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Molecular Characters (molecular + character)
Selected AbstractsSimultaneous analysis of basal Hymenoptera (Insecta): introducing robust-choice sensitivity analysisBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2003SUSANNE SCHULMEISTER Molecular characters are analysed on their own and in combination with morphological data to examine the phylogenetic relationships of the basal lineages of Hymenoptera (,Symphyta'). This study covers 47 sawfly genera and nine apocritan families and includes molecular sequences from five genes , 12S, 16S, 18S and 28S ribosomal genes and cytochrome oxidase 1 , as well as 343 morphological characters. A robust-choice sensitivity analysis is performed with the data. First, the simultaneous analysis is repeated three times, each time employing a different step matrix for weighting the transformations of the molecular characters. Then, the results of all three simultaneous analyses are summarized in a strict consensus in order to avoid basing the conclusions on a narrow set of assumptions. This methodology is discussed in the paper. The relationships among superfamilies largely confirm previous hypotheses, being (Xyeloidea (Tenthredinoidea s.l. (Pamphilioidea (Cephoidea (Siricoidea (Xiphydrioidea (Orussoidea Apocrita))))))), where Siricoidea is understood as Siricidae+Anaxyelidae. However, the relationships within Tenthredinoidea s.s. proposed here are novel: ({Argidae Pergidae}[Athalia{(Diprionidae Cimbicidae) Tenthredinidae minus Athalia}]). © 2003 The Linnean Society of London. Biological Journal of the Linnean Society, 2003, 79, 245,275. [source] Effect of PCBM Concentration on Photoluminescence Properties of Composite MEH-PPV/PCBM Nanoparticles Investigated by a Franck,Condon Analysis of Single-Particle Emission SpectraCHEMPHYSCHEM, Issue 14 2009Daeri Tenery Dr. Abstract The emission of composite conjugated polymer (MEH-PPV)/fullerene (PCBM) nanoparticles is investigated by single particle spectroscopy (SPS), and changes in vibronic structure with nanoparticle composition are evaluated by means of a detailed Franck,Condon analysis. Consistent with previous reports we find that the emission spectra can be modeled as the superposition of two types of emitters, one with aggregate character and one with molecular character. Major findings from the fitting of the SPS data to a Franck,Condon model are that 1) the occurrence of each of the two types of emitters changes with nanoparticle composition to the point that no aggregate emitters are detected (at 50 wt,% PCBM), 2) at the highest PCBM doping levels (75 wt,% PCBM) aggregate emitters reappear due to nanoscale phase separation in the composite nanoparticles, 3) the molecular emitters show small Huang,Rhys factors that increase with PCBM doping, indicative of extensive delocalization and exciton migration that is reduced by the disorder introduced in the polymer material by PCBM doping and 4) the aggregate emitters show large Huang,Rhys factors, indicative of the localized nature of these energy trap sites, with a broad distribution of values of these Huang,Rhys factors. The latter observation suggests a broad heterogeneous distribution of aggregate morphologies in blended conducting polymer materials, which can be attributed to variations in polymer chain folding and stacking at the aggregate sites. The reported results obtained by the SPS approach show how blending conjugated polymers with fullerenes at various doping levels induces changes in interchain interactions and aggregate site density even at length scales below a few tens of nanometers that affect conjugated polymer material properties, an observation that has gone unnoticed in bulk studies of blended conjugated polymer films. [source] Ultrastructure of sperms in Acoela (Acoelomorpha) and its concordance with molecular systematicsINVERTEBRATE BIOLOGY, Issue 3 2004Anatoly Petrov Abstract. The sperms of the Acoela, a group of lower worms, are filiform cells with 2 flagella incorporated into the cell body. Their axonemes can variously have 9+2, 9+1, or 9+0 patterns of microtubules; and singlet microtubules in the cell body can be arranged in axial or cortical positions. An analysis of phylogenetic relationships of acoels based on molecular characters (18S rDNA sequence data) showed that these patterns of microtubules, where known, fell into discrete monophyletic groups. To test this hypothesis, we have expanded the database of sperm characters by examining the ultrastructure of a further 10 species representing 4 acoel families. As expected, the Convolutidae fell into 2 unrelated groups: "small-bodied convolutids"(Convoluta pulchra, Praeconvoluta tigrina, Pseudaphanostoma smithrii) having 9+2 axonemes and cortical microtubules, and "large-bodied convolutids" (including Wulguru cuspidata) having 9+0 axonemes and axial microtubules. Also, as expected, a member of the Mecynostomidae (Paedomecynostomum bruneum) has 9+1 axonemes and axial microtubules. Members of a family that appears intermediate by molecular characters, the Otocelididae, significantly have a variety of patterns: axonemes with both 9+2 and 9+0 patterns (Notocelis gullmarensis) or just 9+2 (the other species), and either axial (Philocelis brueggemanni), both axial and cortical (N. gullmarensis) microtubules, or microtubules that bend between axial and cortical positions along the length of the sperm (Otocelis sandara). Members of the Dakuidae (Daku woorimensis) also belong to this intermediate group, having 9+2 axonemes and axial microtubules, while in a fifth otocelidid (Stomatricha hochbergi), sperm characters are like those of the "large-bodied convolutids" (9+0 axonemes and axial microtubules). Characters of sperm morphology generally support the molecular hypothesis of relationships and confirm a suspected polyphyly of the families Convolutidae, Otocelididae, and Actinoposthiidae. [source] Cladistic analysis of Medusozoa and cnidarian evolutionINVERTEBRATE BIOLOGY, Issue 1 2004Antonio C. Marques Abstract. A cladistic analysis of 87 morphological and life history characters of medusozoan cnidarians, rooted with Anthozoa, results in the phylogenetic hypothesis (Anthozoa (Hydrozoa (Scyphozoa (Staurozoa, Cubozoa)))). Staurozoa is a new class of Cnidaria consisting of Stauromedusae and the fossil group Conulatae. Scyphozoa is redefined as including those medusozoans characterized by strobilation and ephyrae (Coronatae, Semaeostomeae, and Rhizostomeae). Within Hydrozoa, Limnomedusae is identified as either the earliest diverging hydrozoan lineage or as the basal group of either Trachylina (Actinulida (Trachymedusae (Narcomedusae, Laingiomedusae))) or Hydroidolina (Leptothecata (Siphonophorae, Anthoathecata)). Cladistic results are highly congruent with recently published phylogenetic analyses based on 18S molecular characters. We propose a phylogenetic classification of Medusozoa that is consistent with phylogenetic hypotheses based on our cladistic results, as well as those derived from 18S analyses. Optimization of the characters presented in this analysis are used to discuss evolutionary scenarios. The ancestral cnidarian probably had a sessile biradial polyp as an adult form. The medusa is inferred to be a synapomorphy of Medusozoa. However, the ancestral process (metamorphosis of the apical region of the polyp or lateral budding involving an entocodon) could not be inferred unequivocally. Similarly, character states for sense organs and nervous systems could not be inferred for the ancestral medusoid of Medusozoa. [source] Molecular systematics of Scaphirhynchinae: an assessment of North American and Central Asian Freshwater Sturgeon SpeciesJOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2007C. B. Dillman Summary The sturgeon subfamily Scaphirhynchinae contains two genera of obligate freshwater sturgeon: Scaphirhynchus and Pseudoscaphirhynchus, from North America and Central Asia, respectively. Both genera contain morphologically variable species. A novel data set containing multiple individuals representing four diagnosable morphological variants for two species of Pseudoscaphirhynchus, P. hermanni and P. kaufmanni, was generated. These data were used to test taxonomic hypotheses of monophyly for the subfamily Scaphirhynchinae, monophyly of both Scaphirhynchus and Pseudoscaphirhynchus, monophyly of P. hermanni and P. kaufmanni, and monophyly of the recognized morphological variants. Monophyly of the subfamily Scaphirhynchinae is consistently rejected by all phylogenetic reconstruction methodologies with the molecular character set while monophyly of both river sturgeon genera is robustly supported. The molecular data set also rejects hypotheses of monophyly for sampled species of Pseudoscaphirhynchus as well as monophyly for the recognized intraspecific morphological variants. Interestingly both Scaphirhynchus and Pseudoscaphirhynchus demonstrate the same general pattern in reconstructed topologies; a lack of phylogenetic structure in the clade with respect to recognized diversity. Despite rejection of monophyly for the subfamily Scaphirhynchinae with molecular data, reconstructed hypotheses from morphological character sets consistently support monophyly for this subfamily. Disparities among the data sets, as well as reasons for rejection of monophyly for Scaphirhynchinae and species of Scaphirhynchus and Pseudoscaphirhynchus with molecular characters are examined and a decreased rate of molecular evolution is found to be most consistent with the data. [source] The effect of environmental diversification on species diversification in New Caledonian caddisflies (Insecta: Trichoptera: Hydropsychidae)JOURNAL OF BIOGEOGRAPHY, Issue 5 2010Marianne Espeland Abstract Aim, To test whether environmental diversification played a role in the diversification of the New Caledonian Hydropsychinae caddisflies. Location, New Caledonia, south-west Pacific. Methods, The phylogeny of the New Caledonian Hydropsychinae caddisflies was hypothesized using parsimony and Bayesian methods on molecular characters. The Bayesian analysis was the basis for a comparative analysis of the correlation between phylogeny and three environmental factors: geological substrate (ultrabasic, non-ultrabasic), elevation and precipitation. Phylogenetic divergence times were estimated using a relaxed clock method, and environmental factors were mapped onto a lineage-through-time plot to investigate the timing of environmental diversification in relation to species radiation. The correlation between rainfall and elevation was tested using independent contrasts, and the gamma statistic was calculated to infer the diversification pattern of the group. Results, The diversification of extant Orthopsyche,Caledopsyche species began in the Middle,Late Oligocene, when much of the island of New Caledonia was covered by ultrabasic substrate and mountain forming was prevalent. Most lineages originated in the Middle,Late Miocene, a period associated with long-term climate oscillation. Optimization of environmental factors on the phylogeny demonstrated that the New Caledonian Hydropsychinae group adapted to ultrabasic substrate early in its evolutionary history. The clade living mostly on ultrabasic substrate was far more species-rich than the clade living mostly on non-ultrabasic substrate. Elevation and rainfall were significantly correlated with each other. The lineage-through-time plot revealed that the main environmental diversification preceded species diversification. A constant speciation through time was rejected, and the negative gamma indicates that most of the diversification occurred early in the history of the clade. According to the inferred phylogeny, the genus Orthopsyche McFarlane is a synonym under Caledopsyche Kimmins, and Abacaria caledona Oláh & Barnard should also be included in Caledopsyche. Main conclusions, The age of the radiation does not support a vicariance origin of New Caledonian Hydropsychinae caddisflies. Environmental diversification pre-dates lineage diversification, and thus environmental heterogeneity potentially played a role in the diversification of the group, by providing a variety of fragmented habitats to disperse into, promoting speciation. The negative gamma indicates that the speciation rate slowed as niches started to fill. [source] Differentiation of morphology, genetics and electric signals in a region of sympatry between sister species of African electric fish (Mormyridae)JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 4 2008S. LAVOUÉ Abstract Mormyrid fishes produce and sense weak electric organ discharges (EODs) for object detection and communication, and they have been increasingly recognized as useful model organisms for studying signal evolution and speciation. EOD waveform variation can provide important clues to sympatric species boundaries between otherwise similar or morphologically cryptic forms. Endemic to the watersheds of Gabon (Central Africa), Ivindomyrus marchei and Ivindomyrus opdenboschi are morphologically similar to one another. Using morphometric, electrophysiological and molecular characters [cytochrome b sequences and amplified fragment length polymorphism (AFLP) genotypes], we investigated to what extent these nominal mormyrid species have diverged into biological species. Our sampling covered the known distribution of each species with a focus on the Ivindo River, where the two taxa co-occur. An overall pattern of congruence among datasets suggests that I. opdenboschi and I. marchei are mostly distinct. Electric signal analysis showed that EODs of I. opdenboschi tend to have a smaller initial head-positive peak than those of I. marchei, and they often possess a small third waveform peak that is typically absent in EODs of I. marchei. Analysis of sympatric I. opdenboschi and I. marchei populations revealed slight, but significant, genetic partitioning between populations based on AFLP data (FST , 0.04). Taken separately, however, none of the characters we evaluated allowed us to discriminate two completely distinct or monophyletic groups. Lack of robust separation on the basis of any single character set may be a consequence of incomplete lineage sorting due to recent ancestry and/or introgressive hybridization. Incongruence between genetic datasets in one individual, which exhibited a mitochondrial haplotype characteristic of I. marchei but nevertheless fell within a genetic cluster of I. opdenboschi based on AFLP genotypes, suggests that a low level of recent hybridization may also be contributing to patterns of character variation in sympatry. Nevertheless, despite less than perfect separability based on any one dataset and inconclusive evidence for complete reproductive isolation between them in the Ivindo River, we find sufficient evidence to support the existence of two distinctive species, I. opdenboschi and I. marchei, even if not ,biological species' in the Mayrian sense. [source] ARE CYTOPLASMIC POCKETS (MTR/POCKET) PRESENT IN ALL PHOTOSYNTHETIC EUGLENOID GENERA?1JOURNAL OF PHYCOLOGY, Issue 4 2002Woongghi Shin In 1985, the existence of a cytoplasmic pocket formed from the reservoir membrane in the photosynthetic euglenoid Colacium was described. A band of reinforcing microtubules (MTR) derived from the ventral flagellar root lined the pocket, and a dense fibrillar mesh was associated with the membrane. A comparison of bodonid cytostomes, colorless euglenoid cytostomes, and the reservoir pocket found in Colacium suggested that the three structures were homologous and that photosynthetic euglenoids arose from phagotrophic ancestors. MTR/pockets have since been reported in other photosynthetic euglenoids, including Euglena, Eutreptia, Eutreptiella, Cryptoglena, Tetreutreptia, and Phacus. We found MTR/pockets in three additional taxa, Lepocinclis, Trachelomonas, and Strombomonas, thereby demonstrating the presence of this complex in representatives of all the major photosynthetic genera. A comparison of the MTR/pocket complex across genera indicated a reduction in structural complexity that was consistent with recent phylogenetic schemes based on molecular characters. Three alternative hypotheses of the origin of MTR/pockets in phototrophic euglenoids are presented and discussed. [source] Ecdysozoa versus Articulata: clades, artifacts, prejudicesJOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 3 2001ZRZAVÝ The claim that monophyly of the Ecdysozoa is caused by chance similarities in 18S rDNA sequences (Wägele et al., J. Zool. Syst. Evol. Res. 37, 211,223, 1999) is re-analysed from the cladistic point of view. It is shown that the molecular characters supporting the Ecdysozoa do not behave as ,noisy' in empirical studies that use the sensitivity analysis and character congruence approaches. The ,anti-noise' methodology proposed by Wägele et al. (1999) is unable to identify true misinformative data. The monophyly of the Articulata (= Annelida + Panarthropoda), proposed by Wägele et al. (1999), is contradicted by all molecular data that support either Ecdysozoa (including Panarthropoda), or Lophotrochozoa (including Annelida), or usually both. Articulata versus Ecdysozoa: Monophyla, Artefakte, Vorurteile Die Behauptung, dass die Monophylie der Ecdysozoa auf einer zufälligen Ähnlichkeit der 18S rDNA Sequenzen basiert (Wägele et al., J. Zool. Syst. Evol. Res. 37, 211,223, 1999) wurde mit kladistischen Methoden neu analysiert. Es wird gezeigt, daß die molekularen Kriterien, welche die Ecdysozoa auszeichnen, sich in empirischen Studien nicht als ,noisy' verhalten, wenn Sensitivitäts-Analysen und Charakter-Kongruenz-Methoden angewandt werden. Au,erdem erweist sich die ,Anti-noise'-Methode, welche von Wägele et al. (1999) vorgeschlagen wurde, als unfähig, wahre mißinformative Daten zu identifizieren. Der Monophylie der Articulata (= Annelida + Panarthropoda), wie sie von Wägele et al. (1999) vorgeschlagen wird, widerspricht allen molekularen Kriterien, welche entweder die Ecdysozoa (inkl. Panarthropoda), Lophotrochozoa (inkl. Annelida) oder sogar beide unterstützen. [source] Phylogeny and phylogeography of squirrel monkeys (genus Saimiri) based on cytochrome b genetic analysisAMERICAN JOURNAL OF PRIMATOLOGY, Issue 3 2010Anne Lavergne Abstract Squirrel monkeys (genus Saimiri) are distributed over a wide area encompassing the Amazon Basin: French Guiana, Suriname, and Guyana, together with Western Panama and Western Costa Rica. The genus Saimiri includes a complex of species and subspecies displaying considerable morphological variation. Taxonomic and systematic studies have identified, in this genus, one to seven species comprising up to 16 subspecies. The phylogenetic relationships between these taxa are poorly understood. Molecular markers have yielded a consistent framework for the systematics of Central and South American Saimiri, identifying four distinct clades: S. oerstedii, S. sciureus, S. boliviensis, and S. ustus. Here, we reconsider the phylogenetic and biogeographic history of Saimiri on the basis of mitochondrial (mtDNA) sequence data, focusing mostly on individuals originating from the Amazon Basin. We studied 32 monkeys with well-defined geographic origins and inferred the phylogenetic relationships between them on the basis of full-length cytochrome b gene nucleotide sequences. The high level of gene diversity observed (0.966) is consistent with the high level of behavioral and morphological variation observed across the geographic range of the genus: 20 mtDNA haplotypes were identified with a maximum divergence of 4.81% between S. b. boliviensis and S. ustus. In addition to confirming the existence of the four clades previously identified on the basis of molecular characters, we suggest several new lineages, including S. s. macrodon, S. s. albigena, S. s. cassiquiarensis, and S. s. collinsi. We also propose new patterns of dispersion and diversification for the genus Saimiri, and discuss the contribution of certain rivers and forest refuges to its structuring. Am. J. Primatol. 72:242,253, 2010. © 2009 Wiley-Liss, Inc. [source] Sheep genetic diversity in Bhutan using microsatellite markersANIMAL SCIENCE JOURNAL, Issue 2 2010Tashi DORJI ABSTRACT Genotype data from eight microsatellite markers were used to assess genetic diversity and relationships among five indigenous Bhutanese sheep populations, Sakten, Jakar, Sarpang, Sipsu and Tsirang. Estimates of mean observed and expected heterozygosities, mean number of alleles per locus/population were obtained. The highest observed heterozygosities were found in Jakar (0.657) and Sakten (0.647), while the lowest one was found in Tsirang (0.539). Genetic distances, pairwise proportion of different alleles, UPGMA tree, and principal component analysis indicate close relationship among Tsirang, Sipsu and Sarpang populations, while Jakar and Sakten populations are located in one cluster. These two clusters are separated geographically, and show distinct phenotypic as well as molecular characters. We therefore recommend that the Bhutanese native sheep populations be classified into at least two distinct breeds, Jakar-Sakten sheep and Sipsu sheep. Since Jakar and Sakten sheep have different morphological phenotypes, further analyses will be required to understand the genetic differences between these two sheep populations. [source] Biogeography and diversity among montane populations of mouse shrew (Soricidae: Myosorex) in TanzaniaBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2010WILLIAM T. STANLEY We assess variation in morphological and molecular characters among three species of Myosorex (the mouse shrew) ,Myosorex geata, Myosorex kihaulei, and Myosorex zinki, as a means to test previously proposed biogeographic hypotheses for Tanzanian ,sky islands' and systematic hypotheses for Tanzanian mouse shrews. We analyse 17 cranial and dental variables using multivariate statistics and perform phylogenetic and phylogeographic analyses on sequences of mitochondrial and nuclear DNA; samples are drawn from every known Tanzanian population of Myosorex. Morphometric and phylogenetic analyses reveal that M. zinki is distinct, but that currently isolated populations of M. geata and M. kihaulei are relatively similar to one another, and may not have been isolated over geological time scales. Analyses of molecular variance identify statistically significant, but limited, genetic variation within and between isolated populations of M. geata and M. kihaulei. Between two putative regional biogeographic boundaries, greater genetic variation is explained by grouping populations on either side of the Ruaha River than by grouping populations on either side of the Makambako Gap. Our results are in agreement with recent studies illustrating the close relationship between faunas of the Southern Highlands and southern Eastern Arc Mountains, diminishing the apparent importance of the Makambako Gap as a historical biogeographic barrier. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 669,680. [source] ,After Africa': the evolutionary history and systematics of the genus Charaxes Ochsenheimer (Lepidoptera: Nymphalidae) in the Indo-Pacific regionBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2010CHRIS J. MÜLLER The predominantly Afrotropical genus Charaxes is represented by 31 known species outside of Africa (excluding subgenus Polyura Billberg). We explored the biogeographic history of the genus using every known non-African species, with several African species as outgroup taxa. A phylogenetic hypothesis is proposed, based on molecular characters of the mitochondrial genes cytochrome oxidase subunit I (COI) and NADH dehydrogenase 5 (ND5), and the nuclear wingless gene. Phylogenetic analyses based on maximum parsimony and Bayesian inference of the combined dataset implies that the Indo-Pacific Charaxes form a monophyletic assemblage, with the exception of Charaxes solon Fabricius. Eight major lineages are recognized in the Indo-Pacific, here designated the solon (+African), elwesi, harmodius, amycus, mars, eurialus, latona, nitebis, and bernardus clades. Species group relationships are concordant with morphology and, based on the phylogeny, we present the first systematic appraisal and classification of all non-African species. A biogeographical analysis reveals that, after the genus originated in Africa, the evolutionary history of Charaxes in the Indo-Pacific, in particular Wallacea, may be correlated with the inferred geological and climatic history of the region. We propose that Wallacea was the area of origin of all Charaxes (excluding C. solon) occurring to the east of Wallace's [1863] Line. The earliest Indo-Pacific lineages appear to have diverged subsequent to the initial fragmentation of a palaeo-continent approximately 13 million years ago. Further diversification in Indo-Pacific Charaxes appears primarily related to climatic changes during the Pliocene and possibly as recently as the Pleistocene. Although both dispersal and vicariance have played important roles in the evolution of the genus within the region, the latter has been particularly responsible for diversification of Charaxes in Wallacea. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 457,481. [source] Tracking island colonization history and phenotypic shifts in Indian Ocean bulbuls (Hypsipetes: Pycnonotidae)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2005BEN H. WARREN Molecular phylogenies of island organisms provide useful systems for testing hypotheses of convergent or parallel evolution, since selectively neutral molecular characters are likely to be independent of phenotype, and the existence of similar environments on multiple isolated islands provides numerous opportunities for populations to evolve independently under the same constraints. Here we construct a phylogenetic hypothesis for Hypsipetes bulbuls of the western Indian Ocean, and use this to test hypotheses of colonization pattern and phenotypic change among islands of the region. Mitochondrial sequence data were collected from all extant taxa of the region, combined with sequence data from relevant lineages in Asia. Data are consistent with a single Hypsipetes colonization of the western Indian Ocean from Asia within the last 2.6 Myr. The expansion of Hypsipetes appears to have occurred rapidly, with descendants found across the breadth of its western Indian Ocean range. The data suggest that a more recent expansion of Hypsipetes madagascariensis from Madagascar led to the colonization of Aldabra and a secondary colonization of the Comoros. Groupings of western Indian Ocean Hypsipetes according to phenotypic similarities do not correspond to mtDNA lineages, suggesting that these similarities have evolved by convergence or parallelism. The direction of phenotypic change cannot be inferred with confidence, since the primary expansion occurred rapidly relative to the rate of mtDNA substitution, and the colonization sequence remains uncertain. However, evidence from biogeography and comparison of independent colonization events are consistent with the persistence of a small grey continental bulbul in India and Madagascar, and multiple independent origins of large size and green plumage in insular island populations of the Comoros, Mascarenes and Seychelles. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 85, 271,287. [source] Simultaneous analysis of basal Hymenoptera (Insecta): introducing robust-choice sensitivity analysisBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2003SUSANNE SCHULMEISTER Molecular characters are analysed on their own and in combination with morphological data to examine the phylogenetic relationships of the basal lineages of Hymenoptera (,Symphyta'). This study covers 47 sawfly genera and nine apocritan families and includes molecular sequences from five genes , 12S, 16S, 18S and 28S ribosomal genes and cytochrome oxidase 1 , as well as 343 morphological characters. A robust-choice sensitivity analysis is performed with the data. First, the simultaneous analysis is repeated three times, each time employing a different step matrix for weighting the transformations of the molecular characters. Then, the results of all three simultaneous analyses are summarized in a strict consensus in order to avoid basing the conclusions on a narrow set of assumptions. This methodology is discussed in the paper. The relationships among superfamilies largely confirm previous hypotheses, being (Xyeloidea (Tenthredinoidea s.l. (Pamphilioidea (Cephoidea (Siricoidea (Xiphydrioidea (Orussoidea Apocrita))))))), where Siricoidea is understood as Siricidae+Anaxyelidae. However, the relationships within Tenthredinoidea s.s. proposed here are novel: ({Argidae Pergidae}[Athalia{(Diprionidae Cimbicidae) Tenthredinidae minus Athalia}]). © 2003 The Linnean Society of London. Biological Journal of the Linnean Society, 2003, 79, 245,275. [source] Phylogeny, biogeography and the stepwise evolutionary colonization of intertidal habitat in the Liparocephalini based on morphological and molecular characters (Coleoptera: Staphylinidae: Aleocharinae)CLADISTICS, Issue 4 2010Kee-Jeong Ahn A phylogenetic analysis of the tribe Liparocephalini Fenyes is presented based on morphological and molecular characters. The data set comprised 50 adult morphological characters, partial COI (907 bp), COII (366 bp) and 12S rDNA (325,355 bp), and nearly complete sequences of 18S rDNA (1768,1902 bp) for 21 species. Eighteen species of liparocephaline beetles from all eight genera and three outgroups, are included. The sequences were analysed separately and simultaneously with morphological characters by direct optimization in the program POY4 and by partitioned Bayesian analysis for the combined data. The direct optimization (DO) tree for the combined data under equal weighting, which also shows a minimum incongruence length difference value, resulted in a monophyletic Liparocephalini with the following patterns of phylogenetic relationships (outgroup ((Baeostethus, Ianmoorea) (Paramblopusa ((Amblopusa, Halorhadinus) (Liparocephalus, Diaulota))))). A sensitivity analysis using 16 different parameter sets for the combined data shows the monophyly of the liparocephalines and all its genera under all parameter sets. Bayesian analysis resulted in topological differences in comparison with the DO tree under equal weighting only in the position of the genus Paramblopusa and clade (Amblopusa + Halorhadinus), which were reversed. Historical biogeography and the stepwise evolutionary colonization of intertidal habitat in the Liparocephalini are discussed. Based on the biogeographical analyses, we hypothesize that the ancestor of the Liparocephalini occurred along the Panthallassan Ocean, the direct antecedent of the Pacific Ocean, followed by repeated dispersals to the Nearctic from the Palearctic. We also hypothesize that ancestors of the Liparocephalini appear to have arisen in the littoral zone of beaches and then colonized rocky reef areas in the low tidal zone later through high- to mid-tide zones. ,© The Willi Hennig Society 2009. [source] The role of wood anatomy in phylogeny reconstruction of EricalesCLADISTICS, Issue 3 2007Frederic Lens The systematic significance of wood anatomical characters within Ericales is evaluated using separate and combined parsimony analyses including 23 wood characters and 3945 informative molecular characters. Analyses of wood features alone result in poorly resolved and conflicting topologies. However, when pedomorphic character states are coded as inapplicable, the combined bootstrap topology results in an increase of resolution and support at most deeper nodes compared with the molecular analyses. This suggests that phylogenetic information from the limited number of morphological characters is not completely swamped by an overwhelming amount of molecular data. Based on the morphology of vessels and fibers, and the distribution of axial parenchyma, two major wood types can be distinguished within Ericales: (i) a "primitive" type, nearly identical to the wood structure in the more basal outgroup Cornales, which is likely to have persisted in one major clade, and (ii) a "derived" type that must have evolved in at least two separate evolutionary lines. The occurrence of the first type is strongly correlated with shrubs to small trees growing in cold temperate or tropical montane regions, while the second type is common in tall trees of tropical lowlands. This favors the inclusion of ecologically adaptive features in phylogeny reconstruction. © The Willi Hennig Society 2006. [source] | |||||||||||||