Karin Norén

Karin Norén


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Arbetar vid Zoologiska institutionen
Telefon 08-16 40 34
Besöksadress Svante Arrhenius väg 18b
Rum D 515
Postadress Zoologiska institutionen: Ekologi 106 91 Stockholm

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I urval från Stockholms universitets publikationsdatabas
  • 2018. Malin Hasselgren (et al.). Proceedings of the Royal Society of London. Biological Sciences 285 (1875)

    Isolation of small populations can reduce fitness through inbreeding depression and impede population growth. Outcrossing with only a few unrelated individuals can increase demographic and genetic viability substantially, but few studies have documented such genetic rescue in natural mammal populations. We investigate the effects of immigration in a subpopulation of the endangered Scandinavian arctic fox (Vulpes lagopus), founded by six individuals and isolated for 9 years at an extremely small population size. Based on a long-term pedigree (105 litters, 543 individuals) combined with individual fitness traits, we found evidence for genetic rescue. Natural immigration and gene flow of three outbred males in 2010 resulted in a reduction in population average inbreeding coefficient (f), from 0.14 to 0.08 within 5 years. Genetic rescue was further supported by 1.9 times higher juvenile survival and 1.3 times higher breeding success in immigrant first-generation offspring compared with inbred offspring. Five years after immigration, the population had more than doubled in size and allelic richness increased by 41%. This is one of few studies that has documented genetic rescue in a natural mammal population suffering from inbreeding depression and contributes to a growing body of data demonstrating the vital connection between genetics and individual fitness.

  • 2018. Christer Wiklund (et al.). Biological Journal of the Linnean Society 123 (1), 179-190

    The majority of herbivorous insects are specialized in host use. Even among insects that use many hosts, local specialization is common with a single host plant often being used in any given locality. Here, we establish such a pattern for the European swallowtail butterfly, Papilio machaon. We sampled larvae on five different natural hosts at eight sites in Sweden, each locality showing local monophagy. We ask what is the underlying reason for this pattern, (1) local genetic adaptation with each population being genetically adapted to the local host, (2) Hopkins' host selection principle with adult females retaining a memory of the larval host and preferring to oviposit on that plant, or (3) the preference/performance hypothesis which posits that females should oviposit on the local plant(s) on which larval fitness is highest. Allozyme analysis supported a relatively low level of population structuring, and oviposition preference tests showed that females from all sites had similar preference rankings of the five host plants. Hence, there was no support for local genetic adaptation or Hopkins' host selection principle. Instead, the results are consistent with the preference/performance hypothesis with local monophagy probably being implemented by a preference ranking of plants in accordance with larval performance.

  • 2018. Erika Godoy, Karin Norén, Anders Angerbjörn. Polar Biology 41 (5), 945-951

    Mating patterns are highly context-dependent and the outcome of selection pressures formed by ecological factors, inbreeding levels and access to available partners. In small and inbred populations, matings are limited by high kin encounter rates and access to mates. In this paper, we use background pedigree data to investigate mating patterns and inbreeding avoidance in an isolated and critically endangered Arctic fox (Vulpes lagopus) population. Empirical data showed avoidance of matings within natal family. Based on 35 documented matings, we only recorded two full-sibling matings and these occurred between individuals from different natal families. Matings between second-order relatives, however, occurred to the same extent as between unrelated individuals. To test how this influenced the population development of inbreeding (f), we simulated scenarios of random mating, exclusion of natal family and exclusion of individuals in already existing pair bonds. The observed development of inbreeding did not correspond the expected scenario of random mating (linear regression, r2 = 0.354, P = 0.20), but showed a comparable outcome as the simulated development of discriminating natal family (linear regression, r2 = 0.980, P < 0.001). We conclude that behavioural, pre-copulatory inbreeding avoidance strategies occur in this population and that exclusion of mating with natal family causes a slower increase in inbreeding levels compared to random mating. This study demonstrates how long-term monitoring, pedigree construction and simulations can generate information valuable for an in-depth understanding of both conservation genetics and behavioural ecology in threatened populations.

  • 2018. Johan Wallén (et al.). Biological Journal of the Linnean Society
Visa alla publikationer av Karin Norén vid Stockholms universitet

Senast uppdaterad: 29 oktober 2018

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