2-year postdoctoral position in "Population Genomics of Sex Chromosomes in Jaera" with Christelle Fraïsse. Start date: September 2026 (preferred but negotiable). Applications are welcome from now on until the position is filled. Location: Institute of Evolutionary Science of Montpellier, Montpellier University (France). https://isem-evolution.fr/en/ ISEM is a research institution focusing on biodiversity origins, dynamics and the associated evolutionary mechanisms and processes. It hosts a total of ca. 250 scientists spread across 4 research departments. Montpellier is a vibrant university city located in the South of France. Several stays in the Station Biologique of Roscoff, Sorbonne University (France). https://www.sb-roscoff.fr/en It is a marine biology and ecology laboratory with nearly 200 scientists working to study marine organisms and understand the functioning of complex and dynamic marine ecosystems. It is located in Roscoff, a maritime village on the north coast of Brittany in France. Salary: Monthly net salary is ca. 2,300 euros, according to experience. The contract includes health insurance and 44 days of annual leave. Context: ANR project "SexIsol" (2023-2028) led by Thomas Broquet. Evolution of sexual isolation in the species complex of Jaera albifrons crustaceans. This project aims to test hypotheses about two complementary questions using an empirical study of the Jaera albifrons complex. How might sexual isolation have evolved? What exactly is the role of chromosomal rearrangements and sex chromosomes (ZW system), which have been pointed to in the development of sexual isolation? Project: With that global aim, the post-doctoral candidate will first characterize, at the molecular level, the sex chromosomes across multiple species within the complex, including the degree of differentiation between the Z and W chromosomes, the extent of degeneration, chromosomal rearrangements, and patterns of dosage compensation. It will then reconstruct their evolutionary dynamics across the Jaera albifrons’ species complex. Next, the role of sex chromosomes as reproductive barriers to introgressive hybridization will be assessed through genome-wide scans and model-based inference. Gene expression data will also be analyzed to quantify sexual dimorphism in expression, interspecific expression divergence, and hybrid misregulation. Profile: The candidate must hold a doctoral degree and have a strong background in population genetic and evolution. The ideal candidate should be motivated, have good communication skills, and be willing to work independently and collaboratively, integrating effectively into this collaborative project through active engagement with doctoral researchers and bioinformatics engineers. Prior experience in any of the following areas will be an advantage: i) population genomics (short-reads and long-reads). ii) transcriptomics (short-reads). iii) programming skills (e.g. R, Python, bash, C). iv) experience with high-performance computing (e.g. slurm). How to apply: i) motivation letter describing research interests, relevant experience and interest in the position (max. two pages). ii) CV, including a list of publications. iii) copies of academic diplomas. iv) names and email addresses of at least two references. All applications must be sent to Christelle Fraïsse (christelle.fraisse@umontpellier.fr) and Thomas Broquet (thomas.broquet@sb-roscoff.fr) by email. Christelle Fraisse (to subscribe/unsubscribe the EvolDir send mail to golding@mcmaster.ca)