We are inviting applications for a fully funded PhD position at the Division of Molecular Biology, Ruðer Bo škoviæ Institute in Zagreb, Croatia. Our lab focuses on comparative evolutionary biology, with an emphasis on rapid adaptation in extreme environments, using cave-dwelling animals as model systems. Our research combines fieldwork, organismal biology, molecular techniques, and omics approaches to explore both the proximate mechanisms (genetic, developmental, and physiological) and the evolutionary drivers (selection, plasticity, constraint) of adaptation. The PhD project will investigate how phenotypic plasticity contributes to evolutionary adaptation during cave colonization, using the Mexican cavefish (Astyanax mexicanus) as a model system. It will test whether environmentally induced responses to darkness in ancestral surface fish can precede and facilitate the evolution of robust cave-adapted traits. Focusing on eye development and degeneration, the project will examine plastic and evolved changes across developmental and molecular levels to identify mechanisms underlying plasticity, maladaptation, and genetic assimilation. Ultimately, the project aims to bridge the gap between environmental change and the evolution of novel phenotypes. More information about the project can be found on our lab website (https://bilandzija.irb.hr/Projects-and-Funding) and previous publications: doi: 10.7554/eLife.51830 and doi: 10.24272/j.issn.2095-8137.2022.528. Position details: Duration: 5 years (funding secured), includes a 6-month probation period. Requirements: Master's degree in Biology or a related field Proficiency in English Strong interest in evolutionary biology Preferred qualifications: Experience with NGS analysis, statistics/R Wet lab skills (e.g. staining, imaging) What We Offer A collaborative, English-speaking research environment Access to the Institute's facilities, including a dedicated Astyanax mexicanus facility and animal caretaker Professional development opportunities, including in-house workshops No teaching obligations (optional teaching/supervision available) Funding opportunities for conferences, workshops, and research visits abroad Full details and application instructions: https://euraxess.ec.europa.eu/jobs/417390 Application deadline: 10 April 2026, 23:55 CET In your motivation letter please include: your research interests and career goals, previous research experience (if any), why you want to join our lab, and how you can contribute to our project. Feel free to contact Dr. Biland žija (hbilandz@irb.hr) for any questions. Helena Biland žija, PhD Principal Investigator Division of Molecular Biology Ruðer Bo škoviæ Institute Bijenicka cesta 54, P.O.Box 180 10000 Zagreb, Croatia https://bilandzija.irb.hr/ Helena Biland žija (to subscribe/unsubscribe the EvolDir send mail to golding@mcmaster.ca)