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1.
The family Labridae (including scarines and odacines) contains 82 genera and about 600 species of fishes that inhabit coastal and continental shelf waters in tropical and temperate oceans throughout the world. The Labridae (the wrasses) is the fifth largest fish family and second largest marine fish family, and is one of the most morphologically and ecologically diversified families of fishes in size, shape, and color. Labrid phylogeny is a long-standing problem in ichthyology that is part of the larger question of relationships within the suborder Labroidei. A phylogenetic analysis of labrids was conducted to investigate relationships among the six classical tribes of wrasses, the affinities of the wrasses to the parrotfishes (scarines), and the broad phylogenetic structure among labrid genera. Four gene fragments were sequenced from 98 fish species, including 84 labrid fishes and 14 outgroup taxa. Taxa were chosen from all major labrid clades and most major global ocean regions where labrid fishes exist, as well as cichlid, pomacentrid, and embiotocid outgroups. From the mitochondrial genome we sequenced portions of 12S rRNA (1000 bp) and 16S rRNA (585 bp), which were aligned by using a secondary structure model. From the nuclear genome, we sequenced part of the protein-coding genes RAG2 (846 bp) and Tmo4C4 (541 bp). Maximum likelihood, maximum parsimony, and Bayesian analyses on the resulting 2972 bp of DNA sequence produced similar topologies that confirm the monophyly of a family Labridae that includes the parrotfishes and butterfishes and strong support for many previously identified taxonomic subgroups. The tribe Hypsigenyini (hogfishes, tuskfishes) is the sister group to the remaining labrids and includes odacines and the chisel-tooth wrasse Pseudodax moluccanus, a species previously considered close to scarines. Cheilines and scarines are sister-groups, closely related to the temperate Labrini, and pseudocheilines and cheilines are split in all phylogenies. The razorfishes (novaculines) and temperate pseudolabrines form successive sister clades to the large crown group radiation of the Julidini. The cleaner wrasses (Labrichthyini) are nested within this radiation and several julidine genera do not appear to be monophyletic (e.g., Coris and Halichoeres). Invasion of temperate water by this predominantly tropical group has occurred multiple times and the reconstruction of biogeography assuming an Indo-Pacific ancestor results in five different lineages invading the Atlantic/Caribbean region. Functional novelties in the feeding apparatus have allowed labrid fishes to occupy nearly every feeding guild in reef environments, and trophic variation is a central axis of diversification in this family.  相似文献   

2.
The family Labridae is a large assemblage of marine fish composed of about 580 species in 82 genera distributed in tropical and temperate marine waters around the world. Several subgroups, currently classified as tribes, have been identified in this large family, yet only a few phylogenetic analyses have been performed on labrid clades. We confirm monophyly of the labrid tribe Labrini and propose a phylogeny of the 23 species of the genera Acantholabrus, Centrolabras, Ctenolabrus, Labrus, Lappanella, Symphodus, Tautoga, and Tautogolabrus occurring in the eastern and western Atlantic and the Mediterranean. We analyzed a 577-bp segment of the mitochondrial 16S rDNA and a 506-bp segment of the mitochondrial control region in 22 species, for a total of up to 1069 bp per species. We used both parsimony and likelihood approaches under a variety of assumptions and models to generate phylogenetic hypotheses. The main features of the molecular phylogeny for the Labrini turned out to be the same for the two algorithms applied. The tree structure is similar to a previous, unpublished morphological phylogeny for a subset of labrine species. Estimated divergence times of the Labrini based on fossils and a molecular clock range from about 15 mya for the deepest splits to less than 1 mya for younger clades. Biogeographic patterns of the Symphodus species group and the genus Labrus are dominated by speciation events driven by the closing and opening of the Mediterranean Sea and periodic glaciation events during the past 1 million years. The Labrini are the only clade in the entire Labridae that exhibit nest-building and broodcare behavior. We use the phylogeny to show that similar broodcare behavior has evolved twice in the labrine fish and discuss scenarios for the evolution of broodcare from the diandric protogynous hermaphroditism found in ancestral labrines and many other wrasses.  相似文献   

3.
We newly sequenced the nuclear-encoded small subunit (SSU) rDNA coding region for 21 taxa of the genus Closterium. The new sequences were integrated into an alignment with 13 known sequences of conjugating green algae representing six traditional families (i.e. Zygnemataceae, Mesotaeniaceae, Gonatozygaceae, Peniaceae, Closteriaceae, and Desmidiaceae) and five known charophycean sequences as outgroups. Both maximum likelihood and maximum parsimony analyses supported with high bootstrap values one large clade containing all placoderm desmids (Desmidiales). All the Closterium taxa formed one clade with 100% bootstrap support, indicating their monophyly, but not paraphyly, as suggested earlier. As to the taxa within the genus Closterium , we found two clades of morphologically closely related taxa in both maximum likelihood and maximum parsimony trees. They corresponded to the C. calosporum species complex and the C. moniliferum-ehrenbergii species complex. It is of particular interest that the homothallic entity of C. moniliferum v. moniliferum was distinguished from and ancestral to all other entities of the C. moniliferum-ehrenbergii species complex. Superimposing all 50 charophycean sequences on the higher order SSU rRNA structure model of Closterium , we investigated degrees of nucleotide conservation at a given position in the nucleotide sequence. A characteristic "signature" structure to the genus Closterium was found as an additional helix at the tip of V1 region. In addition, eight base deletions at the tip of helix 10 were found to be characteristic of the C. calosporum species complex, C. gracile , C. incurvum , C. pleurodermatum , and C. pusillum v. maius. These taxa formed one clade with an 82% bootstrap value in maximum parsimony analysis.  相似文献   

4.
5.
Nucleotide sequences from four chloroplast genes, the matK, chlL, intergenic spacer (IGS) region between trnL and trnF, and an intron of trnL, were determined from all species of Taxodiaceae and five species of Cupressaceae sensu stricto (s.s.). Phylogenetic trees were constructed using the maximum parsimony and the neighbor-joining methods with Cunninghamia as an outgroup. These analyses provided greater resolution of relationships among genera and higher bootstrap supports for clades compared to previous analyses. Results indicate that Taiwania diverged first, and then Athrotaxis diverged from the remaining genera. Metasequoia, Sequoia, and Sequoiadendron form a clade. Taxodium and Glyptostrobus form a clade, which is the sister to Cryptomeria. Cupressaceae s.s. are derived from within Taxodiaceae, being the most closely related to the Cryptomeria/Taxodium/Glyptostrobus clade. These relationships are consistent with previous morphological groupings and the analyses of molecular data. In addition, we found acceleration of evolutionary rates in Cupressaceae s.s. Possible causes for the acceleration are discussed.  相似文献   

6.
The first comprehensive phylogenetic analyses of the most diverse subfamily of plant bugs, Mirinae, is presented in this study, for 110 representative taxa based on total evidence analysis. A total of 85 morphological characters and 3898 bp of mitochondrial (16S, COI) and nuclear (18S, 28S) sequences were analysed for each partitioned and combined dataset based on parsimony, maximum likelihood and Bayesian inference. Major results obtained in this study include monophyly of the tribe Mecistoscelini. The largest tribe, Mirini, was recovered as polyphyletic, and Stenodemini was recovered as paraphyletic. The clade of Stenodemini + Mecistoscelini is the sister group of the remaining Mirinae. The monophyly of two complexes composed of superficially similar genera were tested; the Lygus complex was recovered as nonmonophyletic, and the Adelphocoris–Creontiades–Megacoelum complex was confirmed to be monophyletic. The generic relationships of the main clades within each tribe based on the phylogeny, as well as their supported morphological characters, are discussed.  相似文献   

7.
A molecular phylogenetic analysis of the "true thrushes" (Aves: Turdinae)   总被引:2,自引:0,他引:2  
The true thrushes (Passeriformes: Muscicapidae, subfamily Turdinae) are a speciose and widespread avian lineage presumed to be of Old World origin. Phylogenetic relationships within this assemblage were investigated using mitochondrial DNA (mtDNA) sequence data that included the cytochrome b and ND2 genes. Our ingroup sampling included 54 species representing 17 of 20 putative turdine genera. Phylogenetic trees derived via maximum parsimony and maximum likelihood were largely congruent. Most of the Turdine taxa sampled can be placed into one of six well supported clades. Our data indicate a polyphyletic Zoothera which can be divided into at least two (Afro-Asian and Austral-Asian) main clades. The genus Turdus, as presently recognized, is paraphyletic but forms a well supported clade with the addition of three mostly monotypic genera (Platycichla, Nesocichla, and Cichlherminia). We identify an exclusively New World clade that includes a monophyletic Catharus, Hylocichla, Cichlopsis, Entomodestes, Ridgwayia, and Ixoreus. Members of the morphologically and behaviorally distinct genera Sialia, Myadestes, and Neocossyphus unexpectedly form a basal clade. Using multiple outgroup choices, we show that this group is distantly related, but unequivocally the sister group to the remaining Turdines sampled. The Turdinae appear to be a relatively old songbird lineage, originating in the mid to late Miocene. If the Turdinae are indeed Old World in origin, our data indicate a minimum of three separate invasions of the New World.  相似文献   

8.
A phylogenetic analysis of 25 species, representing eight genera of theRubieae tribe (Rubiaceae), has been made using the DNA sequence of the chloroplastatp B-rbc L intergene region. Six tropical genera from other tribes ofRubiaceae have been used as outgroups. Whatever the method of analysis (distance, parsimony or maximum likelihood), five groups are clearly separated and described as informal clades. Their relative relationships are not clearly resolved by the parsimony analysis, resulting in eight equally parsimonious trees, 327 steps long, with a consistency index (CI) of 0.749 (excluding uninformative sites). TheRubieae tribe appears monophyletic from the data available. Some new and partly unexpected phylogenetic relationships are suggested. The genusRubia forms a separate clade and appears to be the relatively advanced sister group of the remaining taxa. TheSherardia clade also includes the generaCrucianella andPhuopsis. Galium sect.Aparinoides appears closely attached to theAsperula sect.Glabella clade. The remaining taxa ofGalium are paraphyletic:Galium sect.Platygalium (in theCruciata clade) is linked to the advanced generaCruciata andValantia; the more apomorphic groups ofGalium form theGalium sect.Galium clade, including the perennial sectionsGalium, Leiogalium, andLeptogalium as well as the annual (and possibly polyphyletic) sect.Kolgyda.  相似文献   

9.
基于两个叶绿体基因(matK和rbcL)和一个核糖体基因(18S rDNA)的序列分析,对代表了基部被子植物和单子叶植物主要谱系分支的86科126属151种被子植物(单子叶植物58科86属101种)进行了系统演化关系分析。研究结果表明由胡椒目Piperales、樟目Laurales、木兰目Magnoliales和林仙目Canellales构成的真木兰类复合群是单子叶植物的姐妹群。单子叶植物的单系性在3个序列联合分析中得到98%的强烈自展支持。联合分析鉴定出9个单子叶植物主要谱系(广义泽泻目Alismatales、薯蓣目Dioscorcales、露兜树目Pandanales、天门冬目Asparagalcs、百合目Liliales、棕榈目Arecales、禾本目Poales、姜目Zingiberales、鸭跖草目Commelinales)和6个其他被子植物主要谱系(睡莲目Nymphaeales、真双子叶植物、木兰目、樟目、胡椒目、林仙目)。在单子叶植物内,菖蒲目Acorales(菖蒲属Acorus)是单子叶植物最早分化的一个谱系,广义泽泻目(包括天南星科Araceae和岩菖蒲科Toficldiaccae)紧随其后分化出来,二者依次和其余单子叶植物类群构成姐妹群关系。无叶莲科Petrosaviaceac紧随广义的泽泻目之后分化出来,无叶莲科和剩余的单子叶植物类群形成姐妹群关系,并得到了较高的支持率。继无叶莲科之后分化的类群形成两个大的分支:一支是由露兜树目和薯蓣目构成,二者形成姐妹群关系:另一支是由天门冬目、百合目和鸭跖草类复合群组成,三者之间的关系在单个序列分析和联合分析中不稳定,需要进一步扩大取样范围来确定。在鸭跖草类复合群分支内,鸭跖草目和姜目的姐妹群关系在3个序列联合分析和2个序列联合分析的严格一致树中均得到强烈的自展支持,获得的支持率均是100%。但是,对于棕榈目和禾本目在鸭跖草类中的系统位置以及它们和鸭跖草目-姜目之间的关系,有待进一步解决。值得注意的是,无叶莲科与其他单子叶植物类群(除菖蒲目和泽泻目外)的系统关系在本文中获得较高的自展支持率,薯蓣目和天门冬目的单系性在序列联合分析中都得到了较好的自展支持,而这些在以往的研究中通常支持率较低。鉴于菖蒲科和无叶莲科独特的系统演化位置,本文支持将其分别独立成菖蒲目和无叶莲目Petrosavialcs的分类学界定。  相似文献   

10.
Members of subfamily Gronovioideae are distinctive among Loasaceae in their androecial and gynoecial simplicity. The four genera of the subfamily differ, however, in chromosome number, floral novelties, and pollen exine sculpturing, which led to suggestions that the Gronovioideae were polyphyletic. Phylogenetic analyses based on sequences of the chloroplast gene matK and the internal transcribed spacer region (ITS) of nuclear rDNA have been conducted using parsimony and maximum likelihood methods to assess the monophyly of Gronovioideae and to determine the sister group relationships of gronovioid genera. The results show Gronovioideae are monophyletic and placed as the sister to Mentzelia. Within Gronovioideae, Petalonyx is sister to a clade consisting of Cevallia, Gronovia, and Fuertesia. Among the remaining Loasaceae, subfamily Mentzelioideae, as originally circumscribed, is paraphyletic. Subfamily Loasoideae is placed as the sister to the Gronovioideae-Mentzelia clade.  相似文献   

11.
Phylogenetic relationships of the subfamily Combretoideae (Combretaceae) were studied based on DNA sequences of nuclear ribosomal internal transcribed spacer (ITS) regions, the plastid rbcL gene and the intergenic spacer between the psaA and ycf3 genes (PY-IGS), including 16 species of eight genera within two traditional tribes of Combretoideae, and two species of the subfamily Strephonematoideae of Combretaceae as outgroups. Phylogenetic trees based on the three data sets (ITS, rbcL, and PY-IGS) were generated by using maximum parsimony (MP) and maximum likelihood (ML) analyses. Partition-homogeneity tests indicated that the three data sets and the combined data set are homogeneous. In the combined phylogenetic trees, all ingroup taxa are divided into two main clades, which correspond to the two tribes Laguncularieae and Combreteae. In the Laguncularieae clade, two mangrove genera, Lumnitzera and Laguncularia, are shown to be sister taxa. In the tribe Combreteae, two major clades can be classified: one includes three genera Quisqualis, Combretum and Calycopteris, within which the monophyly of the tribe Combreteae sensu Engler and Diels including Quisqualis and Combretum is strongly supported, and this monophyly is then sister to the monotypic genus Calycopteris; another major clade includes three genera Anogeissus, Terminalia and Conocarpus. There is no support for the monophyly of Terminalia as it forms a polytomy with Anogeissus. This clade is sister to Conocarpus. Electronic Publication  相似文献   

12.
The current classification of the Monocotylidae (Monogenea) is based on a phylogeny generated from morphological characters. The present study tests the morphological phylogenetic hypothesis using molecular methods. Sequences from domains C2 and D1 and the partial domains C1 and D2 from the 28S rDNA gene for 26 species of monocotylids from six of the seven subfamilies were used. Trees were generated using maximum parsimony, neighbour joining and maximum likelihood algorithms. The maximum parsimony tree, with branches showing less than 70% bootstrap support collapsed, had a topology identical to that obtained using the maximum likelihood analysis. The neighbour joining tree, with branches showing less than 70% support collapsed, differed only in its placement of Heterocotyle capricornensis as the sister group to the Decacotylinae clade. The molecular tree largely supports the subfamilies established using morphological characters. Differences are primarily how the subfamilies are related to each other. The monophyly of the Calicotylinae and Merizocotylinae and their sister group relationship is supported by high bootstrap values in all three methods, but relationships within the Merizocotylinae are unclear. Merizocotyle is paraphyletic and our data suggest that Mycteronastes and Thaumatocotyle, which were synonymized with Merizocotyle after the morphological cladistic analysis, should perhaps be resurrected as valid genera. The monophyly of the Monocotylinae and Decacotylinae is also supported by high bootstrap values. The Decacotylinae, which was considered previously to be the sister group to the Calicotylinae plus Merizocotylinae, is grouped in an unresolved polychotomy with the Monocotylinae and members of the Heterocotylinae. According to our molecular data, the Heterocotylinae is paraphyletic. Molecular data support a sister group relationship between Troglocephalus rhinobatidis and Neoheterocotyle rhinobatidis to the exclusion of the other species of Neoheterocotyle and recognition of Troglocephalus renders Neoheterocotyle paraphyletic. We propose Troglocephalus incertae sedis. An updated classification and full species list of the Monocotylidae is provided.  相似文献   

13.
测定了分布于中国的锯眼蝶亚科4族10属共20个种的线粒体ND1和COI基因的部分序列,结合从GenBank中获得的4个国外种类的同源序列,以凤蝶科的迪洛尔娟凤蝶(Allancatria deyrolle)、丝带凤蝶(Sericinus montela),以及娟蝶科的西猛娟蝶(Parnassius simonius)为外类群,通过邻接法、最大简约法、最大似然法和贝叶斯法重建了分子系统树,分析了该亚科内主要类群的系统发生关系。分析结果表明:帻眼蝶族和锯眼蝶族具有较近的亲缘关系;黛眼蝶族不是单系群,该族中的黛眼蝶属、荫眼蝶属与眉眼蝶族具有较近的亲缘关系,带眼蝶属、藏眼蝶属、毛眼蝶属和帕眼蝶属聚合为一个独立的支系,其中带眼蝶属和藏眼蝶属在所有的分析方法中均以100%的置信度(BP=100%,PP=1.00)相聚合,建议将它们合并为一属。  相似文献   

14.
基于核基因c-mos的鸫亚科部分鸟类系统发生关系   总被引:1,自引:1,他引:0  
采用分子系统学方法对鸫亚科Turdinae 11属21种鸟类的核基因c-mos进行了系统发生分析.所测序列经对位排列后共572个位点,其中核苷酸变异位点111个,简约信息位点71个.以太平鸟Bombycilla garrulus作外群,采用邻接法、最大简约法和最大似然法分别构建其系统发生树.重建的系统发生树显示:所研究鸫亚科21种鸟类分成2个支系,第1个支系包括鸫属Turdus和地鸫属Zoothera.第2个支系包括红尾鸲属Phoenicurus、矶鸫属Monticola、水鸲属Rhyacornis、鸲属Tarsiger、溪鸲属Chainarrornis、石即鸟属Saxicola、燕尾属Enivurus、歌鸲属Luscinia和鹊鸲属Copsychus.红尾鸲属为并系类群,水鸲属和溪鸲属聚到这一支系;歌鸲属与燕尾属互为姐妹群,再与鸲属聚合构成另一支系;宝兴歌鸫Turdus mupinensis独立于鸫属及地鸫属之外,形成单独一个分支.  相似文献   

15.
The current classification of the Monocotylidae (Monogenea) is based on a phylogeny generated from morphological characters. The present study tests the morphological phylogenetic hypothesis using molecular methods. Sequences from domains C2 and D1 and the partial domains C1 and D2 from the 28S rDNA gene for 26 species of monocotylids from six of the seven subfamilies were used. Trees were generated using maximum parsimony, neighbour joining and maximum likelihood algorithms. The maximum parsimony tree, with branches showing less than 70% bootstrap support collapsed, had a topology identical to that obtained using the maximum likelihood analysis. The neighbour joining tree, with branches showing less than 70% support collapsed, differed only in its placement of Heterocotyle capricornensis as the sister group to the Decacotylinae clade. The molecular tree largely supports the subfamilies established using morphological characters. Differences are primarily how the subfamilies are related to each other. The monophyly of the Calicotylinae and Merizocotylinae and their sister group relationship is supported by high bootstrap values in all three methods, but relationships within the Merizocotylinae are unclear. Merizocotyle is paraphyletic and our data suggest that Mycteronastes and Thaumatocotyle, which were synonymized with Merizocotyle after the morphological cladistic analysis, should perhaps be resurrected as valid genera. The monophyly of the Monocotylinae and Decacotylinae is also supported by high bootstrap values. The Decacotylinae, which was considered previously to be the sister group to the Calicotylinae plus Merizocotylinae, is grouped in an unresolved polychotomy with the Monocotylinae and members of the Heterocotylinae. According to our molecular data, the Heterocotylinae is paraphyletic. Molecular data support a sister group relationship between Troglocephalus rhinobatidis and Neoheterocotyle rhinobatidis to the exclusion of the other species of Neoheterocotyle and recognition of Troglocephalus renders Neoheterocotyle paraphyletic. We propose Troglocephalus incertae sedis. An updated classification and full species list of the Monocotylidae is provided.  相似文献   

16.
The 14 species of Crambe L. sect. Dendrocrambe DC. (Brassicaceae) form a monophyletic group endemic to the Canary and Madeira archipelagos. Both parsimony and maximum likelihood analyses of sequence data from the two internal transcribed spacer regions of nuclear ribosomal DNA were used to estimate phylogenetic relationships within this section. These analyses support the monophyly of three major clades. No clade is restricted to a single island, and therefore it appears that inter-island colonization has been the main avenue for speciation in these two archipelagos. The two species endemic to Fuerteventura (C. sventenii) and Madeira (C. fruticosa) comprise a clade, providing the first evidence for a floristic link between the Eastern Canary Islands and the archipelago of Madeira. Both maximum likelihood and weighted parsimony analyses show that this clade is sister to the two other clades, although bootstrap support for this relationship is weak. Parsimony optimizations of ecological zones and island distribution suggest a colonization route from the low-altitude areas of the lowland scrub toward the high-elevation areas of the laurel and pine forests. In addition, Tenerife is likely the ancestral island for species endemic to the five westernmost islands of Gran Canaria, La Gomera, El Hierro, La Palma, and Tenerife.  相似文献   

17.
Loranthaceae (73 genera and ca. 900 species) comprise mostly aerial hemiparasitic plants. Three monotypic genera considered relicts are root parasites. The family is diverse in tropical areas, but representatives are also found in temperate habitats. Previous classifications were based on floral and inflorescence morphology, karyological information, and biogeography. The family has been divided into three tribes: Nuytsiae, Elytrantheae (subtribes Elytranthinae and Gaiadendrinae), and Lorantheae (subtribes Loranthinae and Psittacanthinae). Nuytsiae and Elytrantheae are characterized by a base chromosome number of x = 12, whereas subtribes Loranthinae (x = 9) and Psittacanthinae (x = 8) numbers are derived via aneuploid reduction. To elucidate the phylogeny of the family, we analyzed sequences from five genes (nuclear small and large subunit rDNA and the chloroplast genes rbcL, matK, and trnL-F) representing most genera using parsimony, likelihood, and Bayesian inference. The three root parasites, Nuytsia, Atkinsonia, and Gaiadendron, are supported as successive sister taxa to the remaining genera, resulting in a monophyletic group of aerial parasites. Three major clades are resolved each corresponding to a subtribe. However, two South American genera (Tristerix and Notanthera) and the New Zealand genus Tupeia, which were previously classified in subtribe Elytranthinae, are weakly supported as part of a clade representing the South American subtribe Psittacanthinae.  相似文献   

18.
The avian genus Turdus is one of the most speciose and widespread of passerine genera. We investigated phylogenetic relationships within this genus using mitochondrial DNA sequence data from the ND3, ND2 and cytochrome b genes. Our sampling of Turdus included 60 of the 65 extant species currently recognized, as well as all four species from three genera previously shown to fall inside Turdus (Platycichla, Nesocichla, and Cichlherminia). Phylogenetic trees based on maximum likelihood and maximum parsimony algorithms were congruent. Most of the Turdus taxa sampled fall into one of four clades: an African clade, a Central American-Caribbean clade, a largely South American clade, and a Eurasian clade. Still other taxa are placed either at the base of Turdus, or as links between clades. In no instance is any continent reciprocally monophyletic for the species distributed on it. A general lack of nodal support near the base of the phylogeny seems related to a rapid intercontinental establishment of the major clades within Turdus very early in the history of the genus. The monotypic genus Psophocichla is distantly related to, but clearly the sister of, Turdus rather than a constituent member of it.  相似文献   

19.
Using sequences from the plastid trnL-F region and nrDNA ITS, we investigated the phylogeny of the fleshy-fruited African tribe Haemantheae of the Amaryllidaceae across 19 species representing all genera of the tribe. ITS and a combined matrix produce the most resolute and well-supported tree with parsimony analysis. Two main clades are resolved, one comprising the monophyletic rhizomatous genera Clivia and Cryptostephanus, and a larger clade that unites Haemanthus and Scadoxus as sister genera to an Apodolirion/Gethyllis subclade. One of four included Gethyllis species, G. lanuginosa, resolves as sister to Apodolirion with ITS. Relationships among the Clivia species are not in agreement with a previous published phylogeny. Biogeographic analysis using the divergence/vicariance method roots the tribe in Eastern South Africa, with several subsequent dispersals to the winter rainfall Western Cape region. Chromosomal change from an ancestral 2n=22 (characteristic of Clivia) is associated with each main clade. Reduction in number has occurred in all but Cryptostephanus, which has 2n=24 chromosomes. Increasing the sampling across all of the species in the tribe will allow a more detailed understanding of the biogeographic patterns inherent in the parsimony topology, which undoubtedly reflect Quaternary climatic changes in Southern Africa.  相似文献   

20.
Phylogenetic relationships of members of the salamander family Salamandridae were examined using complete mitochondrial genomes collected from 42 species representing all 20 salamandrid genera and five outgroup taxa. Weighted maximum parsimony, partitioned maximum likelihood, and partitioned Bayesian approaches all produce an identical, well-resolved phylogeny; most branches are strongly supported with greater than 90% bootstrap values and 1.0 Bayesian posterior probabilities. Our results support recent taxonomic changes in finding the traditional genera Mertensiella, Euproctus, and Triturus to be non-monophyletic species assemblages. We successfully resolved the current polytomy at the base of the salamandrid tree: the Italian newt genus Salamandrina is sister to all remaining salamandrids. Beyond Salamandrina, a clade comprising all remaining newts is separated from a clade containing the true salamanders. Among these newts, the branching orders of well-supported clades are: primitive newts (Echinotriton, Pleurodeles, and Tylototriton), New World newts (Notophthalmus-Taricha), Corsica-Sardinia newts (Euproctus), and modern European newts (Calotriton, Lissotriton, Mesotriton, Neurergus, Ommatotriton, and Triturus) plus modern Asian newts (Cynops, Pachytriton, and Paramesotriton).Two alternative sets of calibration points and two Bayesian dating methods (BEAST and MultiDivTime) were used to estimate timescales for salamandrid evolution. The estimation difference by dating methods is slight and we propose two sets of timescales based on different calibration choices. The two timescales suggest that the initial diversification of extant salamandrids took place in Europe about 97 or 69Ma. North American salamandrids were derived from their European ancestors by dispersal through North Atlantic Land Bridges in the Late Cretaceous ( approximately 69Ma) or Middle Eocene ( approximately 43Ma). Ancestors of Asian salamandrids most probably dispersed to the eastern Asia from Europe, after withdrawal of the Turgai Sea ( approximately 29Ma).  相似文献   

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