Search for dissertations about: "species"

Showing result 1 - 5 of 4844 swedish dissertations containing the word species.

2. 1. Species Aid : Organizational Sensemaking in a Preservation Project in Albania

   Author : Peter Green; Gudrun Dahl; Åsa Boholm; Stockholms universitet; []
   Keywords : HUMANIORA; HUMANITIES; Conservation; social anthropology; ecological anthropology; global environmental issues; Albania; sensemaking; organisational theory.; Cultural anthropology; Kulturantropologi;

   Abstract : In 1994 a Hungarian fisheries biologist specialised on sturgeons revealed that there was at least one population of sturgeons belonging to the threatened sturgeon species Ac. Naccari still present in the Albanian aquatic fauna. The stage was now set for an international conservation initiative. READ MORE

4. 2. Integrative taxonomy of birds : Studies into the nature, origin and delimitation of species

   Author : George Sangster; Per G. P. Ericson; Martin Päckert; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Aves; biogeography; integrative taxonomy; pluralism; ring species; speciation; species criteria; species limits; taxon chain; Systematic Zoology; zoologisk systematik och evolutionsforskning;

   Abstract : Species are the basic currency in biodiversity studies but what constitutes a species has long been controversial. A major breakthough was the insight that most systematists agree that species are segments of population lineages, and that multiple lines of evidence should be employed and integrated, a procedure called integrative taxonomy. READ MORE

5. 3. Through the magnifying glass - The big small world of marine meiofauna : Morphology, species and evolution in Nemertodermatida

   Author : Inga Meyer-Wachsmuth; Ulf Jondelius; Mark E Sidall; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Nemertodermatida; Acoelomorpha; morphology; CLSM; Phalloidin; musculature; DNA; cryptic species; species delimitation; dispersal; taxonomy; phylogenetics; IHC; nervous system; Systematic Zoology; zoologisk systematik och evolutionsforskning;

   Abstract : Nemertodermatida is a group of microscopic marine worm-like animals that live as part of the marine meiofauna in sandy or muddy sediments; one species lives commensally in a holothurian. These benthic worms were thought to disperse passively with ocean currents, resulting in little speciation and thus wide or even cosmopolitan distributions. READ MORE

6. 4. Species Limits, and Evolutionary History of Glassfrogs

   Author : Santiago Castroviejo-Fisher; Carles Vilà; Jennifer A. Leonard; Miguel Vences; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Amphibia; Anura; Biogeography; Centrolenidae; Diversification; Frogs; Molecular Phylogenetics; Neotropics; Pristimantis; Speciation; Species; Systematics; Taxonomy; Systematics and phylogenetics; Systematik och fylogeni; systematisk zoologi; Systematic Zoology;

   Abstract : Recognizing the mechanisms of speciation and the limits of species is essential to understand the origin of biodiversity and how to conserve it. The general aims of my investigations during my doctoral studies were two-fold: to study evolutionary patterns and processes, and to provide specific and superspecific taxonomic classifications that try to reflect evolutionary history. READ MORE

7. 5. Biodiversity and Species Extinctions in Model Food Webs

   Author : Charlotte Borrvall; Bo Ebenman; Owen Petchey; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; biodiversity; food webs; redundancy; relaxation time; stability; stochasticity; species deletion; species extinction; Biology; Biologi;

   Abstract : Many of the earth’s ecosystems are experiencing large species losses due to human impacts such as habitat destruction and fragmentation, climate change, species invasions, pollution, and overfishing. Due to the complex interactions between species in food webs the extinction of one species could lead to a cascade of further extinctions and hence cause dramatic changes in species composition and ecosystem processes. READ MORE