Professor Hanna Kokko, a Laureate Fellow at the Australian National University, has made a sustained and brilliant contribution to the disciplines of ecology and evolutionary biology. Although her contribution is dominated by her development of novel mathematical theory to probe key conceptual issues, her work is distinguished by her ability to apply clear thinking to questions deeply rooted in biology and natural history, and her astonishing degree of engagement with empiricists. Her numerous awards include election to the Finnish Academy of Science and Letters, and the Per Brinck Oikos Award for extraordinary and important contributions to the science of ecology.