Phylogenetic relationships of the genus Cheilosia and the tribe Rhingiini (Diptera, Syrphidae) based on morphological and molecular characters

The phylogenetic relationships of the tribe Rhingiini and the genus Cheilosia (Diptera, Syrphidae) were investigated using morphological and molecular characters. The genus Cheilosia is one of the most diverse lineages of hoverflies (Syrphidae). The mitochondrial protein coding gene cytochrome c oxidase subunit I (COI), and the D2‐3 region of the nuclear 28S rRNA gene were chosen for sequencing, and morphological characters were scored for both adults and immature stages. The combined dataset included 56 ingroup taxa. The datasets were analyzed separately and in conjunction, using both static and dynamic alignment under the parsimony criterion. The aim of the study was to assess the phylogenetic relationships of the tribe Rhingiini, and to explore if the subgenera of Cheilosia were supported as monophyletic clades. Results showed that the monophyly of subtribes of Rhingiini remained ambiguous, especially due to unstable phylogenetic placements of the genera Portevinia and Rhingia. We recovered most subgenera of Cheilosia as monophyletic clades. Dynamic alignment, using the optimization alignment program POY, always recovered more parsimonious topologies under all parameter weighting schemes, than did parsimony analyses using static alignment and analyzed with NONA.     

Evolution of the major lineages of tapeworms (Platyhelminthes: Cestoidea) inferred from 18S ribosomal DNA and elongation factor-1alpha

The interrelationships of the tapeworms (Platyhelminthes: Cestoidea) were inferred by analysis of complete gene sequences (approximately 2,200 bp) of 18S small subunit ribosomal DNA (18S) and partial gene sequences (approximately 900 bp) of elongation factor-1alpha (Ef-1alpha). New collections were made of 23 species representing each of the 14 currently recognized orders of tapeworms, including the Amphilinidea, Gyrocotylidea, and the 12 orders of the Eucestoda. Sequences were determined directly from polymerase chain reaction (PCR) products by either manual or automated methods. Nucleotide sequences of platyhelminth species outside of the Cestoidea were obtained for rooting the resulting trees. The 18S sequences were aligned with reference to the secondary structural features of the gene and the Ef-1alpha sequences were aligned with reference to their corresponding amino acid residues. Significant length variation among taxa was observed in the V2, V4, and V7 variable regions of the 18S gene. Such positions where sequences could not be aligned confidently were excluded from the analyses. Third codon positions of the Ef-1alpha gene were inferred to be saturated at an ordinal level of comparison. In addition, a short (approximately 35 bp) intron region of the Ef-1alpha gene was found to be shared only among the eucestode taxa, with the exception of Spathebothrium simplex (Spathebothriidea), which lacked the intron. Complete alignments showing structural features of the genes and sites excluded from analysis are provided as appendices. The sequence data were partitioned into 7 data sets in order to examine the effects of analyses on different subsets of the data. Analyses were conducted on the 2 genes independently, different codon positions of Ef-1alpha, amino acid sequences of Ef-1alpha, and combinations thereof. All subsets of the data were analyzed under the criterion of maximum parsimony as well as minimum evolution using both maximum-likelihood estimated, and LogDet-transformed distances. Results varied among the different data partitions and methods of analysis. Nodes with strong character support, however, were consistently recovered, and a general pattern of evolution was observed. Monophyly of the Cestoidea (Amphilinidea + Gyrocotylidea + Eucestoda) and Eucestoda and the traditionally accepted positions of the Amphilinidea and Gyrocotylidea as sister lineages to the Eucestoda were supported. Within the Eucestoda, the Spathebothriidea was found to be the sister of all other eucestodes. The remaining orders generally formed a diphyletic pattern of evolution consisting of separate difossate and tetrafossate lineages. This pattern was not universally observed among the analyses, primarily because the trypanorhynch and diphyllidean taxa showed instability in their phylogenetic position. Additional relationships that showed high levels of nodal support included a sister relationship between the Pseudophyllidea and Haplobothriidea and a clade uniting the Cyclophyllidea, Nippotaeniidea, and Tetrabothriidea. The Tetraphyllidea, as currently defined, was found to be paraphyletic without the inclusion of the orders Proteocephalidea and, possibly, Lecanicephalidea. Ordinal status of a monophyletic Litobothriidea, currently classified within the Tetraphyllidea, was found to be supported from a phylogenetic perspective.     

基于16S rDNA和28S rDNA D2基因序列与形态特征联合分析的中国角顶叶蝉亚科系统发育研究（半翅目： 叶蝉科）

首次在国内利用28S rDNA D2区段和16S rDNA基因序列,结合50个形态特征对角顶叶蝉亚科(Deltocephalinae)［半翅目（Hemiptera）: 叶蝉科（Cicadellidae）］19个属进行系统发育分析研究。从无水乙醇浸泡保存的标本中提取基因组DNA并扩增了19个内群和1种外群Typhlocybinae［半翅目(Hemiptera): 叶蝉科(Cicadellidae)］种类的28S rDNA D2基因片段并测序,同时扩增了16S rDNA基因片段并测序11条,采用了GenBank中1个种类的16S rDNA同源序列。采用PAUP*4.0和MrBayes3.0两个分析软件和3种建树方法,利用同源28S D2 rDNA和16S rDNA两个基因序列与形态特征结合进行系统发育分析研究。分析结果表明,二叉叶蝉族Macrostelini是一个单系,并在角顶叶蝉亚科的系统发育中处于基部的位置,是内群中最原始的族;角顶叶蝉族Deltocephalini中除了纹翅叶蝉属Nakaharanus,其余各属构成单系;殃叶蝉族Euscelini内属的归属比较混乱,可能是一个并系群,属间差异有待进一步研究。隆额叶蝉族Paralimnini与顶带叶蝉族Athysanini是姐妹群。带叶蝉属Scaphoideus与纹翅叶蝉属Nakaharanus是姐妹群,二者与木叶蝉属Phlogotettix的关系最近,三者构成一个单系,建议将三者归为带叶蝉族Scaphoideini。研究结果还表明,小眼叶蝉族Xestocephalini和Balcluthini的系统发育位置不明,有待进一步研究。     

On the systematics of the fungus gnat subfamily Mycetophilinae (Diptera): a combined morphological and molecular approach

The phylogenetic relationships within the fungus gnat subfamily Mycetophilinae (Diptera) are addressed using a combined morphological and molecular approach. Twenty-four species, representing nine genera of the tribe Mycetophilini and 15 genera of the tribe Exechiini, were included in the study. Analyses include nucleotide sequences of mitochondrial (cytochrome oxidase I and 16S), and nuclear (18S and 28S rDNA) genes, in addition to 65 morphological characters. A combined parsimony analysis, including all characters, supports the monophyly of the subfamily Mycetophilinae and two of its tribes, Exechiini and Mycetophilini. There is also statistical support for a Mycetophila- group and a Phronia- group within the tribe Mycetophilini. The Phronia- group includes the genera Phronia , Macrobrachius and Trichonta . The Mycetophila- group includes the genera Mycetophila , Epicypta , Platurocypta , Sceptonia and Zygomyia . A Bayesian analysis based on the nucleotide sequences alone also support these clades within Mycetophilini except for the position of Dynatosoma which is recovered as the sister taxon to the Phronia- group. A somewhat different pattern, however, is observed for the tribe Exechiini – neither molecular data nor the combined data set support unambiguously any intergeneric relationships within Exechiini.     

Phylogenetic relationships of Steinernema Travassos, 1927 (Nematoda: Cephalobina: Steinernematidae) based on nuclear, mitochondrial and morphological data

Entomopathogenic nematodes of the genus Steinernema are lethal parasites of insects that are used as biological control agents of several lepidopteran, dipteran and coleopteran pests. Phylogenetic relationships among 25 Steinernema species were estimated using nucleotide sequences from three genes and 22 morphological characters. Parsimony analysis of 28S (LSU) sequences yielded a well-resolved phylogenetic hypothesis with reliable bootstrap support for 13 clades. Parsimony analysis of mitochondrial DNA sequences (12S rDNA and cox 1 genes) yielded phylogenetic trees with a lower consistency index than for LSU sequences, and with fewer reliably supported clades. Combined phylogenetic analysis of the 3-gene dataset by parsimony and Bayesian methods yielded well-resolved and highly similar trees. Bayesian posterior probabilities were high for most clades; bootstrap (parsimony) support was reliable for approximately half of the internal nodes. Parsimony analysis of the morphological dataset yielded a poorly resolved tree, whereas total evidence analysis (molecular plus morphological data) yielded a phylogenetic hypothesis consistent with, but less resolved than trees inferred from combined molecular data. Parsimony mapping of morphological characters on the 3-gene trees showed that most structural features of steinernematids are highly homoplastic. The distribution of nematode foraging strategies on these trees predicts that S. hermaphroditum, S. diaprepesi and S. longicaudum (US isolate) have cruise forager behaviours.     

Phylogenetic relationships of Steinernema Travassos, 1927 (Nematoda: Cephalobina: Steinernematidae) based on nuclear, mitochondrial and morphological data

Entomopathogenic nematodes of the genus Steinernema are lethal parasites of insects that are used as biological control agents of several lepidopteran, dipteran and coleopteran pests. Phylogenetic relationships among 25 Steinernema species were estimated using nucleotide sequences from three genes and 22 morphological characters. Parsimony analysis of 28S (LSU) sequences yielded a well-resolved phylogenetic hypothesis with reliable bootstrap support for 13 clades. Parsimony analysis of mitochondrial DNA sequences (12S rDNA and cox 1 genes) yielded phylogenetic trees with a lower consistency index than for LSU sequences, and with fewer reliably supported clades. Combined phylogenetic analysis of the 3-gene dataset by parsimony and Bayesian methods yielded well-resolved and highly similar trees. Bayesian posterior probabilities were high for most clades; bootstrap (parsimony) support was reliable for approximately half of the internal nodes. Parsimony analysis of the morphological dataset yielded a poorly resolved tree, whereas total evidence analysis (molecular plus morphological data) yielded a phylogenetic hypothesis consistent with, but less resolved than trees inferred from combined molecular data. Parsimony mapping of morphological characters on the 3-gene trees showed that most structural features of steinernematids are highly homoplastic. The distribution of nematode foraging strategies on these trees predicts that S. hermaphroditum, S. diaprepesi and S. longicaudum (US isolate) have cruise forager behaviours.     

A phylogenetic analysis of tribe Areceae (Arecaceae) using two low-copy nuclear genes

 A phylogenetic study of the largest tribe of palms, the Areceae, was conducted using sequences of two low-copy nuclear genes. Previous morphological and plastid DNA studies have not supported the monophyly of the tribe, but have placed its members in a large clade that includes the monophyletic tribes Geonomeae, Cocoeae, Podococceae, and Hyophorbeae. We analyzed this large clade to test the monophyly of tribe Areceae with nuclear data, to explore relationships among its subtribes, and to identify other monophyletic groups. For 54 palm species, including members of all 17 subtribes of tribe Areceae, we sequenced regions of the malate synthase (MS) and phosphoribulokinase (PRK) genes. Simultaneous analysis of these regions revealed 52 shortest trees, all of which resolved tribe Areceae as polyphyletic. Subtribes Iguanurinae, Dypsidinae, Oncospermatinae, and Arecinae were also resolved as polyphyletic. A clade of Indo-Pacific taxa was resolved with strong support, and would be a suitable target for more focused study. Received February 7, 2001; accepted April 9, 2002 Published online: December 3, 2002     

Phylogenetic relationships of the tribe Paini (Amphibia, Anura, Ranidae) based on partial sequences of mitochondrial 12s and 16s rRNA genes

Partial sequences of mitochondrial 12S and 16S rRNA genes from 19 Asian frog species of the tribe Paini (Ranidae, Dicroglossinae) allowed a first molecular study of the phylogenetic relationships of this tribe. This analysis confirmed that this tribe is a monophyletic group, but suggested relationships did not agree with previous generic classification of this clade based on morphology. Two major clades were recognized within the Paini. For one of them, the generic name Quasipaa is available. Phylogenetic relationships within the other group are not yet fully clarified and need further study.     

Phylogeny and evolution of butterflies of the genus Parnassius: inferences from mitochondrial 16S and ND1 sequences

Phylogenetic relationships among species of the genus Parnassius and its related taxa were analyzed by comparing nucleotide sequences of mitochondrial 16S ribosomal RNA (504 sites) and NADH-dehydrogenase subunit 1 (469 sites). In the phylogenetic trees, Parnassius was found to be most closely related to Hypermnestra helios, whereas Archon apollinus, which has been classified in the tribe Parnassiini together with Parnassius and Hypermnestra, was more closely related to members of the tribe Zerynthiini. Within the Parnassius clade, six major clades corresponding to species groups were well supported, although the phylogenetic relationships among them were not clear. Although the results of the present study were in agreement with those of a previous phylogenetic study based on mitochondrial NADH-dehydrogenase subunit 5 sequences, our study strongly supported a close relationship between Parnassius and Hypermnestra, which was not well supported in the previous study.     

Pollen and the Evolution of Arctotideae (Compositae)

Recent molecular studies have elucidated the phylogeny of Compositae tribe Arctotideae, and found it to contain two, well supported, monophyletic subtribes, Arctotidineae and Gorteriinae, as well as some polyphyletic and problematic genera. On the basis of this new information, it may now be possible to identify diagnostic characters and synapomorphies to support the groupings defined within Arctotideae. Pollen characters have been shown to be particularly variable in Compositae. This paper aims to investigate the utility of those characters in the context of recent molecular phylogenies, in order to determine synapomorphic and diagnostic characters in Arctotideae. The pollen of each genus is described, illustrated with scanning electron micrographs, and optimised on a phylogeny of the tribe. Many pollen characters were found to be very informative when considered in the context of the current best estimate of phylogenetic relationships. Pollen morphology provides synapomorphies for clades at a number of hierarchical levels within Arctotideae, including the two subtribes, Arctotidinae and Gorteriinae, the grouping of Eremothamnus and Hoplophyllum, and smaller clades. It also supports the exclusion of Platycarpha from the tribe. The plesiomorphic palynological state for the tribe is discussed. Particular attention is paid to the evolution of different patterns of lophae (surface ridges). A single origin for the lophate condition is proposed as the most parsimonious mode of evolution in Arctotideae.     

Single-copy nuclear genes recover cretaceous-age divergences in bees

We analyzed the higher level phylogeny of the bee family Halictidae based on the coding regions of three single-copy nuclear genes (long-wavelength [LW] opsin, wingless, and elongation factor 1-alpha [EF-1 alpha]). Our combined data set consisted of 2,234 aligned nucleotide sites (702 base pairs [bp] for LW opsin, 405 bp for wingless, and 1,127 bp for EF-1 alpha) and 779 parsimony-informative sites. We included 58 species of halictid bees from 33 genera, representing all subfamilies and tribes, and rooted the trees using seven outgroups from other bee families: Colletidae, Andrenidae, Melittidae, and Apidae. We analyzed the separate and combined data sets by a variety of methods, including equal weights parsimony, maximum likelihood, and Bayesian methods. Analysis of the combined data set produced a strong phylogenetic signal with high bootstrap and Bremer support and high posterior probability well into the base of the tree. The phylogeny recovered the monophyly of the Halictidae and of all four subfamilies and both tribes, recovered relationships among the subfamilies and tribes congruent with morphology, and provided robust support for the relationships among the numerous genera in the tribe Halictini, sensu Michener (2000). Using our combined nucleotide data set, several recently described halictid fossils from the Oligocene and Eocene, and recently developed Bayesian methods, we estimated the antiquity of major clades within the family. Our results indicate that each of the four subfamilies arose well before the Cretaceous-Tertiary boundary and suggest that the early radiation of halictid bees involved substantial African-South American interchange roughly coincident with the separation of these two continents in the late Cretaceous. This combination of single-copy nuclear genes is capable of recovering Cretaceous-age divergences in bees with high levels of support. We propose that LW opsin, wingless, and EF-1 alpha(F2 copy) may be useful in resolving relationships among bee families and other Cretaceous-age insect lineages.     

Phylogenetic signal and the utility of 12S and 16S mtDNA in frog phylogeny

Genes selected for a phylogenetic study need to contain conserved information that reflects the phylogenetic history at the specific taxonomic level of interest. Mitochondrial ribosomal genes have been used for a wide range of phylogenetic questions in general and in anuran systematics in particular. We checked the plausibility of phylogenetic reconstructions in anurans that were built from commonly used 12S and 16S rRNA gene sequences. For up to 27 species arranged in taxon sets of graded inclusiveness, we inferred phylogenetic hypotheses based on different a priori decisions, i.e. choice of alignment method and alignment parameters, including/excluding variable sites, choice of reconstruction algorithm and models of evolution. Alignment methods and parameters, as well as taxon sampling all had notable effects on the results leading to a large number of conflicting topologies. Very few nodes were supported in all of the analyses. Data sets in which fast evolving and ambiguously aligned sites had been excluded performed worse than the complete data sets. There was moderate support for the monophyly of the Discoglossidae, Pelobatoidea, Pelobatidae and Pipidae. The clade Neobatrachia was robustly supported and the intrageneric relationships within Bombina and Discoglossus were well resolved indicating the usefulness of the genes for relatively recent phylogenetic events. Although 12S and 16S rRNA genes seem to carry some phylogenetic signal of deep (Mesozoic) splitting events the signal was not strong enough to resolve consistently the inter‐relationships of major clades within the Anura under varied methods and parameter settings.     

Using RAD seq for reconstructing phylogenies of highly diverged taxa: A test using the tribe Scandiceae (Apiaceae)

The angiosperm Apiaceae tribe Scandiceae includes four major clades—subtribes Daucinae, Ferulinae, Torilidinae, and Scandicinae—that originated ca. 20 Mya. Although all four subtribes are highly supported in molecular analyses, and morphological data indicate a sister relationship between Daucinae and Torilidinae, their branching order has not been resolved using standard Sanger multilocus data. Therefore, in this study, we test the utility of genomic RAD seq data in resolving deep phylogenetic relationships (up to 20 Mya) in Apiaceae subfamily Apioideae, with special emphasis on tribe Scandiceae using 12 representative species. We used two bioinformatic pipelines, pyRAD and RADIS (based on STACKS), to assemble RAD seq data and we tested the influence of various combinations of parameters on the robustness of the inferred tree topologies. Although different data processing approaches produced alignments with various amounts of missing data, they converged to two well‐supported topologies, irrespective of the phylogenetic method applied. Highly supported trees showed Scandicinae as sister to all other clades and indicated that Daucinae and Torilidinae are sister groups, thus confirming the relationship inferred from morphology. We conclude that the RAD seq method can be successfully used to resolve deep relationships formed 20 Mya within Apiaceae. We provide recommendations for parameter settings in RADIS and pyRAD for the analysis of taxa that have accumulated considerable genomic divergence.     

Phylogeny of the treehoppers (Insecta: Hemiptera: Membracidae): evidence from two nuclear genes

We present a molecular systematic investigation of relationships among family-group taxa of Membracidae, comprising nearly 3.5 kb of nucleotide sequence data from the nuclear genes elongation factor-1alpha (EF-1alpha: 958 bp) and 28S ribosomal DNA (28S rDNA: 2363 bp); data partitions are analyzed separately and in combination for 79 taxa. Analysis of the combined sequence data provided a better-resolved and more robust hypothesis of membracid phylogeny than did separate analyses of the individual genes. Results support the monophyly of the family Membracidae and indicate the presence of two major lineages (Centrotinae + Stegaspidinae + Centrodontinae and Darninae + Membracinae + Smiliinae). Within Membracidae, molecular data support the following assertions: (1) the previously unplaced genera Antillotolania and Deiroderes form a monophyletic group with Microcentrini; (2) Centrodontini and Nessorhinini are monophyletic clades that arise independently from within the Centrotinae; (3) Centrotinae is paraphyletic with respect to Centrodontinae; (4) the subfamily Membracinae is monophyletic and possibly allied with the darnine tribe Cymbomorphini; (5) the subfamily Darninae is paraphyletic; (6) the subfamily Smiliinae is paraphyletic, with molecular evidence indicating the exclusion of Micrutalini and perhaps Acutalini and Ceresini; and (7) Membracidae arose and diversified in the New World with multiple subsequent colonizations of the Old World. Our phylogenetic results suggest that morphology-based classifications of the Membracidae need to be reevaluated in light of emerging molecular evidence.     

Sensitivity of Ribosomal RNA Character Sampling in the Phylogeny of Rhabditida

Near-full-length 18S and 28S rRNA gene sequences were obtained for 33 nematode species. Datasets were constructed based on secondary structure and progressive multiple alignments, and clades were compared for phylogenies inferred by Bayesian and maximum likelihood methods. Clade comparisons were also made following removal of ambiguously aligned sites as determined using the program ProAlign. Different alignments of these data produced tree topologies that differed, sometimes markedly, when analyzed by the same inference method. With one exception, the same alignment produced an identical tree topology when analyzed by different methods. Removal of ambiguously aligned sites altered the tree topology and also reduced resolution. Nematode clades were sensitive to differences in multiple alignments, and more than doubling the amount of sequence data by addition of 28S rRNA did not fully mitigate this result. Although some individual clades showed substantially higher support when 28S data were combined with 18S data, the combined analysis yielded no statistically significant increases in the number of clades receiving higher support when compared to the 18S data alone. Secondary structure alignment increased accuracy in positional homology assignment and, when used in combination with paired-site substitution models, these structural hypotheses of characters and improved models of character state change yielded high levels of phylogenetic resolution. Phylogenetic results included strong support for inclusion of Daubaylia potomaca within Cephalobidae, whereas the position of Fescia grossa within Tylenchina varied depending on the alignment, and the relationships among Rhabditidae, Diplogastridae, and Bunonematidae were not resolved.     

a molecular phylogeny of apiaceae subfamily Apioideae: evidence from nuclear ribosomal DNA internal transcribed spacer sequences

Phylogenetic relationships among 40 New World and Old World members of Apiaceae subfamily Apioideae, representing seven of the eight tribes and eight of the ten subtribes commonly recognized in the subfamily, were inferred from nucleotide sequence variation in the internal transcribed spacer (ITS) regions of 18-26S nuclear ribosomal DNA. Although the sequences are alignable, with only 11% of sites excluded from the analyses because of alignment ambiguity, divergence values in pairwise comparisons of unambiguous positions among all taxa were high and ranged from 0.5 to 33.2% of nucleotides in ITS 1 and from 0 to 33.2% of nucleotides in ITS 2. Average sequence divergence across both spacer regions was 18.4% of nucleotides. Phylogenies derived from ITS sequences estimated using neighbor-joining analysis of substitution rates, and maximum likelihood and parsimony methods give trees of essentially similar topology and indicate that: (1) there is little support for any existing system of classification of the subfamily that is based largely on morphological and anatomical features of the mericarp; (2) there is a major phylogenetic division within the subfamily, with one clade comprising the genus Smyrnium and those taxa belonging to Drude's tribes Dauceae, Scandiceae, and Laserpitieae and the other clade comprising all other examined taxa; and (3) the genera Arracacia, Coaxana, Coulterophytum, Enantiophylla, Myrrhidendron, Prionosciadium, and Rhodosciadium, all endemic to Mexico and Central America, comprise a clade but their relationships to other New World taxa are equivocal. A phylogeny derived from parsimony analysis of chloroplast DNA rpoC1 intron sequences is consistent with, but considerably less resolved than, relationships derived from these ITS regions. This study affirms that ITS sequences are useful for phylogenetic inference among closely related members of Apioideae but, owing to high rates of nucleotide substitution, are less useful in resolving relationships among the more ancestral nodes of the phylogeny.     

A phylogenetic analysis of the Orchidaceae: evidence from rbcL nucleotide

Cladistic parsimony analyses of rbcL nucleotide sequence data from 171 taxa representing nearly all tribes and subtribes of Orchidaceae are presented here. These analyses divide the family into five primary monophyletic clades: apostasioid, cypripedioid, vanilloid, orchidoid, and epidendroid orchids, arranged in that order. These clades, with the exception of the vanilloids, essentially correspond to currently recognized subfamilies. A distinct subfamily, based upon tribe Vanilleae, is supported for Vanilla and its allies. The general tree topology is, for the most part, congruent with previously published hypotheses of intrafamilial relationships; however, there is no evidence supporting the previously recognized subfamilies Spiranthoideae, Neottioideae, or Vandoideae. Subfamily Spiranthoideae is embedded within a single clade containing members of Orchidoideae and sister to tribe Diurideae. Genera representing tribe Tropideae are placed within the epidendroid clade. Most traditional subtribal units are supported within each clade, but few tribes, as currently circumscribed, are monophyletic. Although powerful in assessing monophyly of clades within the family, in this case rbcL fails to provide strong support for the interrelationships of the subfamilies (i.e., along the spine of the tree). The cladograms presented here should serve as a standard to which future morphological and molecular studies can be compared.     

Relationships of the temperate Australasian labrid fish tribe Odacini (Perciformes; Teleostei)

The labrid tribe Odacini comprises four genera and 12 species of fishes that inhabit shallow kelp forest and seagrass areas in temperate waters of Australia and New Zealand. Odacines are morphologically disparate, but share synapomorphies in fin structure and fusion of teeth into a beak-like oral jaw. A phylogenetic analysis of odacines was conducted to investigate their relationships to other labrid fishes, the relationships of species within the tribe, and the evolution of herbivory within the group. Fragments from two mitochondrial genes, 12S rDNA and 16S rDNA, and two nuclear genes, Tmo4C4 and RAG2, were sequenced for seven odacine species (representing all four genera), eight species representing the other major labrid lineages, and three outgroup species. Maximum likelihood and maximum parsimony analyses on the resulting 2338 bp of DNA sequence produced nearly identical topologies differing only in the placement of a clade containing the cheiline Cheilinus fasciatus and the scarine Cryptotomus roseus. The remaining clades received strong bootstrap support under maximum parsimony, and all clades in the maximum likelihood analysis received high bootstrap proportions and high posterior probabilities. The hypsigenyine labrid Choerodon anchorago formed the sister group to the odacines. Within the odacines, Odax cyanoallix+Odax pullus formed the sister to the remaining odacines, with Odax acroptilus, Odax cyanomelas, and Siphonognathus argyrophanes forming successively closer sister groups to the clade Haletta semifasciatus+Neoodax balteatus. Either herbivory evolved twice in the odacines, or herbivory evolved once with two reversions to carnivory. The latter hypothesis appears more likely in the light of odacine feeding biology.     

Molecular phylogeny of Fordini (Hemiptera: Aphididae: Pemphiginae) inferred from nuclear gene EF-1 alpha and mitochondrial gene COI

The tribe Fordini is a fascinating group because of its complicated life history, primary host specificity and gall-forming characteristic. Different species produce galls with different morphology on different parts of the host plants. The EF-1alpha-based, COI-based and combined sequences-based phylogenetic trees with three algorithms MP, ML and Bayes all strongly suggest that Fordini is a monophyletic group with two clades corresponding to two subtribes, Fordina and Melaphidina, each also monophyletic. Some important morphological characters and primary host plants of aphids were mapped onto the phylogenetic tree to analyse the division of subtribes and to uncover at which level the aphids correspond to their primary hosts, Pistacia and Rhus. Results suggest that the division of subtribes in Fordini is closely related to host selection of aphids. The evolution of gall morphology and the probable driving force behind it in this tribe were also discussed. The Fordini aphids seem to have evolved towards a better ability to manipulate their host plant, induce strong sinks and gain high reproductive success. Galls in this tribe evolved mainly along two directions to attain this goal: (i) by enlarging the gall from small bag to spherical, even big cauliflower-like, and changing the galls' location or forming two galls in their life cycle (Fordina); (ii) by moving the gall position from midrib, petiole of the leaflet, and eventually to the common petiole of the compound leaf (Melaphidina).