Sökning: "diapause"

Visar resultat 1 - 5 av 17 avhandlingar innehållade ordet diapause.

1. 1. Unraveling the regulatory mechanisms of pupal diapause termination

   Författare :Philip Süess; Philipp Lehmann; Christian Wegener; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Diapause; diapause termination; prothoracicotropic hormone; ecdysone; thermal performance; Functional Zoomorphology; funktionell zoomorfologi;

   Sammanfattning : Diapause is an essential part of many insect’s life cycle and is a developmental halt induced by environmental cues in advance of deteriorating conditions. Insects typically enter diapause to avoid unfavorable environmental conditions like low temperatures, poor food quality and the absence of conspecifics. LÄS MER

3. 2. The diapause switch : Evolution of alternative developmental pathways in a butterfly

   Författare :Inger Marie Aalberg Haugen; Karl Gotthard; Dan Hahn; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental plasticity; phenotypic plasticity; developmental switch; threshold trait; life-cycle regulation; direct development; Lepidoptera; zoologisk ekologi; Animal Ecology;

   Sammanfattning : Diapause decision is a classic example of a threshold switch mechanism with cascading effects on morphology, behaviour and life-history traits. This thesis addresses the downstream effects of the insect diapause switch, with the main focus on pathway-specific regulation of life-history traits, using the speckled wood butterfly (Pararge aegeria) as a study species. LÄS MER

4. 3. Functional genomics of diapause in two temperate butterflies

   Författare :Peter Pruisscher; Karl Gotthard; Dieter Ebert; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diapause induction; adaptation; genomics; transcriptomics; populationsgenetik; Population Genetics;

   Sammanfattning : Natural selection will act on a given phenotype to maximize fitness in a particular environment, even if this would result in reduced fitness in other environments. In insects some of the strongest selection pressures act on timing life cycles to seasonal variation in environmental conditions, in order to maximize growth, reproduction, and to anticipate the onset of winter. LÄS MER

5. 4. Life history evolution during a climate-driven butterfly range expansion

   Författare :Mats Ittonen; Karl Gotthard; Philipp Lehmann; Christopher Wheat; Sarah Diamond; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; climate change; diapause; genomics; insect cold tolerance; life cycle; local adaptation; parallel evolution; photoperiodism; reciprocal transplant; zoologisk ekologi; Animal Ecology;

   Sammanfattning : Climate change pushes species polewards and upwards – as temperatures rise, species move to areas that were previously too cold for them. During range expansions, species encounter unfamiliar environmental conditions, which may require evolutionary adaptation, but expanding populations may often be hampered by their genetic and demographic properties. LÄS MER

7. 5. Ecology of zooplankton communities: climate, dormancy, and benthic-pelagic coupling

   Författare :Mikael Gyllström; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Marinbiologi; limnologi; akvatisk ekologi; limnology; Hydrobiology; marine biology; aquatic ecology; phytoplankton; temporal stability; recruitment; seasonal succession; environmental cues; diapause; shallow lakes; predation; enrichment; climate; temperature;

   Sammanfattning : This thesis describes how influences, such as top down and bottom up forces, shape zooplankton communities in shallow lakes. I have also extended the traditional food-web theory by investigating the effects of climate on total biomass, taxonomic composition, and temporal properties of zooplankton communities. LÄS MER