3,610 research outputs found
Mitochondrial DNA signature for range-wide populations of Bicyclus anynana suggests a rapid expansion from recent refugia
This study investigates the genetic diversity, population structure and demographic history of the afrotropical butterfly Bicyclus anynana using mitochondrial DNA (mtDNA). Samples from six wild populations covering most of the species range from Uganda to South Africa were compared for the cytochrome c oxidase subunit gene (COI). Molecular diversity indices show overall high mtDNA diversity for the populations, but low nucleotide divergence between haplotypes. Our results indicate relatively little geographic population structure among the southern populations, especially given the extensive distributional range and an expectation of limited gene flow between populations. We implemented neutrality tests to assess signatures of recent historical demographic events. Tajima's D test and Fu's FS test both suggested recent population growth for the populations. The results were only significant for the southernmost populations when applying Tajima's D, but Fu's FS indicated significant deviations from neutrality for all populations except the one closest to the equator. Based on our own findings and those from pollen and vegetation studies, we hypothesize that the species range of B. anynana was reduced to equatorial refugia during the last glacial period, and that the species expanded southwards during the past 10.000 years. These results provide crucial background information for studies of phenotypic and molecular adaptation in wild populations of B. anynan
Microgastrinae (Hymenoptera: Braconidae) parasitizing Epirrita autumnata (Lepidoptera: Geometridae) larvae in Fennoscandia with description of Cotesia autumnatae Shaw, sp. n.
The microgastrine subset of hymenopteran parasitoids of the geometrid Epirrita
autumnata is investigated in Fennoscandia. Ecology, including population dynamics,
of the moth has been intensively studied in northern and mountainous
Finland, Norway and Sweden. Recently supported hypotheses about the causes
of its cyclic population dynamics stress the role of parasitoids, while the
parasitoid complex with some 15 species is insufficiently known. The complex
includes four solitarymicrogastrine species, Protapanteles anchisiades (Nixon),
P. immunis (Wesmael), Cotesia salebrosa (Marshall) and C. autumnatae Shaw,
sp. n. Here, we provide detailed figures for the latter, which is morphologically
close to C. jucunda (Marshall), and describe the species as new to science. We
also providemore general habitus figures of the other three species, as well as an
identification key for the four species, aiming to aid recognition of these species
by ecologists dealingwithmicrogastrine parasitoids of E. autumnata and their alternative
geometrid hosts
The identity of the Finnish Osmoderma (Coleoptera: Scarabaeidae, Cetoniinae) population established by COI sequencing
The hermit beetle Osmoderma eremita (Coleoptera: Scarabaeidae) is a flagship species for invertebrate conservation efforts by the European Union. This taxon has recently been revealed as a species complex likely encompassing five cryptic species. The northernmost population of Osmoderma is found on the island of Ruissalo in Turku, Finland. This population has been protected as species 0. eremita, but its true species affinity has never been established. To resolve its identity, we sequenced the mitochondrial COI gene from seven specimens sampled in Ruissalo. Based on a phylogenetic hypothesis generated from the sequences combined with previously published data, the Finnish hermit beetle was identified as Osmoderma barnabita. Information regarding the ecology and life cycle of 0. eremita should then not uncritically be assumed to apply to the Finnish population. Rather, the Finnish population should be treated as a separate entity in conservation and management of European Osmoderma
The evolutionary history of Trichoptera (Insecta): A case of successful adaptation to life in freshwater
The insect order Trichoptera (caddisflies) forms the second most species-rich monophyletic group of animals in freshwater. So far, several attempts have been made to elucidate its evolutionary history with both morphological and molecular data. However, none have attempted to analyse the time frame for its diversification. The order is divided into three suborders - Annulipalpia, Integripalpia and Spicipalpia'. Historically, the most problematic taxon to place within the order is Spicipalpia', whose larvae do not build traditional cases or filtering nets like the majority of the caddisflies. They have previously been proposed to be the sister group of all other Trichoptera or more advanced within the order, with equivocal monophyly and with different interordinal placements among various studies. In order to resolve the evolutionary history of the caddisflies as well as timing their diversification, we utilized fragments of three nuclear (carbamoylphosphate synthethase, isocitrate dehydrogenase and RNA polymerase II) and one mitochondrial (cytochrome oxidase I) protein coding genes, with 16 fossil trichopteran taxa used for time calibration. The spicipalpian' families are recovered as ancestral to all other caddisflies, though paraphyletic. We recover stable relationships among most families and superfamilies, resolving many previously unrecognized phylogenetic affinities amongst extant families. The origin of Trichoptera is estimated to be around 234Ma, i.e. Middle - Late Triassic
The Qualified Legal Compliance Committee: Using the Attorney Conduct Rules to Restructure the Board of Directors
The Securities and Exchange Commission introduced a new corporate governance structure, the qualified legal compliance committee, as part of the professional standards of conduct for attorneys mandated by the Sarbanes-Oxley Act of 2002. QLCCs are consistent with the Commission\u27s general approach to improving corporate governance through specialized committees of independent directors. This Article suggests, however, that assessing the benefits and costs of creating QLCCs may be more complex than is initially apparent. Importantly, QLCCs are unlikely to be effective in the absence of incentives for active director monitoring. This Article concludes by considering three ways of increasing these incentives
Promocijas darbs
DarbÄ ir apkopota literatĆ«ra par furÄna un tiofÄna karbonilgrupas atvasinÄjumu, silatrÄnu un germatrÄnu iegĆ«ĆĄanas metodÄm. Tika sintezÄti aminosililgrupu saturoĆĄi furfurola dietilacetÄli, silÄ«ciju un germÄniju saturoĆĄi furÄna un tiofÄna karbonilsavienojumi, veiktas karbonilgrupas reakcijas un iegĆ«ti jauni furil(tienil)nitroni, -aldimÄ«ni, -laktoni, -metilÄn-bis-indoli, -ketoksÄ«mi, -O-alkil- ketoksÄ«mi, -1,5-benzodiazepÄ«ni. SintezÄti silatrÄni un bis-germatrÄni. SintezÄto savienojumu struktĆ«ras pierÄdÄ«tas ar spektrometriskajÄm metodÄm, izpÄtÄ«ta un salÄ«dzinÄta iegĆ«to vielu bioloÄŁiskÄ aktivitÄte. PerspektÄ«vÄkajÄm savienojumu klasÄm noteikta spÄja inhibÄt angioÄŁenÄzi un matricas metaloproteinÄzes.Synthesis of furane and thiophene carbonyl group containing derivatives, silatranes and germatranes have been reviewed. Were synthesized aminosilyl group containing furfurol diethylacetals, silicon and germanium containing furane and thiophene carbonyl compounds, performed carbonyl group reactions and obtained new furyl(thienyl)nitrones, -aldimines, -lactones, -methylene-bis-indoles, -ketoximes, -O-alkylketoximes, -1,5-benzodiazepines. Were synthesized silatranes and bis-germatranes. Structure of the synthesized compounds demonstrated by spectrometrical methods and studied and compared the biological activity of substances. For the most promising compounds a certain ability to inhibit angiogenesis and matrix metalloproteinase was determine
Environmentally driven extinction and opportunistic origination explain fern diversification patterns.
Combining palaeontological and neontological data offers a unique opportunity to investigate the relative roles of biotic and abiotic controls of species diversification, and the importance of origination versus extinction in driving evolutionary dynamics. Ferns comprise a major terrestrial plant radiation with an extensive evolutionary history providing a wealth of modern and fossil data for modelling environmental drivers of diversification. Here we develop a novel Bayesian model to simultaneously estimate correlations between diversification dynamics and multiple environmental trajectories. We estimate the impact of different factors on fern diversification over the past 400 million years by analysing a comprehensive dataset of fossil occurrences and complement these findings by analysing a large molecular phylogeny. We show that origination and extinction rates are governed by fundamentally different processes: originations depend on within-group diversity but are largely unaffected by environmental changes, whereas extinctions are strongly affected by external factors such as climate and geology. Our results indicate that the prime driver of fern diversity dynamics is environmentally driven extinction, with origination being an opportunistic response to diminishing ecospace occupancy
The microbiome of the Melitaea cinxia butterfly shows marked variation but is only little explained by the traits of the butterfly or its host plant
Understanding of the ecological factors that shape intraspecific variation of insect microbiota in natural populations is relatively poor. In Lepidopteran caterpillars, microbiota is assumed to be mainly composed of transient bacterial symbionts acquired from the host plant. We sampled Glanville fritillary (Melitaea cinxia) caterpillars from natural populations to describe their gut microbiome and to identify potential ecological factors that determine its structure. Our results demonstrate high variability of microbiota composition even among caterpillars that shared the same host plant individual and most likely the same genetic background. We observed that the caterpillars harboured microbial classes that varied among individuals and alternated between two distinct communities (one composed of mainly Enterobacteriaceae and another with more variable microbiota community). Even though the general structure of the microbiota was not attributed to the measured ecological factors, we found that phylogenetically similar microbiota showed corresponding responses to the sex and the parasitoid infection of the caterpillar and to those of the host plant's microbial and chemical composition. Our results indicate high among-individual variability in the microbiota of the M. cinxia caterpillar and contradict previous findings that the host plant is the major driver of the microbiota communities of insect herbivores.Peer reviewe
Next Generation Sequencing of Fecal DNA Reveals the Dietary Diversity of the Widespread Insectivorous Predator Daubenton's Bat (Myotis daubentonii) in Southwestern Finland
Understanding predator-prey dynamics is a fundamental task in the evaluation of the adaptive capacities of species. However, direct observations or morphological identification of fecal remains do not offer an effective way to study the dietary ecology of elusive species, such as nocturnal insectivorous bats. However, recent advances in molecular techniques have opened a new method for identifying prey species from fecal samples. In this study, we amplified species-specific mitochondrial COI fragments from fecal DNA extractions from 34 individual Daubenton's bats (Myotis daubentonii) collected between 2008 and 2010 from southwestern Finland. Altogether, 128 different species of prey were identified based on a comprehensive local DNA reference library. In our study area, Daubenton's bats feed most frequently on insects of the orders Diptera (found in the diet of 94% individuals), Trichoptera (69%) and Lepidoptera (63%). The most frequent dipteran family in the diet was Chironomidae, which was found in 31 of 34 individuals. Most common prey species were chironomids Microtendipes pedellus (found in 50% of bats), Glyptotendipes cauliginellus (44%), and Procladius ferrugineus (41%). For the first time, an accurate species level list of the diet of the insectivorous Daubenton's bat (Myotis daubentonii) in Finland is presented. We report a generally applicable method for describing the arthropod diet of vertebrate predators. We compare public databases to a national database to highlight the importance of a local reference database
'Species' from two different butterfly genera combined into one: description of a new genus of Euptychiina (Nymphalidae: Satyrinae) with unusually variable wing pattern
Sepona Freitas and Barbosa, gen. nov. is proposed for the Neotropical satyrine butterfly species Euptychia punctata Weymer, 1911 and its junior subjective synonyms Euptychia griseola Weymer, 1911 and Taygetis indecisa Ribeiro, 1931. The new genus has a distinctive wing pattern and shape of the valvae in the male genitalia, the latter being a unique autapomorphy within the subtribe Euptychiina. Based on molecular data, this genus is not sister to any other single euptychiine genus, instead appearing as the sister to all remaining genera in the Taygetis clade. The present paper illustrates the complexity of the taxonomy of Euptychiina, and the importance of using different sources of evidence in taxonomic studies. (C) 2016 Sociedade Brasileira de Entomologia. Published by Elsevier Editora Ltda
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