This PhD position at Naturalis Biodiversity Center in Leiden, the Netherlands, offers a unique opportunity to contribute to global biodiversity research by investigating the dating and tracing of human-mediated plant introductions in the Pacific Islands. The successful candidate will join the Marie Curie Doctoral Network project, PacificPeopleForest, which explores the history, archaeology, and botany of Pacific Islands, focusing on the long-term impacts of early European colonialism on people and forests. The project addresses the often-overlooked fact that many native forests in the Mariana Islands consist of introduced species, and aims to trace how plant use and forest composition changed with European contact and the influx of non-native species. The PhD student will use genomics methods to trace and date key forest species, supporting both historical and archaeological research. Additionally, the candidate will initiate the first pilot study on isotope dendrochronology for the Marianas Islands, conduct fieldwork on Rota Island, collaborate with European partners, publish findings in peer-reviewed journals, and present results at national and international conferences. The position offers a gross monthly starting salary of €3,463.00 (full-time, 36 hours), with additional benefits including an end-of-year bonus, holiday pay, generous leave, commuting allowance, pension scheme, laptop and mobile phone allowance, and access to professional development opportunities. The research environment at Naturalis is state-of-the-art, with extensive lab facilities and one of the world’s largest natural history collections. The PhD student will be supervised by Dr. Frederic Lens, Dr. Marta Domínguez Delmás, and Dr. Angelica Cibrian Jaramillo, and will work closely with an international team of researchers and other PhD students in the PacificPeopleForest consortium. The ideal candidate will have a completed Master’s degree in a relevant field, experience with molecular data and bioinformatics, and preferably experience with tropical fieldwork and knowledge of plant biogeography and evolution. Strong organizational skills, willingness to participate in international workshops and training, and proficiency in English are required. The application deadline is November 23rd, 2025, with interviews expected to be held online on November 27-28, 2025. Applicants should submit a CV and motivation letter, including contact details of two referees, as a single PDF via the application link. The position offers a vibrant academic and social community, with opportunities for professional growth and meaningful contributions to biodiversity science.