Rate My Professor John Pannell

John Pannell is Full Professor in the Department of Ecology and Evolution within the Faculty of Biology and Medicine at the University of Lausanne. He leads the Pannell Group, which investigates the ecology and evolution of plant sexual systems. Current projects examine transitions between sexual systems, including hermaphroditism, monoecy, and dioecy, and their implications for mating patterns, sex allocation, demography, sexual dimorphism, and the evolution of the genome and transcriptome, particularly sex chromosomes. The group integrates theoretical modeling, wet-lab experiments, bioinformatics analyses, and fieldwork, often using model systems such as the wind-pollinated herb Mercurialis annua. His research addresses why many formerly hermaphroditic plants evolve separate sexes and the ecological and genomic consequences of such transitions, including interactions with metapopulation dynamics and range expansions.

Pannell earned an Honours degree in Biology from the University of Sydney in 1990, followed by work in conservation ecology in Tasmania. He completed his PhD at the University of Oxford, focusing on the evolution of combined versus separate sexes in plants. He conducted postdoctoral research with Spencer Barrett at the University of Toronto and Brian Charlesworth at the University of Edinburgh before establishing his research group in 1999 at Oxford's Department of Plant Sciences. In 2011, he joined the University of Lausanne. Key publications include 'The costs of reproduction can and do differ between the sexes' (Annals of Botany, 2025), 'Sex-allocation trade-offs and their genetic architecture revealed by experimental evolution' (PNAS, 2026), 'Dioecy in a wind-pollinated herb explained by disruptive selection on sex allocation via inbreeding avoidance' (Evolution, 2025), 'The scope of Baker's law' (New Phytologist, 2015), and 'On the origins of Y and W chromosomes as an outcome of sex allocation evolution' (Evolution Letters, 2023). With thousands of citations, his contributions have advanced understanding of plant mating-system evolution and sex chromosome origins. He was elected President of the steering committee for Switzerland's National Research Programme 84 'Plant Breeding Innovation' in 2023.