Sökning: "evolutionär genetik"

Visar resultat 11 - 15 av 66 avhandlingar innehållade orden evolutionär genetik.

1. 11. The evolution of sex chromosomes and sex-linked sequences in birds

   Författare :Homa Papoli Yazdi; Hans Professor; Bengt Hansson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; sex chromosomes; female heterogamety; recombination suppression; genetic map; inversions; genetic diversity; pseudoautosomal region; Biology with specialization in Evolutionary Genetics; Biologi med inriktning mot evolutionär genetik;

   Sammanfattning : Identifying the processes involved in the evolution of suppressed recombination between sex chromosomes and understanding their consequences for the evolutionary dynamics of sex-linked loci have been major topics of research during the last century. In this thesis, I used the avian ZW system, where females are the heterogametic sex, to investigate the underlying processes in sex chromosome evolution in birds. LÄS MER

3. 12. 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

4. 13. Splitting the sexes : The birth and senescence of sex chromosomes

   Författare :Aivars Cirulis; Evolutionär ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sex chromosome; Sexual conflict; Macrostomum lignano; Experimental evolution; Genomics of sex;

   Sammanfattning : The evolution of gonochorism from hermaphroditism can be gradual by increasing investment in one sex role while decreasing in the other, or rapid through the fixation of sex-role sterility mutations, eventually leading to the evolution of sex chromosomes. It is expected that the transition will involve a temporary state of gynodioecy or androdioecy as the mutations are not expected to take place at the same time. LÄS MER

5. 14. The genomic basis of the response to female-limited X-chromosome evolution

   Författare :Yesbol Manat; Evolutionär ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; X chromosome; Sex chromosome; Drosophila melanogaster; Experimental evolution; sexual selection; intralocus sexual conflict;

   Sammanfattning : In this thesis, I attempted to achieve a better understanding of the nature of X-linked polymorphic loci using a female-limited X chromosome (FLX) experimental evolution in Drosophila melanogaster. I expected that expressing the evolved X chromosome will result in an increase in female fitness and a decrease in male fitness. LÄS MER

7. 15. Sex Chromosome Evolution in a Hermaphrodite : Genetic and phenotypic relationships between sex roles

   Författare :Anna Nordén; Evolutionär ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Sex chromosome evolution; Hermaphrodite; Inter-sexual genetic correlation; Quantitative genetics; Macrostomum lignano; Experimental evolution; Sexual conflict;

   Sammanfattning : Sex chromosome evolution in a hermaphrodite ancestor starts with the establishment of a sex-determining region (SDR). Over time, sex-specific genes, and/or sexually antagonistic alleles will become linked to the SDR. LÄS MER