Classification of the family Plectonemertidae (Nemertea): a phenetic comparison

A phenetic classification based on overall morphological similarity between the species in the family Plectonemertidae (genera Plectonemertes, Campbellonemertes, Potamonemertes, Leptonemertes, Katechonemertes, Argonemertes, Anliponemertes, and Acteonemertes) was undertaken and the result compared with a cladistic and an evolutionary classification. Similarity between species was computed by Gower's general coefficient of similarity and various techniques were used to find patterns in the similarity matrix: single-linkage, average-linkage, and complete-linkage clustering, together with principal coordinate analysis. Although the explicit aim of phenetics is not to estimate the phylogeny, the classification based on overall similarity still portrays phylogeny better than an intuitive assessment of morphological similarity, as judged by the cladistic analysis. The classification does not support the previously proposed hypothesis that the two freshwater genera Campbellonemertes and Potamonemertes have descended from a terrestrial ancestor.     

Phylogeny and Cladistic Classification of the Paramonostiliferous Family Plectonemertidae (Phylum Nemertea)

Abstract— Numerical phylogenetic analysis of nemertean species from the genera Plectonemertes, Katechonemertes and Acteonementes (marine), Argonemertes, Antiponemertes and Leptonemertes (terrestrial), Potamonemertes and Campbellonemertes (freshwater) in the family Plectonemertidae was carried out with the following aims. (1) To estimate the evolutionary relationships between and among these species. (2) To lest the hypothesis of Moore and Gibson that the analysed freshwater species originated from a terrestrial ancestor. (3) To classify the species in monophyletic genera. The analysis did not confirm the hypothesis that the freshwater habitat has been colonised via land. Instead, it suggests that both terrestrial and freshwater species within this family have evolved from a marine ancestor. The cladogram suggests that Antiponemetes is paraphyletic, and it is combined with Argonemertes to form a monophyletic genus.     

Genome relationship among nine species of Millettieae (Leguminosae: Papilionoideae) based on random amplified polymorphic DNA (RAPD)

Random amplified polymorphic DNA (RAPD) marker was used to establish intergeneric classification and phylogeny of the tribe Millettieae sensu Geesink (1984) (Leguminosae: Papilionoideae) and to assess genetic relationship between 9 constituent species belonging to 5 traditionally recognized genera under the tribe. DNA from pooled leaf samples was isolated and RAPD analysis performed using 25 decamer primers. The genetic similarities were derived from the dendrogram constructed by the pooled RAPD data using a similarity index, which supported clear grouping of species under their respective genera, inter- and intra-generic classification and phylogeny and also merger of Pongamia with Millettia. Elevation of Tephrosia purpurea var. pumila to the rank of a species (T. pumila) based on morphological characteristics is also supported through this study of molecular markers.     

Relationships within the family Actiniidae (Cnidaria,Actiniaria) based on molecular characters

Current sea anemone systematics is based on relatively few morphological characters, and potentially could benefit from the use of molecular characters. In this paper, the phylogenetic relationships of 12 species from 6 genera in the family Actiniidae have been investigated using electrophoretically separated isozymes. A numerical cladistic analysis has produced an estimated phylogeny. The implications of this phylogeny for the taxonomic use of certain morphological characters are discussed.     

Preliminary comments on a phylogenetic study of the order Diphyllidea van Beneden in Carus, 1863

The basis for a preliminary analysis of the relationships within the monophyletic Diphyllidea is outlined. Information on morphological characters and their interpretation within a phylogenetic context are presented. A cladistic analysis at the species level was conducted based on a matrix of 21 morphological characters. Character polarity was determined by taxonomic outgroup analysis relative to the basal orders, Pseudophyllidea and Haplobothriidea. The phylogeny for the diphyllideans was found to be poorly resolved based on characters currently available for evaluation. Computer assisted cladistic analysis found three equally parsimonious trees with a consistency index of 0.54. The topology of these trees shows that Ditrachybothridium macrocephalum is the basal taxon and the putative sister group for species of Echinobothrium; Macrobothridium rhynchobati is grouped among species of Echinobothrium. If the classification is to be consistent with this tree, M. rhynchobati should be included in the genus Echinobothrium. This observation should be carefully examined, considering the relative paucity of useful morphological characters currently available for this group.     

Phylogenetic analyses of marine sponges within the order Verongida: a comparison of morphological and molecular data

Abstract. Because the taxonomy of marine sponges is based primarily on morphological characters that can display a high degree of phenotypic plasticity, current classifications may not always reflect evolutionary relationships. To assess phylogenetic relationships among sponges in the order Verongida, we examined 11 verongid species, representing six genera and four families. We compared the utility of morphological and molecular data in verongid sponge systematics by comparing a phylogeny constructed from a morphological character matrix with a phylogeny based on nuclear ribosomal DNA sequences. The morphological phylogeny was not well resolved below the ordinal level, likely hindered by the paucity of characters available for analysis, and the potential plasticity of these characters. The molecular phylogeny was well resolved and robust from the ordinal to the species level. We also examined the morphology of spongin fibers to assess their reliability in verongid sponge taxonomy. Fiber diameter and pith content were highly variable within and among species. Despite this variability, spongin fiber comparisons were useful at lower taxonomic levels (i.e., among congeneric species); however, these characters are potentially homoplasic at higher taxonomic levels (i.e., between families). Our molecular data provide good support for the current classification of verongid sponges, but suggest a re-examination and potential reclassification of the genera Aiolochroia and Pseudoceratina . The placements of these genera highlight two current issues in morphology-based sponge taxonomy: intermediate character states and undetermined character polarity.     

A phylogenetic analysis of subtribe Pleurothallidinae (Orchidaceae)

A cladistic analysis of subtribe, Pleurothallidinae (Orchidaceae) is based on 45 anatomical/ morphological characters. The ingroup members comprise 24 genera; the large genus Pleurothallis consists of two subgenera and ten species complexes. Three taxa representing subtribes Laeliinae and Arpophyllinae are designated as outgroup. Eight most parsimonious trees were discovered using computer assisted software (length = 230; CI = 0.27). The hypothesis that subtribe Pleurothallidinae has undergone a unilinear reduction in the number of pollinia is not supported by this study. Although the eight-pollinia state as represented by Octomeria apparently is plesiomorphic, the two-pollinia and four-pollinia states arose early in the phylogeny of the subtribe. Both two-and four-pollinia states subsequently reappeared as parallelisms. The six-pollinia state exhibited in Brachionidium is autapomorphic. This cladistic analysis suggests that Pleurothallis is not a natural genus and, perhaps may be divided into several discrete genera.     

螟黄足盘绒茧蜂复合群支序系统学研究（膜翅目：茧蜂科：小腹茧蜂亚科）

对螟黄足盘绒茧蜂复合群Cotesia flavipes complex (膜翅目：茧蜂科：小腹茧蜂亚科)分布全世界的5个种和外群侧沟茧蜂Microplitis 及荻茧蜂Diolcogaster 的25个性状,以及复合群5个种和外群螟蛉盘绒茧蜂Cotesia ruficrus、粘虫盘绒茧蜂Cotesia kariyai、粉蝶盘绒茧蜂Cotesia glomerata 的24个性状,分别进行比较研究,并运用支序分析的方法探讨该复合群内5个种种间的系统发育关系。支序分析表明螟黄足盘绒茧蜂复合群是一单系群,二化螟盘绒茧蜂C. chilonis 和大螟盘绒茧蜂C. sesamiae 近缘,芦螟盘绒茧蜂C. chiloluteelli 和汉寿盘绒茧蜂C. hanshouensis 近缘,螟黄足盘绒茧蜂C. flavipes相对独立。 以上研究表明无论是以近缘属作外群还是以同属其它种作外群,所得结果基本上都能反映螟黄足盘绒茧蜂复合群各种之间的分类地位。     

国剑角蝗科部分属种雌性下生殖板的形态及演化（直翅目：蝗总科）

从20世纪60年代至今的一些研究已基本肯定了蝗虫雌性下生殖板的分类价值。本文选择了中国剑角蝗科6属10种蝗虫对其雌性下生殖板进行了形态学和演化分析。结果表明雌性下生殖板的形态在研究的6属内都是稳定的,属间差异明显。这6个属的系统发育关系为：（卡蝗属（（佛蝗属,戛蝗属）,（菊蝗属（蝗属,剑角蝗属））））,这一结果和形态分类是一致的,支持长腹蝗亚科从剑角蝗科分开。文中还分析了剑角蝗科雌性下生殖板各性状的演化方向。     

虎尾草亚科系统发育关系的初步研究

运用广义形态学性状对虎尾草亚科（Chloridoideae）进行系统发育分析。内类群包括虎尾草亚科52属的69种植物,代表虎尾草亚科的主要类群;芦竹亚科（Arundinoideae）扁芒草族（Danthonieae）的Centropodia和Danthonia被选作外类群。分支分析表明,虎尾草亚科是一个单系类群。其严格一致树包括A、B、C、D、E5个分支。两个大族画眉草族（Eragrostideae）和虎尾草族（Chlorideae）代表虎尾草亚科内部类群分化的两个方向,分开处理较合理。细穗草族（Leptureae）放到虎尾草族中较合理。冠芒草族（Pappophoreae）是虎尾草亚科的基部类群,与画眉草族近缘。我们的研究支持虎尾草亚科从旧世界向新世界扩散的地理分布假说,并提供了虎尾草亚科属上类群的系统发育关系的框架。     

Phylogeny of Trichomonads Based On Partial Sequences of Large Subunit Rrna and On Cladistic Analysis of Morphological Data

ABSTRACT. Several domains of large subunit rRNA from nine trichomonad species have been sequenced. Molecular phylogenies obtained with parsimony and distance methods demonstrate the trichomonads are a monophyletic group which branches very early in the eukaryotic tree. the topology of the trees is in general agreement with traditional views on evolutionary and systematic relationships of trichomonads. A clear dichotomy is noted between the subfamily Trichomonadinae and the subfamily Tritrichomonadinae. In the latter subfamily, a second division separates the " Tritrichomonas muris -type" species from the " Tritrichomonas augusta -type" ones. Previous evolutionary schemes in which the Monocercomonadidae were regarded as the most "primitive" and the Trichomonadidae as more "evolved" are not in agreement with our molecular data. the emergence of Monocercomonas and Hypotrichomonas at the base of the Tritrichomonas lineage suggests a secondary loss of some cytoskeletal structures, the costa and undulating membrane in these genera. This is corroborated by the early branching position of Trichomitus. which possesses a costa and an undulating membrane and has usually been placed among the Trichomonadidae on the basis of cytological characters. A cladistic analysis was applied to the available morphological characters in order to produce a hierarchical grouping of the taxa reflecting their morphological diversity. Supplementary key words. Evolution, molecular phylogeny, morphological cladistic analysis.     

Phylogeny, host-parasite relationship and zoogeography

Phylogeny is the evolutionary history of a group or the lineage of organisms and is reconstructed based on morphological, molecular and other characteristics. The genealogical relationship of a group of taxa is often expressed as a phylogenetic tree. The difficulty in categorizing the phylogeny is mainly due to the existence of frequent homoplasies that deceive observers. At the present time, cladistic analysis is believed to be one of the most effective methods of reconstructing a phylogenetic tree. Excellent computer program software for phylogenetic analysis is available. As an example, cladistic analysis was applied for nematode genera of the family Acuariidae, and the phylogenetic tree formed was compared with the system used currently. Nematodes in the genera Nippostrongylus and Heligmonoides were also analyzed, and the validity of the reconstructed phylogenetic trees was observed from a zoogeographical point of view. Some of the theories of parasite evolution were briefly reviewed as well. Coevolution of parasites and humans was discussed with special reference to the evolutionary relationship between Enterobius and primates.     

Higher level phylogeny for the passion-vine butterflies (Nymphalidae, Heliconiinae) based on early stage and adult morphology

A higher level phylogeny for the passion-vine butterflies (Nymphalidae, Heliconiinae) was generated by cladistic analysis of 146 morphological characters from all life stages. The 24 species studied were selected representatives of the ten currently accepted genera of the sub-tribe Heliconiiti. Analyses of only characters from larvae and pupae did not produce well resolved trees. However, some characters of the immature stages provided critical support for the monophyly of two clades. Analysis of only adult characters yielded a tree that closely resembled that obtained from all data combined. The phylogeny here derived from the combined analysis of early stage and adult characters differed in topology from all previously proposed hypotheses, and supported the monophyly of all currently recognized genera. Characters supporting each clade are described and illustrated, and various hypotheses of phylogenetic relatedness of passion-vine butterfly taxa are discussed.     

中国瘤锥蝗科和锥头蝗科的支序系统学研究

通过比较中国分布的瘤锥蝗科Chrotogonidae和锥头蝗科Pyrgomorphidae10属蝗虫的形态学性状,选择了22个性状对10属蝗虫的系统发育关系进行支序系统学分析。结果表明：从支序图来看这10个属的关系相互交织在一起,不能区别为两个科。笔者建议在蝗虫分类系统中,把锥头蝗科和瘤锥蝗科合在一起作为一个科比较妥当。     

Phylogenetic analysis of the Monocotylidae (Monogenea) inferred from 28S rDNA sequences

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.     

How the worm got its pharynx: phylogeny, classification and Bayesian assessment of character evolution in Acoela

Acoela are marine microscopic worms currently thought to be the sister taxon of all other bilaterians. Acoels have long been used as models in evolutionary scenarios, and generalized conclusions about acoel and bilaterian ancestral features are frequently drawn from studies of single acoel species. There is no extensive phylogenetic study of Acoela and the taxonomy of the 380 species is chaotic. Here we use two nuclear ribosomal genes and one mitochondrial gene in combination with 37 morphological characters in an analysis of 126 acoel terminals (about one-third of the described species) to estimate the phylogeny and character evolution of Acoela. We present an estimate of posterior probabilities for ancestral character states at 31 control nodes in the phylogeny. The overall reconstruction signal based on the shape of the posterior distribution of character states was computed for all morphological characters and control nodes to assess how well these were reconstructed. The body-wall musculature appears more clearly reconstructed than the reproductive organs. Posterior similarity to the root was calculated by averaging the divergence between the posterior distributions at the nodes and the root over all morphological characters. Diopisthoporidae is the sister group to all other acoels and has the highest posterior similarity to the root. Convolutidae, including several "model" acoels, is most divergent. Finally, we present a phylogenetic classification of Acoela down to the family level where six previous family level taxa are synonymized.     

Three-dimensional analysis of mandibular dental root morphology in hominoids

Although often preserved in the fossil record, mandibular dental roots are rarely used for evolutionary studies. This study qualitatively and quantitatively characterizes the three-dimensional morphology of hominoid dental roots. The sample comprises extant apes as well as two fossil species, Khoratpithecus piriyai and Ouranopithecus macedoniensis. The morphological differences between extant genera are observed, quantified and tested for their potential in systematics. Dental roots are imaged using X-ray computerized tomography, conventional microtomography and synchrotron microtomography. Resulting data attest to the high association between taxonomy and tooth root morphology, both qualitatively and quantitatively. A cladistic analysis based on the dental root characters resulted in a tree topology congruent with the consensus phylogeny of hominoids, suggesting that tooth roots might provide useful information in reconstructing hominoid phylogeny. Finally, the evolution of the dental root morphology in apes is discussed.     

Phylogeny of Geomydoecus and Thomomydoecus pocket gopher lice (Phthiraptera: Trichodectidae) inferred from cladistic analysis of adult and first instar morphology

The phylogeny for all 122 species and subspecies of chewing lice of the genera Geomydoecus and Thomomydoecus (Phthiraptera: Trichodectidae) hosted by pocket gophers (Rodentia: Geomyidae) is estimated by a cladistic analysis of fifty-eight morphological characters obtained from adults and first instars. The data set has considerable homoplasy, but still contains phylogenetic information. The phylogeny obtained is moderately resolved and, with some notable exceptions, supports the species complexes proposed by Hellenthal and Price over the the last two decades. The subgenera G. (Thaelerius) and T. (Thomomydoecus) are both shown to be monophyletic, but the monophly of subgenus T. (Jamespattonius) could not be confirmed, perhaps due to the lack of first-instar data for one of its component species. The nominate subgenus of Geomydoecus may be monophyletic, but our cladogram was insufficiently resolved to corroborate this. Mapping the pocket gopher hosts onto the phylogeny reveals a consistent pattern of louse clades being restricted to particular genera or subgenera of gophers, but the history of the host-parasite association appears complex and will require considerable effort to resolve.