Sökning: "speciation rates"

Visar resultat 1 - 5 av 37 avhandlingar innehållade orden speciation rates.

1. 1. Biodiversity in Swedish Cyprinid Fish: Insights Into Processes of Divergence

   Författare :Marnie H Demandt; Mats Björklund; Erik Petersson; Brent Emerson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; speciation; hybridization; bottleneck; genetic drift; phylogeny; speciation rates; common bream; white bream; roach; Swedish cyprinid fish; Cyprinidae; Biology; Biologi;

   Sammanfattning : Uncovering and understanding the processes that have led to the biological diversity we observe today are of fundamental interest in biology. Since direct observation of speciation is usually impossible, knowledge about the processes behind species formation can be gathered by studying mutations, natural/sexual selection, and genetic drift. LÄS MER

3. 2. Mechanisms of speciation in Silene

   Författare :Xiaodong Liu; Sophie Karrenberg; Alex Buerkle; Uppsala universitet; []
   Nyckelord :speciation; reproductive isolation; Silene; ddRAD-seq; Biology with specialization in Evolutionary Genetics; Biologi med inriktning mot evolutionär genetik;

   Sammanfattning : A fundamental question in the field of evolutionary biology is how new species originate. Investigating speciation benefits from an integrated approach, which requires a solid understanding of ecology, reproductive biology, geographical distribution, underlying genetic architecture of reproductive isolation (RI), demographic history and genomic divergence. LÄS MER

4. 3. Conifer Evolution, from Demography and Local Adaptation to Evolutionary Rates : Examples from the Picea genus

   Författare :Jun Chen; Martin Lascoux; Ulf Lagercrantz; Matt Olson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Speciation; Demographics; clinal variation; convergent evolution; transcriptome; small regulatory RNA; Biologi med inriktning mot evolutionär funktionsgenomik; Biology with specialization in Evolutionary Functional Genomics; Biology with specialization in Evolutionary Genetics; Biologi med inriktning mot evolutionär genetik;

   Sammanfattning : Evolutionary process can be inferred at three different levels: the species level, the population level and the molecular level. In this thesis, I applied approaches at these three levels and aimed to get a comprehensive picture of conifer evolution, from speciation and demography to geographic variation and local adaptation, and then to the molecular evolution of proteins and small regulatory RNAs. LÄS MER

5. 4. Phylogenetic perspective on host plant use, colonization and speciation in butterflies

   Författare :Elisabet Weingartner; Sören Nylin; Niklas Wahlberg; Felix Sperling; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Oscillation hypothesis; speciation; Polygonia; Celastrina; Pararge; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; zoologisk ekologi; Animal Ecology;

   Sammanfattning : In this thesis we have studied speciation in three butterfly genera Polygonia (Nymphalidae, Nymphalini), Pararge (Nymphalidae, Satyrinae) and Celastrina (Lycaenidae: Polyommatinae). In the first paper a dated phylogeny, based on molecular data, of Polygonia was constructed. We found strong conflict between the nDNA and mtDNA datasets. LÄS MER

7. 5. Chemical Speciation of Sulfur and Metals in Biogas Reactors : Implications for Cobalt and Nickel Bio-uptake Processes

   Författare :Sepehr Shakeri Yekta; Bo Svensson; Ulf Skyllberg; Åsa Danielsson; Charles Banks; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Biogas; Anaerobic digestion; Chemical speciation; bio-uptake; Sulfur; Iron; Cobalt; Nickel; Biogas; Anaerob nedbrytning; Kemisk speciering; Bio-upptag; Svavel; Järn; Kobolt; Nickel;

   Sammanfattning : A balanced supply of micronutrients, including metals such as iron (Fe), cobalt (Co), and nickel (Ni), is required for the efficient and stable production of biogas. During biogas formation, the uptake of micronutrient metals by microorganisms is controlled by a complex network of biological and chemical reactions, in which reduced sulfur (S) compounds play a central role. LÄS MER