The aim of this project is to understand the evolution and genomic basis of female-limited colour polymorphisms, particularly in the genus Ischnura (forktails), but also across the entire superfamily of Pond Damselflies and their relatives (Coenagrionoidea). We use DNA- and RNA-sequencing data from several species, particularly the Common Bluetail Damselfly (Ischnura elegans), our main model organism for which we have access to long-term ecological field data since the year 2000 (25 years). This species has a female-limited genetic colour polymorphism that is maintained by negative frequency-dependent selection caused by male mating harassment. We focus on several questions related to this colour polymorphism, such as: 1/the genomic basis of the polymorphism, 2/consequences for gene expression, 3/links to thermal adaptation, 4/role in sexual antagonism 5/macroevolutionary dynamics and 6/the role of hybridization across species in explaining the phylogenetic distributions of colour polymorphisms. I am a full professor at the Department of Biology (Lund University) since 2008. I am a full professor at the Department of Biology (Lund University) since 2008, and my research on the genetics and population biology of I. elegans has been funded by the Swedish Research Council (VR) since the year 2000, when my long-term studies were initiated.