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Träfflista för sökning "WFRF:(Johanson Kjell Arne Professor) "

Sökning: WFRF:(Johanson Kjell Arne Professor)

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1.
  • Wahlberg, Emma, 1981- (författare)
  • Molecules and morphology in Empidoidea (Diptera) : Phylogenetic analysis and taxonomical implications
  • 2020
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The classification and evolutionary history of the superfamily Empidoidea (Diptera) have been far from straightforward subjects. Morphology based phylogenies of the superfamily have been unable to answer many questions raised by both systematists and biogeographers, as well as ecologists and ethologists, partly due to morphological modifications and adaptations difficult to interpret. In paper I a phylogeny is presented which was the first published that was based on molecular data with multiple loci and with high support. We sampled several groups never included in molecular analyses before and were able to resolve several relationships and recover several species groups that were previously unplaced. Atelestidae is confirmed as the sister group to remaining families. Hybotidae is sister group to Dolichopodidae, Ragadidae stat. n. and Empididae. Species included in the family Brachystomatidae are found to be nested within Empididae and Brachystomatidae is therefore lowered to subfamily. The erection of Ragadidae to family, sister to Empididae, is based on genetic distances between the present families and subfamilies. Paper II deals with the genus Wiedemannia (Empididae: Clinocerinae), also using molecular data but also put into a spatial and temporal context with molecular dating. The subgenera are found to be non-monophyletic and are therefore suggested to be rejected as accepted names. The dated tree, based on molecular data and known fossil records, suggests an initial diversification 50 million years ago followed by further diversification events that may be linked to changes in sea levels on a global scale. We also provide a Species Distribution Model map suggesting areas of potential hot spots as based on climatic variables. Following the results in paper I, the internal relationships of Ragadidae are revised in paper III. The lack of DNA data, partly caused by few available specimens and the rarity of some species, motivated a morphological approach together with a maximum parsimony analysis to investigate the monophyly of species groups and genera. The flower feeding genera Iteaphila and Anthepiscopus are found to form a distinct monophyletic clade together with Hormopeza. The internal relationships are revised, updated diagnostic characters are provided as well as a determination key to the genera. In paper IV we deal with the taxonomical issue of Chvalaea sopianae and C. rugosiventris, two species in the family Hybotidae. Both species were originally described from single female specimens.  However, the sex of C. rugosiventris was mistaken in the original description, and the differential characters of the two species are based on sexual dimorphism. The two species are synonymized and the male of C. rugosiventris redescribed. We also provide additional geographic data on the hybotid species Allanthalia pallida and Leptodromiella crassiseta. The final paper, paper V, presents records of new species to Sweden and new records within Sweden of a large number of species of Hybotidae, Empididae and Ragadidae. We also provide a substantial addition of genetic barcodes of the Swedish fauna, shared publicly in The Barcode of Life Database. This increases the coverage of Swedish taxa in the database with 71% for Empididae and 13% for Hybotidae.
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2.
  • Hovmöller, Rasmus, 1975- (författare)
  • Molecular phylogenetics and taxonomic issues in dragonfly systematics (Insecta: Odonata)
  • 2006
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Dragonflies (Odonata) are one of the ancestral groups of extant insects. They represent one of the three most basal branches in the phylogeny of winged insects. The other two groups are the Ephemeroptera, mayflies, and Neoptera, the latter which covers the remaining winged insects. The first paper is about the phylogenetic position of Odonata in relation to the other basal insect clades using 18S and 28S rDNA sequences. It was demonstrated that there are under certain parameters a strong statistical support for a sister-group relationship between Odonata and Neoptera forming the group Palaeoptera. The second paper is about the phylogeny of the Holarctic dragonfly Leucorrhinia. Dragonfly larvae are frequently equipped with spines on the abdomen, with great variation in spinyness between species. From an analysis of sequences of ITS and 5.8S rDNA it was found that spines have been lost at least twice in Leucorrhinia, in the European L. rubicunda and again in a clade of North American species. The third paper is on the subfamily Ischnurinae (Odonata: Coenagrionidae), a group dominated by the two larger genera Ischnura and Enallagma along with several mono- or oligotypic genera. From the presented molecular study, using mitochondrial 16S rDNA and COII sequences, it is demonstrated that Ischnurinae, and Ischnura are monophyletic. Enallagma is not monophyletic, and the genus name Enallagma should be restricted to the E. cyathigerum clade. he fourth paper is a catalog of the genus Coenagrion, with full information on synonymy, type material and bibliographical data. The fifth paper is an appeal to the International Commission on Zoological Nomenclature to suppress the genus group name Agrion. The letter of appeal elucidates the priority of Agrion, and demonstrates why it has fallen out of use. A case if made for why Agrion should be placed on the list of unavailable names, and Calopteryx given full validity.
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3.
  • Strandberg, Jonas, 1983- (författare)
  • Taking a Bite out of Diversity - Taxonomy and systematics of biting midges
  • 2016
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The biting midges (family Ceratopogonidae) is one of the most species rich amongst the biting flies (Diptera) and has been recorded from most parts of the world. The species are mostly known for their capability to act as vectors for several important diseases, which have helped in shaping the focus to one of its genera, Culicoides Latreille, 1809. This thesis gives an overview of the knowledge of the Swedish diversity, in the first paper (paper I) with a closer look at the species of Dasyhelea Kieffer, 1911 where all twenty species found in Sweden are presented with their associated localities, and two new species are described.  In the second paper (paper II) the biting midge diversity of Sweden is presented based on specimens collected from several localities. All these individuals were barcoded using the mitochondrial cytochrome oxidase I gene (COI). The analysis included 773 specimens that were assigned into 214 barcoding clusters (BINs) and sorted into 164 groups based on their morphology. The third paper (paper III) broadens the scale were the evolutionary relationships within the family are investigated by applying five protein coding genes (COI, CAD, TPI, AATS and PGD) and specimens from different parts of the World. The analysis recovers Ceratopogonini, Forcipomyia Meigen, 1818 and Bezzia Kieffer, 1899 as paraphyletic and Palpomyia Meigen, 1818 polyphyletic. In the last and fourth paper (paper IV) the family is used as a model organism together with Hymenoptera for an alternative analysis method for reducing the impact of saturation and long-branch attraction using non-synonymous coding (e.g. Degen1) on only parts of a dataset. The effectiveness of the method is compared to the removal of the faster evolving third codon position. The result yields a higher number of supported nodes as well as a higher median of support for the method as well as an ability to reduce long-branch attraction artifacts.
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