Sökning: "diversification"

Visar resultat 16 - 20 av 260 avhandlingar innehållade ordet diversification.

1. 16. Microbial evolution: patterns of diversity in aquatic protists

   Författare :Ramiro Logares; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; dinoflagellates; biodiversity; lakes; Evolution; diversification; microbes; biogeography;

   Sammanfattning : Little is known about how microbes diversify in nature. In contrast to the more studied multicellular organisms, microbes can have a) huge population sizes, b) high reproductive rates and c) long-distance dispersal. These characteristics can affect their tempo and mode of diversification in ways that still need to be understood. LÄS MER

3. 17. Adaptive evolution in multidimensional trait spaces

   Författare :Paula Vasconcelos; Claus Rüffler; Maria Servedio; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; adaptive dynamics; mutidimensional trait spaces; evolutionary dynamics; disruptive selection; resource competition; diversification;

   Sammanfattning : Negative frequency-dependent disruptive selection, which arises due to the interplay between organisms of a population and their environment, is an important element driving phenotypic diversification and even speciation. Such selection regime can result from frequency- and density-dependent interactions between the organisms and their environment, so that the fitness landscape itself changes as the population evolves. LÄS MER

4. 18. Managing Value Creation and Appropriation

   Författare :Joakim Björkdahl; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Strategy; ICT; Innovation; Value creation; Manufacturing companies; Diversification; Business model; Value appropriation; Competencies;

   Sammanfattning : This thesis investigates how large Swedish manufacturing companies try to create value and appropriate financial returns by renewing their product offerings through the integration of Information and Communication Technologies (ICTs) in their established product categories, and the related challenges and opportunities this produces.While much attention has been given to the technology dimension of diversification, the economic and commercial domains have been rather ignored in the literature. LÄS MER

5. 19. Evolution of Lycopodiaceae (Lycopsida) : Relationships and Patterns of Diversification

   Författare :Niklas Wikström; Anders Tehler; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; systematisk botanik; Systematic Botany;

   Sammanfattning : A series of phylogenetic analyses using nucleotide sequence data resolves many aspects of the relationships in a group of land plants that until now have received comparatively little attention, the homosporous lycopsids or Lycopodiaceae. Although the group has evolved as an isolated lineage ever since the Late Devonian (more than 470 Myr ago), little is known about how modern species diversity relate to this ancient history. LÄS MER

7. 20. Species Limits, and Evolutionary History of Glassfrogs

   Författare :Santiago Castroviejo-Fisher; Carles Vilà; Jennifer A. Leonard; Miguel Vences; Uppsala universitet; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER