Sökning: "species concepts"

Visar resultat 1 - 5 av 64 avhandlingar innehållade orden species concepts.

  1. 1. Biologisk mångfald i läroböcker i biologi

    Författare :Maria Ferlin; Högskolan i Borås; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; textbooks; biological diversity; social semiotics; multimodality; meaning making; concept; species; species concept; Utbildningsvetenskap med inriktning mot naturvetenskap; Textbooks; Biological diversity; Social semiotics; Multimodality; Meaning making; Concept; Species; Species concept;

    Sammanfattning : The aim of this thesis is to analyse offered meaning, that is, what and how subject content is communicated to the recipients. In this case the subject content is biological diversity and the communicative artefacts are biology books for the latter grades in the Swedish compulsory school. LÄS MER

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

    Författare :Per Alström; Timothy M. Crowe; Uppsala universitet; []
    Nyckelord :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;

    Sammanfattning : 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). LÄS MER

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

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

    Sammanfattning : 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. LÄS MER

  5. 4. Comparative morphological studies of fossil and living plane trees (Platanaceae) and oaks (Quercus): taxonomy, ecology, evolution

    Författare :Georg Florian Tschan; Thomas Denk; Ove Eriksson; Bertil Ståhl; Stockholms universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

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

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

    Sammanfattning : 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. LÄS MER