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1.
We present a phylogenetic analysis that includes all known species of Agathemera, using as outgroup four species of the genera Heteronemia, Spinonemia, Monticomorpha, and Anisomorpha. Phylogenetic inference was based on three genes, 16S, COI (mitochondrial markers) and H3 (nuclear marker), based on the maximum‐parsimony, maximum‐likelihood and Bayesian inference methods. Our results show that the genus Agathemera is monophyletic; six of its eight species showed phylogenetic support, while the group A. claraziana + A. millepunctata was not resolved. The resulting topology shows two major clades, the first with A. maculafulgens, A. luteola, A. crassa, A. millepunctata, and A. claraziana, and the second including A. grylloidea, A. mesoauriculae, and A. elegans. Species of the first clade have large mesonotal processes and are found mainly east of the Andes, except for A. crassa. Members of the second clade have small or absent mesonotal processes and are distributed mainly to the west of the Andes. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165 , 63–72.  相似文献   

2.
Yunnanopilia longistaminea (W.Z. Li) C.Y. Wu & D.Z. Li, which is a controversial species in Opiliaceae, is treated as a variety of Champereia manillana (Blume) Merrill in the Flora of China and morphological analysis has produced conflicting results regarding its affinity to Melientha and Champereia. To determine the systematic position of Yunnanopilia in Opiliaceae, we selected two nuclear regions (internal transcribed spacer [ITS4‐ITS5] and 18S rDNA) and four chloroplast regions (rbcL, matK, psbAtrnH, and trnStrnG) to test the phylogenetics of the family Opiliaceae using maximum likelihood and Bayesian inference analysis. Morphological characteristics were also examined to clarify the similarities and differences among Y. longistaminea and two closely related species. Agonandra was located at the basal position in the family Opiliaceae; in the large clade including other remaining genera, two main clades were clearly identified and correlated with inflorescence morphological characteristics. All samples of Y. longistaminea formed a clade. Yunnanopilia, Melientha, and Champereia were more closely related than other genera of Opiliaceae. Yunnanopilia longistaminea was sister to M. suavis Pierre and was more closely related to M. suavis than to C. manillana. Morphological analysis also showed that differences in the inflorescences and flowers between Y. longistaminea and M. suavis were substantial enough to warrant the retention of Y. longistaminea in its current genus. Thus, we suggest that the monotypic Yunnanopilia be treated as a distinct genus and that the name Y. longistaminea should be adopted.  相似文献   

3.
Morphological (including ultrastructural) and developmental characters utilized in recent literature are critically reviewed as the basis to reassess the phylogenetic relationships of gastropods. The purpose of this paper is to provide a framework of characters for future studies and a testable phylogenetic hypothesis. This is one of the first attempts to use such characters to assess the relationships of all major clades using parsimony methods. The analysis uses 117 characters and includes 40 taxa, predominantly ‘prosobranchs’. Five outgroup taxa are included, representing four conchiferan groups and Poly-placophora. Of the 117 characters reviewed and included in the analyses, nine are shell characters (four of these are shell structure), two opercular, two muscular, four ctenidial, 12 renopericardial and 24 reproductive (including 17 based on sperm and spermatogenesis), 27 of the digestive system, 32 of the nervous system and sense organs; the remainder are developmental (3) and of the foot and hypobranchial gland. In the initial analysis the data set included a mixture of binary and multistate characters with all characters unordered. These data were also analysed after scaling so that each character had equal weight. A third data set was constructed in which all characters were coded as binary characters. These analyses resulted in some implausible character transformations, mainly-involving the regaining of lost pallial structures. Additional analyses were run on all three sets of data after removing five characters showing the most unlikely transformations. These analyses resulted in generally similar topologies. The robustness of the clades was tested using clade decay. The adaptive radiation of gastropods and their life history traits are briefly described and discussed and the terminology for simultaneous hermaphroditism refined. A scenario for the evolution of torsion equated with the fossil record is proposed and the effects of torsion and coiling on gastropods are discussed along with asymmetry imposed by limpet-shaped body forms. It is suggested that the first gastropods were ultradextral. The idea that heterochrony has played a major part in gastropod evolution is developed and discussed, particularly the paedomorphic stamp imposed on the apogastropods. The veliger larvae of caenogastropods and heterobranchs are contrasted and found to differ in many respects. The evolution of planktotrophy within gastropods is discussed. Recent phylogenetic hypotheses for gastropods based on molecular data are generally in broad agreement with the present results. On the basis of our analyses we discuss the major monophyletic groups within gastropods. Gastropods appear to be a monophyletic clade, and divide into two primary groups, the Eogastropoda (incorporating the patellogastropods and their (probably sinistrally coiled) ancestors and the Orthogastropoda – the remainder of the gastropods. Orthogastropoda comprises several well defined clades. The vetigastropod clade encompasses most of the groups previously included in the paraphyletic Archaeogastropoda (fissurellids, trochoideans, scissurelloideans, halioroideans pleurotomarioideans) as well as lepeto-driloidean and lepetelloidean limpets and seguenzids. The location of the hot vent taxa Peltospiridae and Neomphalidae varies with each analysis, probably because there is a lack of ultrastructural data for these taxa and parallelism in many characters. They either form a paraphyletic or monophyletic group at or near the base of the vetigastropods or a clade with the neritopsines and cocculinoideans. The neritopsines (Neritoidea etc.) consistently form a clade with the cocculinoidean limpets, but their position on the tree also differs depending on the data set used and (in the case of the scaled data) whether or not the full suite of characters is used. They are either the sister to the rest of the orthogastropods or to the apogastropods. Caenogastropods [Mesogastropoda (+ architaenioglossan groups) + Neogastropoda] are consistently monophyletic as are the heterobranchs (‘Heterostropha’+ Opisthobranchia + Pulmo-nata). The caenogastropods and heterobranchs also form a clade in all the analyses and the name Apogastropoda is redefined to encompass this group. New taxa are proposed, Sorbeoconcha for the caenogastropods exclusive of the architaenioglossan taxa, and Hypsogastropoda for the ‘higher caenogastropods“– the Sorbeoconcha exclusive of the Cerithioidea and Campaniloidea.  相似文献   

4.
Phylogenetic regression is frequently used in macroevolutionary studies, and its statistical properties have been thoroughly investigated. By contrast, phylogenetic ANOVA has received relatively less attention, and the conditions leading to incorrect statistical and biological inferences when comparing multivariate phenotypes among groups remain underexplored. Here, we propose a refined method of randomizing residuals in a permutation procedure (RRPP) for evaluating phenotypic differences among groups while conditioning the data on the phylogeny. We show that RRPP displays appropriate statistical properties for both phylogenetic ANOVA and regression models, and for univariate and multivariate datasets. For ANOVA, we find that RRPP exhibits higher statistical power than methods utilizing phylogenetic simulation. Additionally, we investigate how group dispersion across the phylogeny affects inferences, and reveal that highly aggregated groups generate strong and significant correlations with the phylogeny, which reduce statistical power and subsequently affect biological interpretations. We discuss the broader implications of this phylogenetic group aggregation, and its relation to challenges encountered with other comparative methods where one or a few transitions in discrete traits are observed on the phylogeny. Finally, we recommend that phylogenetic comparative studies of continuous trait data use RRPP for assessing the significance of indicator variables as sources of trait variation.  相似文献   

5.
6.
Previous molecular phylogenetic analyses of the family Cyperaceae based on rbcL sequences showed Bulbostylis as paraphyletic, with B. atrosanguinea and B. hispidula forming a clade with Nemum spadiceum. On the contrary, phylogenetic analyses of the tribe Abildgaardieae based on nuclear (ITS ribosomal region) and plastid sequences (trnL-F region) showed Bulbostylis as monophyletic, although they only incorporated four species of Bulbostylis and none of Nemum. In this work, we presented a phylogenetic hypothesis of Bulbostylis based on a comprehensive sampling, including species from different continents for the first time. New sequences of Abildgaardia, Crosslandia, Fimbristylis, and Nemum were included to test the monophyly of Bulbostylis. In total, 84 sequences of both ITS and trnL regions were generated. Analyses were performed using Bayesian inference, maximum likelihood, and parsimony. Ancestral state reconstruction was performed using ML, MCMC, and parsimony methods. In all analyses, Bulbostylis resulted paraphyletic as Nemum atracuminatum is nested within it. Most American species of Bulbostylis grouped together, but relationships amongst them appeared poorly resolved. Ancestral state reconstructions of native distribution suggest an African ancestor of Bulbostylis, with at least three introduction independent events of the species in America. Morphological diagnostic characters such as the ‘style base permanence or detachment from the ripe achene’, and the ‘micromorphological patterns of the achene surface’ are homoplastic in this phylogenetic context, and therefore unsuitable to propose infrageneric groupings within the Bulbostylis.  相似文献   

7.
Evolution of genes and taxa: a primer   总被引:10,自引:0,他引:10  
The rapidly growing fields of molecular evolution and systematics have much to offer to molecular biology, but like any field have their own repertoire of terms and concepts. Homology, for example, is a central theme in evolutionary biology whose definition is complex and often controversial. Homology extends to multigene families, where the distinction between orthology and paralogy is key. Nucleotide sequence alignment is also a homology issue, and is a key stage in any evolutionary analysis of sequence data. Models based on our understanding of the processes of nucleotide substitution are used both in the estimation of the number of evolutionary changes between aligned sequences and in phylogeny reconstruction from sequence data. The three common methods of phylogeny reconstruction – parsimony, distance and maximum likelihood – differ in their use of these models. All three face similar problems in finding optimal – and reliable – solutions among the vast number of possible trees. Moreover, even optimal trees for a given gene may not reflect the relationships of the organisms from which the gene was sampled. Knowledge of how genes evolve and at what rate is critical for understanding gene function across species or within gene families. The Neutral Theory of Molecular Evolution serves as the null model of molecular evolution and plays a central role in data analysis. Three areas in which the Neutral Theory plays a vital role are: interpreting ratios of nonsynonymous to synonymous nucleotide substitutions, assessing the reliability of molecular clocks, and providing a foundation for molecular population genetics.  相似文献   

8.
In order to understand the natural situation of rickettsiae in the ticks in Japan, the rickettsial genes, gltA gene, rOmpA gene, and 17-kDa gene, were amplified from the ticks by nested PCR. The prevalences of rickettsial gltA genes among Haemaphysalis formosensis, H. longicornis, H. megaspinosa, Ixodes ovatus, H. flava, H. kitaokai, and I. persulcatus were 62, 57, 24, 24, 19, 13, and 10%, respectively; 26% (186/722) being the average. The gltA genes amplified from the ticks were classified into 9 genotypes (I to IX) by the difference in nucleotide sequences. Genotype I was detected from 7 species of ticks. Genotype II mainly was detected from H. longicornis and H. formosensis. Genotypes III and VII mainly were detected from H. flava and I. ovatus. The polarization in the distribution of genotypes among regions where the ticks were collected was not clear. Based on the phylogenetic analysis of the three genes presented here, genotypes I, III, and IV (detected from H. formosensis, H. hystricia, and I. ovatus ) are genetically close with each other, but rickettsiae of the same property still have not been isolated from ticks anywhere in the world. These genotypes should be considered as new species among SFG rickettsiae. Genotype II was identical with strain FUJ-98, genetically close to R. japonica which has been isolated from ticks in China. Genotype V was identical with R. felis and strain California 2 isolated from the cat flea. This is the first report on the detection of R. felis from ticks. Genotype VI detected from Ixodes sp. did not seem to belong to genus Rickettsia. Based on the previous antigenic data and the phylogenetic analysis presented here, Genotype VII should be considered a variant of R. helvetica and genotype VIII detected from I. ovatus and I. persulcatus were identical with R. helvetica. Genotype IX detected from I. nipponensis was genetically close to the strains IRS3, IRS4, and IrR/Munich isolated from I. ricinus in Slovakia and German.  相似文献   

9.
Fascioliasis is a parasitic infection caused by liver flukes. Although several cases have been reported in Korea, phylogenetic analysis of isolates is lacking. In this study, a 66-year-old woman with right upper quadrant (RUQ) abdominal pain was diagnosed as fascioliasis involving abdominal muscle by imaging study. She received praziquantel treatment, but symptoms were not improved. Lateral movement of the abscess lesion was followed. Trematode parasite was surgically removed from the patient’s rectus abdominis muscle. The fluke was identified as Fasciola hepatica based on sequence analysis of 18S rDNA. To determine the phylogenetic position of this Fasciola strain (named Korean Fasciola 1; KF1), the cox1 gene (273 bp) was analyzed and compared with the genes of 17 F. hepatica strains isolated from cows, sheep, goats, and humans from various countries. Phylogenetic analysis showed that KF1 was closely related with the isolates from China goat.  相似文献   

10.
Theories on molecular evolution predict that phylogenetically recent nonsynonymous mutations should contain more non-neutral amino acid replacements than ancient mutations. We analyzed 840 complete coding-region human mitochondrial DNA (mtDNA) sequences for nonsynonymous mutations and evaluated the mutations in terms of the physicochemical properties of the amino acids involved. We identified 465 distinct missense and 6 nonsense mutations. 48% of the amino acid replacements changed polarity, 26% size, 8% charge, 32% aliphaticity, 13% aromaticity, and 44% hydropathy. The reduced-median networks of the amino acid changes revealed relatively few differences between the major continent-specific haplogroups, but a high variation and highly starlike phylogenies within the haplogroups. Some 56% of the mutations were private, and 25% were homoplasic. Nonconservative changes were more common than expected among the private mutations but less common among the homoplasic mutations. The asymptotic maximum of the number of nonsynonymous mutations in European mtDNA was estimated to be 1,081. The results suggested that amino acid replacements in the periphery of phylogenetic networks are more deleterious than those in the central parts, indicating that purifying selection prevents the fixation of some alleles.  相似文献   

11.
利用线粒体CO II基因序列对中国尾蛱蝶属系统分化的研究   总被引:9,自引:0,他引:9  
利用线粒体COII基因序列分析法,研究了我国尾蛱蝶属5种蝴蝶的系统分化。结果表明,在尾蛱蝶属5个种的12个样品中,405 bp长的COII片段有11.4%的位点为多态性位点,大部分的碱基改变是转换。各物种内不同个体间的差异明显小于不同物种间的差异,种内个体间的差异一般为0.5%~1.5%,各物种间的差异绝大多数在4%以上。利用最大似然性法构建的尾蛱蝶属聚类关系图显示,尾蛱蝶属蝴蝶分为两大分支,一支包括大二尾蛱蝶、二尾蛱蝶和忘忧尾蛱蝶,另外一个分支包括窄斑凤尾蛱蝶和黑凤尾蛱蝶聚在一起。在大二尾蛱蝶、二尾蛱蝶和忘忧尾蛱蝶这一分支中,大二尾蛱蝶和忘忧尾蛱蝶的亲缘关系较近,而二尾蛱蝶较远。这些分子系统学的结果均与形态学的结果相一致,是对形态分类的有力支持。  相似文献   

12.
Traditional classification in the genus Capra is based mainly on horn morphology. However, previous investigations based on allozyme data are not consistent with this classification. We thus reexamined the evolutionary history of the genus by analyzing mitochondrial DNA (mtDNA) sequence variation. We collected bone samples from museums or dead animals found in the field. Thirty-four individuals were successfully sequenced for a portion of the mtDNA cytochrome b gene and control region (500 bp in total). We obtained a star-like phylogeny supporting a rapid radiation of the genus. In accordance with traditional classification, mtDNA data support the presence of two clades in the Caucasus and the hypothesis of a domestication event in the Fertile Crescent. However, in conflict with morphology, we found that C. aegagrus and C. ibex are polyphyletic species, and we propose a new scenario for Capra immigration into Europe.  相似文献   

13.
14.
15.
The phylogenetic relationship of the genera Arthroderma and Nannizzia, was investigated by mitochondrial DNA analysis based on the restriction-fragment-length polymorphisms. Phylogenetic trees made on ten species. A. benhamiae, A. insingulare, A. quadrifidum, A. simii, A. vanbreuseghemii, N. fulva, N. grubyia, N. gypsea, N. incurvata and N. otae showed no definite distinctions between the genera Arthroderma and Nannizzia. These results support the conclusion of Weitzman et al. that the genera Arthroderma and Nannizzia are congeneric.  相似文献   

16.
17.
湛江硇洲岛海葵相关可培养细菌系统发育多样性   总被引:6,自引:0,他引:6  
【目的】了解湛江硇洲岛海葵样品中相关可培养细菌的多样性。【方法】运用纯培养法和基于16S rRNA基因序列的系统发育分析对样品中可培养细菌多样性进行研究。【结果】用补充0~2.0 mol/L NaCl 的MA、ISP 2、NA、SWA和HAA培养基从海葵样品中分离到126株细菌,通过形态观察和部分生理生化实验去冗余,选取42株具有代表性的菌株进行基于16S rRNA基因序列的系统发育多样性分析。结果表明,42个分离菌株可分为25个物种,属于3个大的系统发育类群(Firmicutes,Gamma-Proteobacteria,Actinobacteria)、11个科、18个属。多数菌株属于Firmicutes门(17株,40.5%)和Gamma-Proteobacteria亚门(14株,33.3%)。这些分离菌株中,至少有6个菌株可能代表6个不同属的6个新物种:JSM 071004、JSM 071068、JSM 071073、JSM 072002、JSM 073008和JSM073097分别代表Bacillus、Halobacillus、Piscibacillus、Pontibacillus、Alteromonas和Nocardiopsis属的新物种。【结论】从以上结果可以看出,湛江硇洲岛海葵中存在较为丰富的微生物物种多样性和系统发育多样性,并且潜藏着较多的新的微生物类群(物种)。  相似文献   

18.
The molecular phylogeny of the genus Odontobuthus Vachon, 1950 (Scorpiones: Buthidae) in Iran was evaluated using two mitochondrial DNA genes, cytochrome c oxidase, subunit I (COI) and 16S ribosomal RNA (16S rRNA). The molecular phylogenetic analyses were performed using Maximum Parsimony, Maximum Likelihood and Bayesian inference methods. The resulting topologies supported two main clades: the clade comprising Odontobuthus doriae, O. bidentatus, and O. tavighiae, and another one which is the O. tirgari clade. The results clearly presented additional support for the taxonomic validity of the recently described species, O. tirgari and O. tavighiae. In addition, the monophyly of two previously described species O. doriae and O. bidentatus was confirmed. According to the data presented here, three taxonomically valid species belonging to the genus Odontobuthus occur in Iran.  相似文献   

19.
We infer phylogenetic relationships among isopod species of the genus Orthometopon distributed in the Greek area, comparing partial mitochondrial DNA sequences for cytochrome oxidase I (COI). All phylogenetic analyses produced topologically identical trees that revealed a well-resolved phylogeny. These trees support the monophyly of the genus Orthometopon , and suggest two clades that correspond to separate geographical regions (west and east of the mid-Aegean trench). However, the phylogenetic relationships among Greek populations of Orthometopon spp. are different from the presumed pattern on the basis of morphological evidence. The distinct geographical distribution of the major clades of the phylogenetic tree and its topology suggest a spatial and temporal sequence of phylogenetic separations, which coincide with some major palaeogeographical separations during the geological history of the Aegean Sea. The results stress the need for a reconsideration of the evolutionary history of Orthometopon species, which will help overcome difficulties encountered in classical taxonomy at the species level. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 707–715.  相似文献   

20.
The genetic electrophoretic variation at up to 43 protein loci was studied in four hominoid, three cercopithecoid, and three ceboid species. Phylogenetic reconstructions based on genetic distances show that the two chimpanzee species are closest to humans, while the gorilla diverged earlier than the split between humans and the chimpanzee. Within the cercopithecoids the green monkey apparently diverged earlier than the macaques, and within the ceboids, the owl monkey is only distantly related to the capuchin and squirrel monkeys. The hypothesis that rates of evolution at the level of protein electrophoretic variation are equal both among the groups, as well as within each group, could not be rejected.  相似文献   

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