Search for dissertations about: "species concepts"

Showing result 1 - 5 of 61 swedish dissertations containing the words species concepts.

  2. 1. Species Limits and Systematics in Some Passerine Birds

    Author : Per Alström; Timothy M. Crowe; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Organismic biology; Mirafra; Seicercus; Phylloscopus; Motacilla; species concepts; species limits; phylogeny; morphology; vocalisations; mitochondrial DNA; nuclear DNA; incongruence; Organismbiologi; Organism biology; Organismbiologi; systematisk zoologi; Systematic Zoology;

    Abstract : I use morphological, vocal, molecular, behavioural, ecological and distributional data to re-evaluate the systematics of three passerine bird groups, the Mirafraassamica complex (bush-larks), the genus Seicercus ("spectacled-warblers"; with emphasis on the the S. burkii complex) and the genus Motacilla (wagtails). 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. Comparative morphological studies of fossil and living plane trees (Platanaceae) and oaks (Quercus): taxonomy, ecology, evolution

    Author : Georg Florian Tschan; Thomas Denk; Ove Eriksson; Bertil Ståhl; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Platanaceae; Platanus; Credneria; Quercus; Galliferae; leaf architecture; epidermal anatomy; comparative morphology; character variation; variability; sample size; diversity patterns; species concepts; ecology; biogeography; evolution; plant fossils; Plant Ecology; växtekologi;

    Abstract : Morphological characters are essential for flowering plant identification, but also provide information about diversity patterns and ecological adaptation. In woody plant species, characters of the leaf are among the most useful and can be examined on fossils as well. READ MORE

  6. 4. Laser-based absorption spectrometry : development of NICE-OHMS towards ultra-sensitive trace species detection

    Author : Florian Schmidt; Ove Axner; Livio Gianfrani; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; absorption spectrometry; trace species detection; fiber laser; modulation; cavity-enhanced spectroscopy; optical saturation; laser frequency stabilization; free-spectral-range; Physics; Fysik;

    Abstract : Laser-based absorption spectroscopy (AS) is a powerful technique for qualitative and quantitative studies of atoms and molecules. An important field of use of AS is the detection of species in trace concentrations, which has applications not only in physics and chemistry but also in biology and medicine, encompassing environmental monitoring, regulation of industrial processes and breath analysis. READ MORE

  7. 5. The Concepts of Health, Well-being and Welfare as Applied to Animals : A Philosophical Analysis of the Concepts with the Regard to the Differences Between Animals

    Author : Henrik Lerner; Lennart Nordenfelt; Stefan Gunnarsson; David Fraser; Linköpings universitet; []
    Keywords : HUMANIORA; HUMANITIES; Concept; concept formation; welfare; definition; health; legislation; natural behaviour; role for animals; science of animal health and welfare; veterinary medicine; well-being; begrepp; begreppsbildning; definition; djurs roller; hälsa; lagstiftning; naturligt beteende; veterinärmedicin; välbefinnande; välfärd; Philosophy subjects; Filosofiämnen;

    Abstract : This thesis is an analysis of the use and definition of the concepts health, well-being and welfare within the field called “the science of animal health and welfare”. The materials used are a literature survey of the field, qualitative interviews with Swedish veterinary surgeons and a study of the concepts in legislation concerning animals in England, Germany and Sweden. READ MORE