Sökning: "evolution of sexual reproduction"

Visar resultat 1 - 5 av 38 avhandlingar innehållade orden evolution of sexual reproduction.

1. 1. Experimental Evolution of Life-history : Testing the Evolutionary Theories of Ageing

   Författare :Hwei-yen Chen; Alexei Maklakov; Tracey Chapman; Uppsala universitet; []
   Nyckelord :senescence; ageing; longevity; mortality; experimental evolution; Caenorhabditis remanei; Biologi; Biology;

   Sammanfattning : Ageing reduces fitness, but how ageing evolves is still unclear. Evolutionary theory of ageing hinges on the fundamental principal that the force of natural selection declines with age. LÄS MER

3. 2. Sexual Conflict and Gene Expression in Drosophila melanogaster

   Författare :Paolo Innocenti; Edward Morrow; Göran Arnqvist; Andrew G Clark; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sexual conflict; sexual selection; male-female coevolution; gene expression; transcriptome; microarrays; sexual dimorphism; Drosophila; Biology; Biologi; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology; Biology with specialization in Evolutionary Genetics; Biologi med inriktning mot evolutionär genetik;

   Sammanfattning : Sexual conflict is broadly defined as a conflict between the evolutionary interests of the two sexes. Depending on the genetic architecture of the traits involved, it can occur at the level of male-female interactions or take the form of selection acting to change the mean of a shared trait against the sign of its genetic correlation. LÄS MER

4. 3. The balance between sex and asex: evolutionary genetic studies of reproductive variation in Allium vineale

   Författare :Alf Ceplitis; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ontogeny; growth animal ; Allium vineale; Development biology; evolution; sexual reproduction; reproductive systems; embryology; Utvecklingsbiologi; ontogeni; embryologi; Genetics; cytogenetics; Genetik; cytogenetik;

   Sammanfattning : Evolutionary theory predicts a disadvantage to sexual reproduction. This manifests itself either by the higher growth rate of asexual females in a dioecious species, or by the higher transmission rate of a gene conferring asexual female function to its carriers in a hermaphrodite species. LÄS MER

5. 4. Polyandry and the evolution of reproductive divergence in insects

   Författare :Tina Nilsson; Göran Arnqvist; David Hosken; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Bruchidae; cryptic female choice; multiple mating; sexual conflict; sexually antagonistic coevolution; sexual selection; speciation; sperm competition; Tenebrionidae; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

   Sammanfattning : Multiple mating by females is common in nature. Yet, the evolution and maintenance of polyandry remains a bit of an evolutionary puzzle. It was my aim in this thesis to reach a greater understanding of this phenomenon as well as to investigate the consequences of polyandry on the evolution of reproductive divergence in insects. LÄS MER

7. 5. Sexual Selection and Adaptation to Novel Environments

   Författare :Ivain Martinossi-Allibert; David Berger; Göran Arnqvist; Lukas Schärer; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sexual selection; Environmental change; Sexual conflict; Environmental stress; Adaptation; Adaptive landscape; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology;

   Sammanfattning : The work included in this thesis aims at exploring the environmental sensitivity of benefits and costs of sexual selection through a combined empirical and theoretical effort, to increase our understanding of the impact of environmental change on sexually reproducing populations.Can sexual selection promote adaptation to novel environments? Sexual selection for good genes should accelerate adaptation by granting higher reproductive success to individuals of high genetic quality. LÄS MER