Our research focuses on the origin, evolution and regulation of sexual systems diversity and on the molecular and evolutionary mechanisms that underlie the complex developmental patterns and reproductive features in the brown algae. The brown algae are a eukaryotic supergroup that has been evolving independently of animals and land plants for more than a billion years. During that time, they acquired multicellularity and have become the third most developmentally complex lineage on the planet, rivalling land plants in terms of body size and complexity. In addition, brown algae exhibit a fascinating range of types of sexual life cycles and sex determination systems. The developmental and reproductive biology of animals and land plants has been studied for decades, but, surprisingly, the brown algae have been almost completely ignored and very little is known about how they function at the molecular level. Exploration of this extraordinary group of eukaryotes is expected to provide important, fundamental insights into the processes underlying the evolution of complex multicellular life.