首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
DNA sequences of the mitochondrial nd6 gene and the non-repetitive part of the pseudo-control region (PsiCR) were isolated from 101 individuals to analyze the phylogenetic relationships among all buzzards of the genus Buteo and other buteonine genera. Comparisons of the two marker sequences indicate that the PsiCR evolved two times faster than the nd6 gene. The PsiCR proved to be an efficient, neutral genetic marker sequence for phylogenetic analyses at the intrageneric level, especially suitable for analyses based on old tissues, where only short fragments can be obtained. The molecular data set implies a neotropical origin of the genus Buteo. Monophyly of the genus Buteo as currently defined is contradicted due to the positions of Asturina nitida, Geranoaetus melanoleucus, Buteo magnirostris, and Buteo leucorrhous. These findings suggest several taxonomic consequences. A. nitida and G. melanoleucus should be included into the genus Buteo. Moreover, B. leucorrhous should be transferred into the genus Percnohierax (which clusters with Parabuteo), and B. magnirostris into the genus Rupornis. According to this classification of the genus Buteo, the basal lineage of the genus is formed by a clade containing Buteo polyosoma, Buteo poecilochrous, and Buteo melanoleucus. The "woodland buteos" form a paraphyletic assemblage with B. magnirostris as a clearly separated lineage basal to the genus Buteo.  相似文献   

2.
The Seychelles harbour an endemic frog family, the Sooglossidae, currently containing two genera: Sooglossus , with three species, and Nesomantis , with one species. These unique frogs are generally considered to be basal neobatrachians, although their relationships to other neobatrachian taxa, except the Nasikabatrachidae, remain unresolved. Our molecular phylogeny based on a dataset consisting of fragments of the nuclear rag-1 and rag-2 genes, as well as mitochondrial 16S rRNA in representatives of the major neobatrachian lineages, confirmed the previously postulated Sooglossidae + Nasikabatrachidae clade and the placement of the South American Caudiverbera with the Australian Myobatrachidae, but did not further resolve the position of sooglossids. Our results do, however, unambiguously show sooglossids to be monophyletic but the genus Sooglossus to be paraphyletic, with the type species Sooglossus sechellensis being more closely related to Nesomantis thomasseti than to Sooglossus gardineri and Sooglossus pipilodryas , in agreement with morphological, karyological, and bioacoustic data. As a taxonomic consequence, we propose to consider the genus name Nesomantis as junior synonym of Sooglossus , and to transfer the species thomasseti to Sooglossus . For the clade composed of the species gardineri and pipilodryas , here, we propose the new generic name Leptosooglossus . A significant genetic differentiation of 3% was found between specimens of Sooglossus thomasseti from the Mahé and Silhouette Islands, highlighting the need for further studies on their possible taxonomic distinctness.   © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 347–359.  相似文献   

3.
Aim The phylogeny of the enid land-snail genus Pachnodus was determined in order to provide information on biogeographical patterns within the granitic Seychelles islands. Location The genus Pachnodus is endemic to the granitic islands of Seychelles (Mahé, Silhouette, Praslin, La Digue and Fregate). Methods Phylogeny was determined using a cladistic analysis of nineteen shell and soft-body anatomy characters. The outgroup used was the central-east African genus Cerastus. Results The proposed phylogeny indicates that the genus divided into two distinct subgenera early in its history. Subsequent speciation occurred in parallel in the two subgenera, resulting in several islands supporting at least two distinct species representing the two subgenera. Main conclusions The pattern of speciation is largely explicable by vicariance as a result of sea-level rises, followed by habitat specialisation and further speciation. The pattern is in contrast to previously published scenarios for other taxa in the islands and indicates significant differences between evolutionary and habitat factors in the biogeography of the Seychelles fauna  相似文献   

4.
The parrot genus Prioniturus occurs in the oceanic Philippines, Palawan and Wallacea, a geologically dynamic region with a complex history of land and sea. The described taxa of Prioniturus have been variously placed in different assemblages, and different numbers of species have been recognized. However, a phylogenetic framework is so far lacking. This would be the prerequisite to reconstructing dispersal and colonization patterns of Prioniturus across and within Wallacea and the Philippines. Following our robustly supported phylogenetic hypothesis based on two mitochondrial genes, we propose to treat Prioniturus mindorensis comb. nov. as well as Prioniturus montanus and Prioniturus waterstradti as separate species. In Prioniturus discurus discurus and Prioniturus discurus whiteheadi, further studies using additional data and specimens are necessary to clarify their taxonomic status. This result is congruent with other studies demonstrating that alpha diversity of the Philippine avifauna is strongly underestimated. According to our biogeographic reconstruction, Prioniturus has diversified by a complex combination of colonization of islands and subsequent divergence in allopatry among and within island groups. Dispersal between Sulawesi/Wallacea and the Philippines occurred twice and documents a rare case of faunal exchange between these two regions.  相似文献   

5.
Two Orthotrichum species of the subgenus Orthophyllum were compared with other representatives of this genus using internally transcribed spacer regions 1 and 2, the chloroplast trn H-psbA region, and inter-simple sequence repeat (ISSR) and intron-exon splice conjunction (ISJ) markers. The ISSR and ISJ markers used revealed many bands and mutations specific only to O. Gymnostomum and O. Obtusifolium. Phylogenetic analysis clearly supported previous concepts postulating that species of the subgenus Orthophyllum should be recognized as the separate genus Nyholmiella.  相似文献   

6.
Four loaches,Niwaella brevipinna Chen & Chen,sp.nov.,N.fimbriata Chen & Chen,sp.nov.,N.nigrolinea Chen & Chen,sp.nov.and N.qujiangensis Chen &Chen,sp.nov.,are described based on specimens collected from Zhejiang and Anhui Provinces,East China.The mitochondrial cytochrome b gene of 28 individuals of seven species from seven locations collected from Zhejiang,Anhui and Jiangxi Provinces were amplified and analyzed.Morphological and molecular data showed that N.fimbriata Chen & Chen,sp.nov.and N.nigrolinea Chen & Chen,sp.nov.,N.brevipinna Chen& Chen,sp.nov.and N.laterimaculata (Yan & Zheng),N.qujiangensis Chen & Chen,sp.nov.and N.longibarba Chen & Chen are closely related.The seven Chinese Niwaella species,N.brevipinna Chen & Chen,sp.nov.,N.fimbriata Chen & Chen,sp.nov.,N.laterimaculata,N.longibarba,N.nigrolinea Chen & Chen,sp.nov.,N.qujiangensis Chen & Chen,sp.nov.,and N.xinjiangensis are clearly distinguished by the combination of the color patter,mental lobes,suborbital spine,caudal peduncle,body shape,and subdorsal scales.  相似文献   

7.
《Ostrich》2013,84(3):261-266
We used a 298?bp fragment of the mitochondrial cytochrome c oxidase subunit I gene (COI) to examine sequence variation in (mostly) museum specimens of the African Goshawk Accipiter tachiro. Our results showed two clades with high bootstrap support in a phylogenetic analysis and two groups in a nonmetric multidimensional scaling (NMDS) analysis. Each of the two phylogenetic clades corresponded to one of the NMDS groups. One clade comprised haplotypes of the subspecies A. t. lopezi, A. t. macroscelides, A. t. toussenelli and A. t. canescens and corresponded to the morphospecies A. toussenelii. This taxon has a more north-western distribution. The second clade comprised haplotypes of the subspecies A. t. sparsimfasciatus, A. t. pembaensis and A. t. tachiro and corresponded to the morphospecies A. tachiro, which has a more south-eastern distribution. Furthermore, one branch corresponded to the morphospecies A. t. unduliventer, which is confined to the Ethiopian highlands. The genetic divergence observed among the three A. tachiro morphospecies appeared concordant with the ecological and morphological divergence and suggests the existence of three putative species. Within A. tachiro and A. toussenelii there is substantial morphological, but very little genetic, differentiation among subspecies.  相似文献   

8.
Albinaria (Gastropoda, Clausiliidae) is a pulmonate genus distributed around the north-eastern coasts of the Mediterranean. It is the most 'speciose' genus within the family of Clausiliidae, exhibiting a high degree of morphological and genetic differentiation, and serving as a model for several ecological, systematics and evolutionary studies. Nevertheless, many aspects remain uncertain mainly due to the large number of taxa whose classification has not yet been evaluated with solid synapomorphic characters. Thirty-one morphological species are currently recognized on the island of Crete and its satellite islets. Four of them (A. retusa, A. torticollis, A. jaeckeli, and A. teres) are distributed on the island of Dia (north of Crete); the first three are island endemics. Here, we combined mitochondrial and nuclear DNA information and Bayesian and Maximum Likelihood approaches to evaluate the phylogenetic relationships, and assess the genetic distinctiveness and cohesiveness of all described species of Dia Island. The produced phylogeny was not congruent with the morphological species, demonstrating a more complex pattern of speciation and diversification. Although each island endemic constitutes a monophyletic lineage, the number of island endemic species could be greater than the three currently recognized species so far (A. retusa, A. torticollis, and A. jaeckeli), since a newly discovered lineage (north-western part of the island), that morphologically differs from the populations of A. torticollis in the eastern part, and genetically is more closely related to A. jaeckeli, could be elevated to the species level. Considering the fourth species found on the island of Dia, A. teres is genetically highly variable, showing low geographic structuring due to either long-distance gene flow or retained ancestral polymorphisms, or a combination of both. Further work (analysis of more specimens and DNA data) both from Dia and Crete is indispensable in order to shed light on aspects of the evolutionary history of the genus in Dia.  相似文献   

9.
Halosarpheia unicellularis sp. nov. is described from decayed attached wood ofAvicennia marina collected from two mangrove sites in the Red Sea, Egypt. The ascomycete is compared with other marine taxa having ascospores with polar unfurling appendages. It is also compared with other marine genera with oval, round or ellipsoid hyaline, unicellular ascospores, but for which appendages have not been reported. Molecular data confirms the assignment of the fungus toHalosarpheia which forms a clade with the type speciesHalosarpheia fibrosa.  相似文献   

10.
The first comprehensive overview of intra‐ and interspecific variation within the genus Corvus as well as first insights into the phylogenetic relationships of its species is presented. DNA sequences of the mitochondrial control region were obtained from 34 of the 40 described species (including subspecies: 56 taxa). As the study was based mainly on museum material, several specimens did not yield the full length marker sequence. In these cases, only a short section of the control region could be analysed. Nevertheless, even these individuals could be assigned tentatively to clades established on the full length marker sequence. Inclusion of sequences of other corvid genera as available in GenBank clearly confirmed the monophyly of the genus Corvus. Within the Corvus clade several distinct subclades can be distinguished. Some represent lineages of single species or species pairs while other clades are composed of many species. In general, the composition of the clades reflects geographical contiguousness and confirms earlier assumptions of a Palearctic origin of the genus Corvus with several independent colonizations of the Nearctic and the Aethiopis. The Australasian radiation seems to be derived from a single lineage. The distribution of plumage colour in the phylogenetic tree indicates that the pale markings evolved several times independently. The white/grey plumage colour pattern – which is found also in other genera of the family Corvidae, for example, in Pica– occurs already in the species pair representing the first split within the genus Corvus (Corvus monedula, Corvus dauuricus). Thus, reversal to full black colour seems to have occurred as well. The use of colour traits as a phylogenetic marker within Corvus should be considered with severe caution.  相似文献   

11.
12.
A critical reassessment of the morphological features of two closely related red algal genera,Grateloupia C.Agardh and Sinotubimorpha W.X.Li & Z.F.Ding (Halymeniaceae),pointed out that members of the t...  相似文献   

13.
A molecular phylogeny based on DNA/DNA hybridization revealed that the Sylvia-Parisoma complex is monophyletic and includes three main groups of species, the “mid-European” warblers, the genus Parisoma, and the “eu-Mediterranean” Sylvia species sensu stricto. The latter can be assigned to three main clusters, a “West-Mediterranean” group, a “Central-Mediterranean group”, and an “East-Mediterranean” group. The radiation of the whole complex is much more ancient than formerly believed. It started ca 12–13 Ma ago and the ancestors of the main extant groups differentiated during the Pliocene. Only speciation events within the “eu-Mediterranean” lineages occurred during the Pleistocene. The paleoclimatical and paleoecological history of the Mediterranean region is too complicated to provide any evidence for direct relationships between past events and evolutionary steps of these taxa which did not leave any reliable fossil record. However, some major speciation events may be related to well documented climatical crises as well as paleobotanical data. The largely man-induced extension of matorrals over several millenia presumably extended the range of several species that were formerly much more restricted, which complicates reconstruction of the spatio-temporal course of speciation.  相似文献   

14.
Plotopterids (Aves: Plotopteridae) are extinct wing-propelled diving birds which exhibit a strikingly similar wing morphology to penguins (Spheniscidae), but also share derived characters with 'pelecaniform' birds that are absent in penguins. The similarities between Plotopteridae and Spheniscidae have hitherto been attributed to convergence, and plotopterids were considered to be most closely related to the 'pelecaniform' Phalacrocoracidae (cormorants) and Anhingidae (anhingas). However, here I show that assignment of plotopterids to 'pelecaniform' birds does not necessarily preclude them from being the sister taxon of penguins. Cladistic analysis of 68 morphological characters resulted in sister group relationship between Plotopteridae and Spheniscidae, and the clade (Plotopteridae + Spheniscidae) was shown to be the sister taxon of the Suloidea, i.e. a clade including Sulidae (boobies and gannets), Phalacrocoracidae, and Anhingidae. Derived characters are discussed which support this novel hypothesis. Paedomorphosis probably accounts for the absence of derived characters in penguins that are shared by Plotopteridae and members of the Steganopodes. Plotopterids exemplify the importance of fossil birds for analyzing the phylogenetic relationships of modern taxa that exhibit a highly apomorphic morphology.  相似文献   

15.
Mitochondrial DNA sequences of approximately 1.5 kbp including the NADH dehydrogenase subunit 2 (ND2) gene and its flanking gene regions were determined for 20 species from the freshwater fish family Channidae and 3 species from Nandidae, Badidae, and Osphronemidae. Channa orientalis and C. gachua had an approximately 170-bp insertion between the tRNAMet and ND2 genes, where a 5′-half of the insertion was similar to the 5′-end portion of the ND2 gene and a 3′-half was homologous to the tRNAMet gene. This insertion may thus have originated from a tandem gene duplication that occurred in a common ancestor of these two sister species. Molecular phylogenetic analyses from different tree-building methods consistently suggested the mutual monophyly of the African and Asian taxa and the existence of several clades within the Asian taxa, some of which correspond to distinct morphological features. Our molecular phylogeny clearly supported multiple independent losses of pelvic fins on Asian lineages in parallel. Divergence time estimation based on some reasonable assumptions without assuming the molecular clock suggested the early Cretaceous divergence of the African and Asian channids. The results thus support an ancient vicariant divergence of the African and Asian channids, rather than the more recent dispersal between African and Eurasian continents.  相似文献   

16.
Molecular phylogenetic studies are very scarce for the Mugilidae family; the present analysis using DNA sequences of the mitochondrial 16S rRNA and cytochrome b genes is the first study involving Brazilian mugilids. The results corroborate the monophyly of Mugil and are elucidative for the taxonomy of Brazilian mugilids. Mugil curema is clearly divided into two genetically distinct taxa, M. curema type I being closer related to Mugil hospes and the true M. curema (type II) grouping significantly with M. incilis. The results also suggest that Mugil liza and Mugil platanus should be treated as a single species or even populations of Mugil cephalus.  相似文献   

17.
A new genus and species of octocoral with a calcium-carbonate skeleton, Nanipora kamurai sp. n., is described from a shallow coral reef in Okinawa, Japan. Contrary to most octocorals, the skeleton is composed of crystalline aragonite as in blue coral Heliopora. The results of molecular phylogenetic analyses of sequences of mtMutS, COI, and ITS1-5.8s-ITS2-28S region suggest Nanipora gen. n. specimens should be included in order Helioporacea. Based on morphological results compared with other Helioporacea including the genus Epiphaxum (family Lithotelestidae), we establish the new genus Nanipora within Lithotelestidae. This is the first time that a close molecular phylogenetic relationship between Heliopora and a related genus within Helioporacea has been revealed.  相似文献   

18.
Klasea , traditionally treated as a section in Serratula , is now widely accepted at the generic level. A classification of the genus is presented here, accommodating the 46 species in ten sections based on nuclear ribosomal DNA external and internal transcribed spacer sequence data and morphology. New combinations for five species and ten subspecies are published, and a new hybrid species is described. The genus ranges from the Iberian Peninsula and north Africa through southern and eastern Europe, west and central Asia to the Himalayas, and the Far East of Russia and China. The ancestral area is in west Asia, most probably eastern Anatolia and northern and western Iran. In this region, representatives of all sections are present. The largest section Klasea diversified most likely in the mountains of central Asia. A key to all Klasea species is provided.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 435–464.  相似文献   

19.
Scolytoplatypodini Blandford is a monotypic tribe of ambrosia beetles found in Asia, Madagascar and Africa. Only three species are currently known from Madagascar and four additional species are here described as new to science. Phylogenetic analyses of morphological and molecular data revealed that four of the seven endemic species are deeply separated from all other species by genetic and distinct morphological characters and therefore placed in a new genus Remansus Jordal. The split between this ancient lineage and Scolytoplatypus Schaufuss was estimated to approximate Palaeocene age (63 Ma), extending the minimum age of ambrosia feeding for this tribe to the beginning of the Palaeocene‒Eocene thermal maximum (PETM). In addition to the ancient origin of Remansus in Madagascar during the Palaeocene, a second origin occurred in Scolytoplatypus no more than 13 Ma. A geographical origin of the latter in South-Eastern Africa was unequivocally inferred from the phylogenies.  相似文献   

20.
Phylogeny, evolution, and taxonomy of vannellid amoebae   总被引:1,自引:0,他引:1  
We sequenced 18S rRNA genes from 21 vannellid amoebae (Amoebozoa; Vannellidae), including nearly all available type cultures, and performed a comprehensive phylogenetic analysis for 57 Vannellidae sequences. The results show that species of Vannella and Platyamoeba are completely mixed and do not form distinct clades. Several very closely related species pairs exist, each with a Vannella and a Platyamoeba species differing in only a few nucleotides. Therefore, presence (Vannella) or absence (Platyamoeba) of glycostyles in the cell surface coat is an invalid generic distinction; the genera must be merged. As Vannella has priority, we formally transferred Platyamoeba species into Vannella, except for the non-vannellid P. stenopodia, here renamed Stenamoeba stenopodia gen. n. comb. n. and transferred to the family Thecamoebidae. Our trees show that Vannella glycostyles were probably easily and repeatedly evolutionarily lost. We have established a new genus Ripella, with distinct morphology and sequence signatures for Vannella platypodia and morphologically similar species that form a clearly separate clade, very distant from other Vannellidae. Vannellids form four well-separated single-genus clades: Vannella sensu stricto, Ripella, Clydonella, and Lingulamoeba. Species of the revised genus Vannella comprise four closely related, well-supported subclades: one marine and three freshwater. Here, we provide an illustrated checklist for all 40 known Vannellidae species.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号