The evolution and ecology of heterospory

Heterospory (sex- and size-distinct spores) was one of the most innovative events in the evolutionary history of land plants, yet very little is known about the ecological advantage it gave to early plants.This thesis investigates the ecological advantage of heterospory and the ecological consequences of its evolution. The results suggest that heterospory is a mechanism to help young plants establish in complex environments, especially in low light. It also finds that sex allocation in the free-sporing Selaginella is extremely male-biased, while in flowering plants it is well established to be female-biased.