Research

Research interests


My reseach interest are within the field of evolutionary biology. In specific, I investigate how natural selection may result in evolutonary changes in wild populations of long-lived organisms.



PhD thesis (2010-2016)


In my PhD project I investigated how natural selection modify quantitative characters and result in evolutonary changes in wild populations of two different species, the house sparrow Passer domesticus and the moose Alces alces. Together with my collaborators Steinar Engen and Bernt-Erik Sather we developed novel methods to estimate selection in populations of long-lived organisms and provided a R-package (called "lmf") which implement these methods to empirical data. The title of my PhD thesis is Evolution by natural selection in age-structured populations in fluctuating environments.



MSc thesis (2008-2010)


In my MSc project I investigated patterns of propagule size together with my coauthors Henrik Jensen, Thor H. Ringsby and Bernt Erik Saether. Propagule size represents an important life-history trait under maternal control. Despite a positive relationship between propagule size and components of fitness, propagule size displays tremendous amounts of variation within natural populations which causes are poorly understood. With a study of a house sparrows Passer domesticus we investigate maternal and environmental correlates of egg size, quantify variation in egg size within and between females and broods, and estimate heritability. The title of my Msc thesis is Correlates of egg size variation in a population of house sparrow Passer domesticus.



The house sparrow project


House sparrows have been captured and observed annually during the study period, from 1992 to present, on 18 islands covering an area of more than 1600 km2 off the coast of Helgeland in northern Norway. The islands are generally sparsely populated by humans. The islands can be divided into two major types, which are correlated to their distance from the mainland. At the eight inner islands the sparrows are living in close association with human settlements at and around dairy farms. On the remaining eleven outer islands the sparrows are foraging outdoor, and nest around peoples' houses with no proximity to farms. Because of the extensive capture and ringing protocol of fledglings, fledged juveniles and adults, more than 90 % of all adult birds were individually marked during the study period. Recaptures and observations of marked adult birds will be used to determine whether fledglings and juveniles survived until recruitment the following breeding season. For the populations on the inner islands complete pedigrees have been made, however this remains to be done in all years for populations on the outer islands. Parentage was and will be determined by genetic analyses of DNA extracted from blood by standard methods. Up to 15 highly polymorphic microsatellite loci are used in the genotyping procedure.

The moose project


Moose have been captured and banded annually during the study period, from 1992 to present, on the island of Vega (65°40'N, 11°55'E) in northern Norway. This populations was founded in 1985 and due to observations and annual hunting records the population size is also well known from 1985 to the start of the study. Vega is 119 km2, is dominated agricultural land, marches and sparsely populated deciduous forests, and has a mild climate with little snow during winter. During the study period, a very large proportion of the animals on the island have been banded, measured for morphological traits and DNA sampled. At present genetic pedigrees are beeing constructed based on microsatellite loci.