Sökning: "gradual evolution"

Visar resultat 21 - 25 av 55 avhandlingar innehållade orden gradual evolution.

  1. 21. Adaptive Evolution and Demographic History of Norway Spruce (Picea Abies)

    Författare :Thomas Källman; Peter Tiffin; Uppsala universitet; []
    Nyckelord :;

    Sammanfattning : One of the major challenges in evolutionary biology is to determine the genetic basis of adaptive variation. In Norway spruce (Picea abies) the timing of bud set shows a very strong latitudinal cline despite a very low genetic differentiation between populations. LÄS MER

  3. 22. Bioinformatic Analysis of Mutation and Selection in the Vertebrate Non-coding Genome

    Författare :Mikael Brandström; Hans Ellegren; Diethard Tautz; Uppsala universitet; []
    Nyckelord :Biology; non-coding genome; selection; mutation; chicken; human; indel; microsatellite; sequence alignment; comparative genomics; bioinformatics; vertebrate; Biologi;

    Sammanfattning : The majority of the vertebrate genome sequence is not coding for proteins. In recent years, the evolution of this noncoding fraction of the genome has gained interest. These studies have been greatly facilitated by the availability of full genome sequences. LÄS MER

  4. 23. Evolutionsteorin i klassrummet : på väg mot en ämnesdidaktisk teori för undervisning i biologisk evolution

    Författare :Anita Wallin; Göteborgs universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES;

    Sammanfattning : The overall purpose of this thesis is to study how upper secondary school students (grade 10-12) develop an understanding of evolutionary biology as a result of teaching. Taking students’ preconceptions as the starting point a teaching sequence is designed with the aim that students shall learn the theory of evolution by natural selection in such a way that it becomes an intellectual tool. LÄS MER

  5. 24. Evolution of mate signalling in moths: Biosynthetic gene families and diversification of female sex pheromones

    Författare :Marjorie Liénard; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; duplication; transcriptome; fatty-acyl-CoA reductase; fatty-acyl-CoA desaturase; fatty-acid biosynthesis; odour; insect; Lepidoptera; phylogeny; qPCR; heterologous expression; mutagenesis;

    Sammanfattning : Pheromones are intraspecific chemical signals serving as a ubiquitous form of communication, particularly among insects. Female sex-pheromone signals act as the core constituent in the specialized odour-mediated moth mate-recognition system. Female moths typically release multicomponent mixtures of alcohols, aldehydes or acetates. LÄS MER

  7. 25. A mechanistic description of the evolution of aromatic tar during catalytic upgrading of the raw gas produced from biomass steam gasification

    Författare :Huong Nguyen; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; biomass gasification; raw gas; catalytic raw gas upgrading; ilmenite; kinetic model; tar;

    Sammanfattning : The removal of tar from the raw gas produced during biomass gasification is a prerequisite for the viability of the process downstream of the gasifier. The tar, the composition of which is dominated by aromatics, readily condenses, leading to process disruption. LÄS MER