Sökning: "reproductive effort"

Visar resultat 31 - 35 av 36 avhandlingar innehållade orden reproductive effort.

1. 31. Age-specific trade-offs in life-history evolution

   Författare :Martyna K. Zwoinska; Alexei Maklakov; Marjo Saastamoinen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; life history; trade-off; learning; aging; sex differences; dispersal; Caenorhabditis; Drosophila; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology;

   Sammanfattning : Trade-offs prevent selection from driving all fitness-enhancing traits towards values that would maximize fitness. Life-history trade-offs, such as the one between survival and reproduction are well-studied, yet trade-offs can also involve behavioural or cognitive traits. LÄS MER

3. 32. Fish population responses to climate change : Causes and consequences

   Författare :Matilda L. Andersson; Peter Eklöv; Brian Hayden; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; browning; climate change; DOC; intraspecific variation; metabolism; resource use; warming;

   Sammanfattning : Lake environments are heterogeneous, and animals show a variety of adaptations to deal with this heterogeneity. Fish often show intraspecific variation in diet, metabolism, and behavior, corresponding to their habitat use. LÄS MER

4. 33. 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

5. 34. Predator-induced phenotypic plasticity in the marine mussel Mytilus edulis

   Författare :Olof Reimer; Christer Brönmark; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Systems Ecology; systemekologi;

   Sammanfattning : In this thesis I investigated whether the risk of predation can induce development of defensive traits in the blue mussel Mytilus edulis, a common species of the temperate seashores. I performed a series of field and laboratory experiments in which I exposed blue mussels to waterborne scents from its main predators, the starfish Asterias rubens, and the shore crab Carcinus maenas. LÄS MER

7. 35. The dose-dependent effects of estrogens on ischemic stroke

   Författare :Jakob Ström; Annette Theodorsson; Elvar Theodorsson; Mats Hammar; Torbjörn Bäckström; Linköpings universitet; []
   Nyckelord :;

   Sammanfattning : Estrogens are a group of female sex hormones that in addition to central roles in reproductive functions also have profound impact on for example brain development, blood vessels, bone tissue, metabolism and the immune system. The dominant endogenous production sites for estrogens in females are the ovaries and adipose tissue, while exogenous sources include combined contraceptive hormone treatments and menopausal hormone therapy. LÄS MER