relationship could be found between morphospecies and the environment. Moreover, different cryptic species within the same morphospecies showed different, and even opposite, preferences for TP. In addition, the wide geographical distribution of haplotypes and cryptic species indicated the absence of barriers to dispersal in Synchaeta.  相似文献   

6.
Laboratory feeding experiments using two transgenic Bacillus thuringiensis (Bt) rape cultivars (Bt‐Westar and Bt‐Oscar) both expressing the Cry1Ac protein, and the corresponding untransformed lines, were carried out to study the effects of transgenic Bt rape on the non‐target herbivore Athalia rosae (L.) (Hymenoptera: Tenthredinidae). Furthermore, Cry1Ac protein concentration in Bt rape leaves, A. rosae larvae fed Bt rape, their faeces, eonymph instars, pupae, and adults were quantified using an enzyme‐linked immunosorbent assay (ELISA). There were no significant differences in mortality, larval development, and weight between transgenic Bt rape and non‐transgenic rape fed A. rosae. Additionally, we did not detect any significant differences in the fecundity and fertility of adult females either fed as larvae with transgenic Bt or with non‐transgenic rape. However, results of the ELISA indicated that Cry1Ac protein was detectable in larvae and faeces (Bt‐Westar 1.1 ± 0.2 and Bt‐Oscar 0.3 ± 0.2 µg Cry1Ac protein/g fresh weight) although this was less than in the leaf material, where concentrations were 2.2 ± 0.8 µg Cry1Ac protein/g fresh weight for Bt‐Westar and 7.5 ± 2.9 µg Cry1Ac protein/g fresh weight in Bt‐Oscar. In contrast, Cry1Ac protein could not be detected in eonymphs, pupae, or adults of A. rosae. Our results suggest that Cry1Ac protein in Bt rape does not have a significant effect on the herbivore A. rosae but the protein is still detectable after ingestion and excretion by these herbivores, thus providing the possibility of exposure to organisms other than herbivores.  相似文献   

7.
Spectroscopy information (functional groups and semiquantitative data) by Fourier transform infrared (FTIR) spectroscopy of Spongiophyton Kräusel emend. Chaloner et al. is reported for the first time, in an attempt to identify spectroscopic patterns that would differentiate species of these taxa. A total of 33 specimens identified as S. lenticularis, S. nanum and S. minutissimum and preserved as compressions were analysed. They come from the same fossiliferous horizon of one outcrop situated in the uppermost Middle Devonian São Domingos Formation of the Paraná Basin in southern Brazil. The results reveal that functional groups in the 3000–2800 and 1800–700 cm?1 wavenumber regions are present in all specimens. Infrared‐derived ratios (CH2/CH3, Al/Ox, Ox1/Ox2, C=O cont., C=C cont., Al2 and Ar/Al) and types of kerogen led to a comparison of the morphological characteristics of the studied material and indicate that compressions of S. lenticularis, S. nanum and S. minutissimum contain different organic compounds. S. nanum and S. minutissimum show higher oxidation and lower aromaticity of its organic matter than S. lenticularis. Additionally, S. lenticularis shows low A‐factor values, suggesting a composition similar to type III kerogen, while S. nanum and S. minutissimum showed intermediate to high A‐factor values, suggesting a composition similar to type II kerogen. In conclusion, the chemical‐analytical techniques and statistical analysis (using PCA technique) reveal a closer taxonomic relationship between S. nanum and S. minutissimum than either has with S. lenticularis, supporting their taxonomic separation, previously proposed in the literature on the basis of morphological features. Lastly, the chemical signatures support the hypothesis that links these enigmatic fossils to a type of lichen or other early inland plant.  相似文献   

8.
The first thorough molecular phylogeny of the superfamily Cleroidea, represented by 377 taxa, and the first with an emphasis on Trogossitidae, was undertaken. Maximum likelihood and Bayesian analyses were performed on a four‐gene dataset (18S, 28S, cox1, cytb) of 395 taxa (along with 18 outgroups), including all 16 currently recognized families of Cleroidea and all current and formerly recognized tribes of Trogossitidae. The superfamily as a whole received strong support in Bayesian analyses. On the basis of phylogenetic results, 18 families in Cleroidea are recognized, including three taxa elevated to family for the first time and two reinstated families. The former tribe Rentoniini (Trogossitidae: Peltinae) was strongly supported as a monophyletic group apart from the remainder of Trogossitidae, and is herein elevated to family status, Rentoniidae stat.n. Protopeltis was also found to be an isolated lineage and becomes Protopeltidae stat.n. Peltini + Larinotini were recovered as a weakly supported sister grouping; Peltini (including only Peltis) becomes Peltidae stat.rest. The trogossitid subfamily Lophocaterinae, to the exclusion of Decamerini, formed a clade which is here designated Lophocateridae stat.rest. and sensu n. The Trogossitinae tribes Calityini, Egoliini (represented by Egolia) and Larinotini were recovered apart from core Trogossitidae but showed no strong affinities to other taxa or congruence between analyses; they are here conservatively retained in Trogossitidae as Calityinae stat.rest. , Egoliinae stat.rest. and Larinotinae stat.rest. The genus Thymalus of the peltine tribe Thymalini was indicated with moderate to strong support as the sister group of the Decamerini (Trogossitidae: Lophocaterinae); together these represent Thymalidae stat.n. and sensu n. with subfamilies Decamerinae stat.rest. ( new placement ) and Thymalinae stat.n. The remainder of Trogossitinae, the tribes Trogossitini and Gymnochilini, formed a well‐supported clade which comprises the Trogossitidae: Trogossitinae sensu n. The tribe Gymnochilini syn.n. is synonymized with Trogossitini. The monotypic family Phloiophilidae was recovered, contradicting a recent placement within Trogossitidae. The melyrid lineage was recovered with moderate (maximum likelihood) to strong (Bayesian analyses) support and includes the families Phycosecidae, Rhadalidae, Mauroniscidae, Prionoceridae and Melyridae (including Dasytidae and Malachiidae). The genus Dasyrhadus is tentatively transferred from Rhadalidae to Mauroniscidae. The genus Gietella, once proposed as a distinct family but recently placed within Dasytidae, was recovered as strongly sister to Rhadalidae sensu n. , and we transfer it to that family as Gietellinae new placement . Attalomiminae (formerly Attalomimidae) syn.n. is synonymized with Melyridae: Malachiinae: Lemphini sensu n. Melyridae sensu n. includes only Dasytinae, Malachiinae and Melyrinae. Metaxina is returned to the Chaetosomatidae sensu n. , of which Metaxinidae syn.n. becomes a junior synonym. Resolution within Cleridae was generally poor, but a broadly defined Korynetinae stat rest. + Epiclininae received high support (Bayesian analyses). Outside of Trogossitidae, the main focus of this study, major rearrangements of the classification of Cleroidea were not undertaken, despite evidence indicating such changes are needed.  相似文献   

9.
10.
Species in cryptic complexes are, per definition, difficult to identify using morphological characters. One such complex was recently detected in the dung beetle Aphodius fimetarius (Linnaeus) sensu lato, an abundant dung beetle with a wide distribution. While the two component taxa, Aphodius fimetarius sensu stricto and Aphodius pedellus (De Geer) exhibit distinctly different karyotypes, the validity of subtle morphological characters proposed to distinguish between them has been debated. Given the variability and minor interspecific differences in external characters, the large‐scale distribution of respective taxa has remained unknown, as have potential differences in ecology and habits. In this study, we ask how A. fimetarius and A. pedellus can best be distinguished, whether the use of different types of characters (karyotypes, DNA sequences and morphological traits) results in consistent species identification, where these species occur and whether they exhibit ecological differences. In total, we inspected a material of 4401 individuals from across the globe, of which 183 were examined for both mtDNA sequences and morphology, 154 for both morphology and karyotype, and 9 (including the recently proposed neotype of Aphodius fimetarius) for all three types of characters. As a marker gene, we sequenced a 590 bp region of the cytochrome c oxidase I gene for 183 individuals. Overall, DNA sequences offered a clear‐cut distinction between taxa: sequences of A. fimetarius and A. pedellus differed by an average pairwise distance of 8.2%, whereas variation within species was only 0.9% for A. fimetarius and 0.5% for A. pedellus. Morphological and chromosomal characters offered species identifications consistent with that of molecular characters: karyotypes identified as A. pedellus consistently fell within one of the molecular clades, whereas karyotypes identified as A. fimetarius fell within the other clade. Likewise, the majority of individuals identified by morphological characters were assigned to the same species by sequence‐based characters. Both taxa thus defined were found to be Holarctic in distribution, with major sympatry within Central and Southern Europe and mixed patterns of sympatry within the US. Northern areas of Europe, Asia and North America are dominated by A. pedellus alone. Within A. pedellus, patterns of sequence diversity were indicative of a recent population expansion. In the western US, the phenology of a population of A. fimetarius was observed to significantly differ from that of a sympatric population of A. pedellus, thereby revealing an ecological difference between the two cryptic taxa. Overall, we conclude that all types of characters offered a consistent classification of the two species. Thus, the laborious karyotyping techniques used to originally establish the presence of two cryptic taxa can now be substituted by characters more easily applied to large ecological samples. Using this approach of integrative taxonomy, we were able to establish the global distribution and species‐specific ecology of these ecologically important cryptic taxa. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:4033473E-8BF7-40F4-852D-916E4F858593 .  相似文献   

11.
Mounting evidence of cryptic species in a wide range of taxa highlights the need for careful analyses of population genetic data sets to unravel within‐species diversity from potential interspecies relationships. Here, we use microsatellite loci and hierarchical clustering analysis to investigate cryptic diversity in sympatric and allopatric (separated by 450 km) populations of the widespread coral Seriatopora hystrix on the Great Barrier Reef. Structure analyses delimited unique genetic clusters that were confirmed by phylogenetic and extensive population‐level analyses. Each of four sympatric yet distinct genetic clusters detected within S. hystrix demonstrated greater genetic cohesion across regional scales than between genetic clusters within regions (<10 km). Moreover, the magnitude of genetic differentiation between different clusters (>0.620 GST) was similar to the difference between S. hystrix clusters and the congener S. caliendrum (mean GST 0.720). Multiple lines of evidence, including differences in habitat specificity, mitochondrial identity, Symbiodinium associations and morphology, corroborate the nuclear genetic evidence that these distinct clusters constitute different species. Hierarchical clustering analysis combined with more traditional population genetic methods provides a powerful approach for delimiting species and should be regularly applied to ensure that ecological and evolutionary patterns interpreted for single species are not confounded by the presence of cryptic species.  相似文献   

12.
The diatoms (Bacillariophyta) from a coastal lagoon from the Diablas wetlands (Isla Isabela, the Galápagos Islands) were studied in material from surface samples and a sediment core spanning the past 2,700 years in order to examine evidence of diatom evolution under geographic isolation. The total number of taxa found was ~100. Ultrastructural variation in valve morphology between members of Galápagos taxa was used to describe 10 species from the genus Navicula sensu stricto, which are new to science. Four taxa: N. isabelensis, N. isabelensoides, N. isabelensiformis, and N. isabelensiminor, shared several key characteristics that may be indicative of a common evolutionary heritage; these species therefore provide possible evidence for the in situ evolution of diatoms in the Galápagos coastal lagoons. Shared morphological characteristics include: (i) stria patterning in the central area, (ii) an elevated and thickened external raphe‐sternum, (iii) external central raphe endings that are slightly deflected toward the valve primary side, and (iv) an arched valve surface. To explain these findings, two models were proposed. The first suggested limited lateral diatomaceous transport of Navicula species between the Galápagos and continental South America. Alternatively, these new species may be ecological specialists arising from the unique environmental conditions of the Galápagos coastal lagoons, which restrict the colonization of common diatom taxa and enable the establishment of novel, rare species. The Diablas wetlands are an important site for diatom research, where local‐scale environmental changes have combined with global‐scale biogeographic processes resulting in unique diatom assemblages.  相似文献   

13.
Although species delimitation can be highly contentious, the development of reliable methods to accurately ascertain species boundaries is an imperative step in cataloguing and describing Earth's quickly disappearing biodiversity. Spider species delimitation remains largely based on morphological characters; however, many mygalomorph spider populations are morphologically indistinguishable from each other yet have considerable molecular divergence. The focus of our study, the Antrodiaetus unicolor species complex containing two sympatric species, exhibits this pattern of relative morphological stasis with considerable genetic divergence across its distribution. A past study using two molecular markers, COI and 28S, revealed that A. unicolor is paraphyletic with respect to A. microunicolor. To better investigate species boundaries in the complex, we implement the cohesion species concept and use multiple lines of evidence for testing genetic exchangeability and ecological interchangeability. Our integrative approach includes extensively sampling homologous loci across the genome using a RADseq approach (3RAD), assessing population structure across their geographic range using multiple genetic clustering analyses that include structure , principal components analysis and a recently developed unsupervised machine learning approach (Variational Autoencoder). We evaluate ecological similarity by using large‐scale ecological data for niche‐based distribution modelling. Based on our analyses, we conclude that this complex has at least one additional species as well as confirm species delimitations based on previous less comprehensive approaches. Our study demonstrates the efficacy of genomic‐scale data for recognizing cryptic species, suggesting that species delimitation with one data type, whether one mitochondrial gene or morphology, may underestimate true species diversity in morphologically homogenous taxa with low vagility.  相似文献   

14.
The importance and abundance of cryptic species among invertebrate taxa is well documented. Nowadays, taxonomic, phylogenetic and conservation biological studies frequently use molecular markers to delineate cryptic taxa. Such studies, however, often face the problem of the differential resolution of the molecular markers and techniques involved. This issue is explored in the present study of cryptic taxa within the terrestrial slug complex Arion subfuscus/fuscus in continental north-west Europe. To this end, morphological, allozyme and mitochondrial 16S rDNA sequence data have been jointly evaluated. Using allozyme data and gonad type, two distinct groups were consistently delineated, even under sympatric conditions. The 16S rDNA data strongly supported both those groups and even suggested the presence of three distinct taxa within one of them. However, in view of: (1) the allopatric distribution of three OTUs, (2) the lack of allozyme or morphological differentiation, and (3) the extremely high degree of intraspecific mtDNA variation reported in pulmonate gastropods, they are, for the time being, not regarded as valid species under the biological species concept. By means of 16S rDNA and allozyme data, the position of type and topotype material of A. subfuscus s.s. and A. fuscus relative to the newly defined OTUs was determined, thus clarifying the nomenclature of this species complex. Additionally, gonad type proved to be a useful character for distinguishing the two species in north-west Europe.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 83 , 23–38.  相似文献   

15.
The formation of stable genetic boundaries between emerging species is often diagnosed by reduced hybrid fitness relative to parental taxa. This reduced fitness can arise from endogenous and/or exogenous barriers to gene flow. Although detecting exogenous barriers in nature is difficult, we can estimate the role of ecological divergence in driving species boundaries by integrating molecular and ecological niche modelling tools. Here, we focus on a three‐way secondary contact zone between three viper species (Vipera aspis, V. latastei and V. seoanei) to test for the contribution of ecological divergence to the development of reproductive barriers at several species traits (morphology, nuclear DNA and mitochondrial DNA). Both the nuclear and mitochondrial data show that all taxa are genetically distinct and that the sister species V. aspis and V. latastei hybridize frequently and backcross over several generations. We find that the three taxa have diverged ecologically and meet at a hybrid zone coincident with a steep ecotone between the Atlantic and Mediterranean biogeographical provinces. Integrating landscape and genetic approaches, we show that hybridization is spatially restricted to habitats that are suboptimal for parental taxa. Together, these results suggest that niche separation and adaptation to an ecological gradient confer an important barrier to gene flow among taxa that have not achieved complete reproductive isolation.  相似文献   

16.
Multiple species of troglomorphic, spring‐associated Stygobromus amphipods, including the endangered, narrow‐range endemic Stygobromus pecki, occupy sites in the Edwards Plateau region of North America. Given the prevalence of cryptic diversity observed in disparate subterranean, animal taxa, we evaluated geographical genetic variation and tested whether Stygobromus contained undetected biodiversity. Nominal Stygobromus taxa were treated as hypotheses and tested with mitochondrial sequence cytochrome oxidase C subunit 1, nuclear sequence (internal transcribed spacer region 1), and AFLP data. Stygobromus pecki population structure and diversity was characterized and compared with congeners. For several Stygobromus species, the nominal taxonomy conflicted with molecular genetic data and there was strong evidence of significant cryptic diversity. Whereas S. pecki genetic diversity was similar to that of congeners, mitochondrial data identified two significantly diverged but sympatric clades. AFLP data for S. pecki indicated relatively recent and ongoing gene flow in the nuclear genome. These data for S. pecki suggest either a substantial history of isolation followed by current sympatry and ongoing admixture, or a protracted period of extremely large effective population size. This study demonstrates that Edwards Plateau Stygobromus are a complex, genetically diverse group with substantially more diversity than currently recognized. © 2013 The Linnean Society of London  相似文献   

17.
The phylogenetic relationships within the genus Plecotus were assessed using molecular as well as morphological methods. With only three species missing, our study is based on an almost comprehensive taxonomic sampling. The genetic analysis comprised 151 individuals from throughout the range. Sequences of two mitochondrial sections, parts of the 16S rRNA gene (16S) and of the control region (CR) were analysed. The morphological analysis of cranial and external characters comprised 697 individuals, including 10 holotypes and one lectotype. Data from 15 craniometric characters of 442 specimens were used in the multivariate analyses. The molecular data identified nine primary clades representing 11 species, 10 of which could be assigned to described taxa, whereas one was described as a new species, Plecotus strelkovi Spitzenberger sp. nov. The tree based on 16S revealed two major lineages, one consisting of only one primary clade restricted to the Mediterranean, the other consisting of eight primary clades representing Eurasian taxa. The morphological analysis revealed five additional species, two of them not described. Together with the recently described P. taivanus, P. sardus and P. balensis, which were not included in our analysis, the genus Plecotus comprises at least 19 more or less cryptic species. Phylogenetic and phenetic analyses resulted in similar but not completely concordant arrangements of the species. The proposed classification relies mainly on the tree based on 16S sequences. The current distribution indicates that 16 species can be linked to arboreal refugia, three to eremial refugia. We assume that speciation within the gleaning, rather slow flying long‐eared bats is due to a multitude of disruption and isolation processes within a formerly continuous range of the broad‐leaved Arcto‐Tertiary forest in which Plecotus probably originated. An exact calibrated molecular dating of the splits is not possible. The Early Oligocene age of the presumed ancestor of the Plecotini and a correlation of the molecular diversifications with palaeogeographic reconstructions suggest that the divergence of the two major lineages may have occurred already during the Middle Miocene, 14.5 Mya.  相似文献   

18.
The number of Miniopterus bat species on Madagascar and the nearby Comoros islands (Malagasy region) has risen from four to 11. These recently described cryptic taxa have been differentiated primarily based on molecular markers and associated a posteriori morphological characters that corroborate the different clades. Members of this Old World genus are notably conservative in morphology across their range. Several sites on Madagascar hold up to four small‐bodied taxa of this genus that are morphologically similar to one another, although they can be distinguished based on the tragus, an ear structure associated with echolocation. Miniopterus often emit species‐specific calls. In the present study, we analyze the bioacoustics of the 11 species of Miniopterus currently recognized from the Malagasy region, with an initial identification of the 87 recorded and collected individuals based on molecular markers and certain morphological characters. In most cases, bioacoustic parameters differentiate species and have taxonomic utility. Miniopterus griveaudi populations, which occur on three islands (Madagascar, Anjouan, and Grande Comore), showed no significant differences in peak echolocation frequencies. After running a discriminant function analysis based on five bioacoustic parameters, some mismatched assignments of Malagasy species were found, which include allopatric sister‐taxa and sympatric, phylogenetically not closely‐related species of similar body size. Because the peak echolocation frequencies of two species (Miniopterus sororculus and Miniopterus aelleni) were independent of body size, they were acoustically distinguishable from cryptic sympatric congeners. The small variation around the allometric relationship between body size and peak echolocation frequency of Malagasy Miniopterus species suggests that intraspecific communication rather than competition or prey detection may be the driver for the acoustic divergence of these two species. Our well‐defined echolocation data allow detailed ecological work to commence aiming to test predictions about the relative roles of competition, prey availability, and social communication on the evolution of echolocation in Malagasy Miniopterus species. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 284–302.  相似文献   

19.
Investigating complex parasitic life cycles is important for understanding the major fitness components that drive the evolution of host–parasite systems. The rare condition of heterotrophic heteronomy, in which the sexes utilize disparate host taxa, is a poorly understood complex parasitic lifestyle. One of only two known examples occurs in the Myrmecolacidae, an unusual family of the parasitoid order Strepsiptera (Insecta), in which males parasitize ants while females parasitize grasshoppers, crickets, and praying mantids. Here, we reconstruct the evolutionary pattern and timescale of host‐use in a set of morphologically cryptic myrmecolacid taxa currently identified as Caenocholax fenyesi. We find that (i) C. fenyesi contains at least ten cryptic lineages consistent with separate species; (ii) Fossil evidence suggests a very low molecular clock rate and an ancient origin for cryptic lineages; (iii) Diversity among Caenocholax species is partitioned by geography and host association of the female; and (iv) Switches in host usage are uncoupled between the sexes, with changes in female host preference accompanying diversification. This study represents the first phylogeographical analysis of any strepsipteran, and the first molecular examination of host‐use for a heterotrophic heteronomous taxon. Our results have implications for the understanding of evolution, host usage and estimated species richness in parasitic taxa.  相似文献   

20.
Complexes of cryptic species are rapidly being discovered in many parasite taxa, including trematodes. However, after they are found, cryptic species are rarely distinguished from each other with respect to key ecological or life history traits. In this study, we applied an integrative taxonomic approach to the discovery of cryptic species within Stegodexamene anguillae, a facultatively progenetic trematode common throughout New Zealand. The presence of cryptic species was determined by the genetic divergence found in the mitochondrial cytochrome c oxidase I gene, the 16S rRNA gene and the nuclear 28S gene, warranting recognition of two distinct species and indicating a possible third species. Speciation was not associated with geographic distribution or microhabitat within the second intermediate host; however frequency of the progenetic reproductive strategy (and the truncated life cycle associated with it) was significantly greater in one of the lineages. Therefore, two lines of evidence, molecular and ecological, support the distinction between these two species and suggest scenarios for their divergence.  相似文献   

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