We explore patterns in the evolution of reproductive morphology at the broadest scales by analyzing complexity across vascular plant reproductive structures. We quantify complexity by recording the number and arrangement of the component parts of reproductive structures, as well as characterizing physical or functional interactions among them. These approaches allow us to directly compare disparate reproductive structures across lineages of early plants and extinct and extant pteridophytes, gymnosperms, and angiosperms. This work suggests that functional diversity plays a large role in the evolution of plant complexity; reproductive structures that perform more diverse, or more specialized, functions consistently have more parts. In addition, specific evolutionary innovations within lineages, particularly those relating to pollination, are associated with large increases in complexity.
Leslie, A. B., Simpson, C., Mander, L. 2021. Reproductive innovations and pulsed rise in plant complexity. Science 373: 1368-1372.