Sökning: "zoologisk systematik och evolutionsforskning"

Visar resultat 21 - 25 av 28 avhandlingar innehållade orden zoologisk systematik och evolutionsforskning.

1. 21. Molecular phylogeny of tyrant flycatchers, cotingas, manakins and their allies (Aves: Tyrannida)

   Författare :Jan I. Ohlson; Per G. P. Ericson; Cristina Y. Miyaki; Stockholms universitet; []
   Nyckelord :Suboscines; Tyrannida; Tyrannidae; Cotingidae; Pipridae; South America; phylogeny; evolution; adaptive radiation; NATURAL SCIENCES; NATURVETENSKAP; Systematic Zoology; zoologisk systematik och evolutionsforskning;

   Sammanfattning : Tyrannida is a monophyletic clade that together with Furnariida constitutes the New World suboscines. The ca 560 species in Tyrannida are traditionally divided between three families: Tyrannidae (tyrant flycatchers), Cotingidae (cotingas) and Pipridae (manakins). LÄS MER

3. 22. Genetic structure, demographic change and extinction dynamics in the collared lemming and woolly mammoth

   Författare :Eleftheria Palkopoulou; Love Dalén; Richard Edward Green; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Systematic Zoology; zoologisk systematik och evolutionsforskning;

   Sammanfattning : In light of current climate change it is critical to understand how different species have been affected in the past by well-known climatic events. In this thesis, DNA was retrieved from ancient material to study the population dynamics of two cold-adapted taxa that capture the extremes of body size range in mammals: the collared lemming (Dicrostonyx sp. LÄS MER

4. 23. Genomic analysis of the process leading up to the extinction of the woolly mammoth

   Författare :Patrícia Pečnerová; Love Dalén; Mark Thomas; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; woolly mammoth; Mammuthus primigenius; extinction; Wrangel Island; ancient DNA; palaeogenetics; population genetics; genomics; genomic erosion; genetic drift; inbreeding; population size; Systematic Zoology; zoologisk systematik och evolutionsforskning;

   Sammanfattning : Species worldwide are subject to contractions in both abundance and geographical range, and their persistence in a changing environment may thus depend on the ability to survive in small and fragmented populations. Despite the urgent need to understand how extinction works, our knowledge of pre-extinction genetic processes is limited because techniques allowing population and conservation genomics to be studied in wild threatened populations have become available only recently. LÄS MER

5. 24. Hidden Creatures – systematics of the Euphorinae (Hymenoptera)

   Författare :Julia Stigenberg; Fredrik Ronquist; Johannes Bergsten; Andrew Austin; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Parasitic wasps; Braconidae; Euphorinae; systematics; phylogeny; molecular taxonomy; cryptic species; evolution; host preferences; identification keys; Systematic Zoology; zoologisk systematik och evolutionsforskning;

   Sammanfattning : Parasitic wasps constitute one of the last remaining frontiers in the charting of animal diversity. The Braconidae is the second most species-rich family of parasitic wasps; the world fauna has been estimated at 40 000 species and the Swedish fauna is believed to include a little more than 2 000 species, 1 200 of which are currently documented. LÄS MER

7. 25. Taking a Bite out of Diversity - Taxonomy and systematics of biting midges

   Författare :Jonas Strandberg; Kjell Arne Johanson; Urban Olsson; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ceratopogonidae; Dasyhelea; barcoding; COI; phylogeny Sweden; Forcipomyia; Bezzia; Palpomyia; Degen1; Systematic Zoology; zoologisk systematik och evolutionsforskning;

   Sammanfattning : 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. LÄS MER