Severine Kotrschal


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Telefon 08-16 40 54
Besöksadress Svante Arrheniusväg 18 B
Rum D550b
Postadress Zoologiska institutionen: Etologi 106 91 Stockholm



Séverine Denise Buechel


I am interested in the ultimate causes for social evolution and in the mechanisms and rules of social interactions between animals in general. I worked on ants and bumblebees aiming to understand the benefits and drawbacks of group living under parasite pressure and I studied Lake Tanganyika cichlids in their natural habitat to gain insights in the social structure and their motivation to live and engage in groups of unrelated individuals.

I am a researcher in a multidisciplinary Wallenberg project (PI: Niclas Kolm) in which we are using an artificial selection approach to investigate the basis of vertebrate sociality. This complements previous and ongoing research on brain evolution in guppies artificially selected for relative brain size in which I have been involved in at the Veterinary University in Vienna, Austria.

fish (427 Kb)


I urval från Stockholms universitets publikationsdatabas
  • 2017. Alison E. Wright (et al.). Nature Communications 8

    Sex chromosomes evolve once recombination is halted between a homologous pair of chromosomes. The dominant model of sex chromosome evolution posits that recombination is suppressed between emerging X and Y chromosomes in order to resolve sexual conflict. Here we test this model using whole genome and transcriptome resequencing data in the guppy, a model for sexual selection with many Y-linked colour traits. We show that although the nascent Y chromosome encompasses nearly half of the linkage group, there has been no perceptible degradation of Y chromosome gene content or activity. Using replicate wild populations with differing levels of sexually antagonistic selection for colour, we also show that sexual selection leads to greater expansion of the non-recombining region and increased Y chromosome divergence. These results provide empirical support for longstanding models of sex chromosome catalysis, and suggest an important role for sexual selection and sexual conflict in genome evolution.

  • 2017. A. Hayward (et al.). Journal of Evolutionary Biology 30 (6), 1056-1067

    Parasite diversity and abundance (parasite load) vary greatly among host species. However, the influence of host traits on variation in parasitism remains poorly understood. Comparative studies of parasite load have largely examined measures of parasite species richness and are predominantly based on records obtained from published data. Consequently, little is known about the relationships between host traits and other aspects of parasite load, such as parasite abundance, prevalence and aggregation. Meanwhile, understanding of parasite species richness may be clouded by limitations associated with data collation from multiple independent sources. We conducted a field study of Lake Tanganyika cichlid fishes and their helminth parasites. Using a Bayesian phylogenetic comparative framework, we tested evolutionary associations between five key host traits (body size, gut length, diet breadth, habitat complexity and number of sympatric hosts) predicted to influence parasitism, together with multiple measures of parasite load. We find that the number of host species that a particular host may encounter due to its habitat preferences emerges as a factor of general importance for parasite diversity, abundance and prevalence, but not parasite aggregation. In contrast, body size and gut size are positively related to aspects of parasite load within, but not between species. The influence of host phylogeny varies considerably among measures of parasite load, with the greatest influence exerted on parasite diversity. These results reveal that both host morphology and biotic interactions are key determinants of host-parasite associations and that consideration of multiple aspects of parasite load is required to fully understand patterns in parasitism.

  • 2017. Alberto Corral-López (et al.). Science Advances 3 (3)

    Mate choice decisions are central in sexual selection theory aimed to understand how sexual traits evolve and their role in evolutionary diversification. We test the hypothesis that brain size and cognitive ability are important for accurate assessment of partner quality and that variation in brain size and cognitive ability underlies variation in mate choice. We compared sexual preference in guppy female lines selected for divergence in relative brain size, which we have previously shown to have substantial differences in cognitive ability. In a dichotomous choice test, large-brained and wild-type females showed strong preference for males with color traits that predict attractiveness in this species. In contrast, small-brained females showed no preference for males with these traits. In-depth analysis of optomotor response to color cues and gene expression of key opsins in the eye revealed that the observed differences were not due to differences in visual perception of color, indicating that differences in the ability to process indicators of attractiveness are responsible. We thus provide the first experimental support that individual variation in brain size affects mate choice decisions and conclude that differences in cognitive ability may be an important underlying mechanism behind variation in female mate choice.

Visa alla publikationer av Severine Kotrschal vid Stockholms universitet

Senast uppdaterad: 21 april 2019

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