Sökning: "Karl Gotthard"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden Karl Gotthard.

1. 1. Life history analysis of growth strategies in temperate butterflies

   Författare :Karl Gotthard; David Sloan Wilson; Stockholms universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; zoologisk ekologi; Animal Ecology;

   Sammanfattning : .... 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 :NATURAL SCIENCES; NATURVETENSKAP; 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. Body Size Evolution in Butterflies

   Författare :David Berger; Karl Gotthard; Wolf Blanckenhorn; Stockholms universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Body size evolution; age- and size at maturity; life history theory; fecundity; predation risk; juvenile growth rate; Lepidoptera; Biology; Biologi; zoologisk ekologi; Animal Ecology;

   Sammanfattning : Life history research deals with the scheme of resource partitioning to a wide spectra of processes and the trade-offs shaping these events. One of the most fundamental life history trade-offs is the one of at which age- and size an organism should start to reproduce; reaching a large size at maturity is often advantageous in terms of high adult survival and reproductive potential, while to attain a larger size the organisms must prolong juvenile development which is assumed costly in terms of mortality. LÄS MER

5. 4. Evolution in changing environments revealed by fire melanism in pygmy grasshopper

   Författare :Magnus Karlsson; Anders Forsman; Karl Gotthard; Linnéuniversitetet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Evolution Melanism Polymorphism Pygmy grasshoppers; Biology; Biologi; Evolutionary Biology; Evolutionsbiologi;

   Sammanfattning : According to theory, genetic diversity can be maintained by environmental variation and the degree of genetic and phenotypic polymorphism may enhance the ability of populations to endure stress imposed by changing environments. In my thesis I used colour polymorphic pygmy grasshoppers (Tetrix subulata) as a model system to explore how environmental variation influenced genetic diversity. LÄS MER

7. 5. Geographic variation in life cycles : Local adaptation and ecological genetics in a temperate butterfly

   Författare :Olle Lindestad; Karl Gotthard; Sören Nylin; Christopher W Wheat; Greg Ragland; Stockholms universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; voltinism; local adaptation; insect; life cycle; seasonality; genomics; life history; zoologisk ekologi; Animal Ecology;

   Sammanfattning : Conditions in nature change with the seasons, necessitating seasonal adaptations that synchronize the life cycles of organisms with their surroundings. Such regulatory adaptations must vary between populations to track local variation in climate and seasonality; this local adaptation is facilitated by locally specific seasonal cues, but may be hampered by gene flow and genetic history. LÄS MER