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Visar resultat 21 - 25 av 36 avhandlingar som matchar ovanstående sökkriterier.

1. 21. Environmental heterogeneity, population dynamics and life-history differentiation in Primula farinosa

   Författare :Tove von Euler; Johan Ehrlén; Jon Ågren; Olav Skarpaas; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Plant Ecology; växtekologi;

   Sammanfattning : Allocation to reproduction is a key life-history trait. Optimal allocation to reproduction depends on environmental conditions because of their effects both on costs and benefits of reproduction and on patterns of growth, fecundity, and mortality. LÄS MER

3. 22. Sex, Molecules, and Gene control : Ecophysiological and evolutionary aspects of key sponge species from Antarctic shallow waters and the deep sea

   Författare :Vasiliki Koutsouveli; Paco Cárdenas; Anders Backlund; Ana Riesgo; Cassandra G. Extavour; Uppsala universitet; []
   Nyckelord :Porifera; Demospongiae; Geodia spp.; Phakellia ventilabrum; reproduction; gametogenesis; Antarctica; deep sea; sponge grounds; histology; molecular machinery; electron microscopy; RNA-seq; proteomics; lipidomics; Farmakognosi; Pharmacognosy;

   Sammanfattning : Very little is known about the ecophysiological aspects of Porifera (sponges) from Antarctica and North Atlantic, even though they are keystone components of these habitats. Being the earliest diverging metazoan lineage, sponges also play a fundamental role in our understanding of animal evolution. LÄS MER

4. 23. Paternal care, filial cannibalism and sexual conflict in the sand goby, Pomatoschistus minutus

   Författare :Maria Lissåker; Charlotta Kvarnemo; Ulrika Candolin; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; female choice; filial cannibalism; Gobiidae; parental care; Pomatoschistus minutus; sand goby; sexual conflict; sexual selection; Biology; Biologi;

   Sammanfattning : Natural and sexual selection and sexual conflict are forces shaping the evolution of reproductive behaviour, while constrained by factors like environment, physiology and life-history trade-offs. Parental care is costly both in terms of time and energy. LÄS MER

5. 24. Population dynamics of a perennial herb (Plantago maritima L.) along a distributional gradient : a demographical study

   Författare :Lenn Jerling; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Populationsekologi; Grobladsväxter;

   Sammanfattning : In order to explain density distribution and provide the basis for further research on life history phenomena, the demography of Plantago maritima is described along a distributional gradient from mean water level to the epilitoral. The results seem to suggest that the factors affecting distribution are differences in 1. LÄS MER

7. 25. Physiological trade-offs in reproduction and condition dependence of a secondary sexual trait

   Författare :Måns S. Andersson; Victor Apanius; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Trade-offs; life history; immune ecology; cost of reproduction; costs of immune response; sexual selection; migration; moult; Newcastle disease; HbA1C; Ficedula albicollis; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; Animal Ecology; zooekologi;

   Sammanfattning : This thesis examines parental condition, how it is traded off against reproduction and how it is displayed in a secondary sexual trait. The studies were performed on nest-box breeding collared flycatchers Ficedula albicollis on the island of Gotland, in the Baltic Sea. LÄS MER