We use the reproductive structures of vascular plants to investigate the factors that generate and influence morphological diversity over long timescales. We often approach these questions by linking general functional demands, such as spore dispersal, the capture of pollen grains, the protection of maturing seeds, or the dispersal of mature seeds, with patterns of morphological diversity or change through time. For example, data from Paleozoic, Mesozoic, and modern conifers suggests that seed cones have become proportionally wider over time, with an important shift occurring in the Jurassic. This change is primarily driven by an increasing amount of cone scale tissue relative to seed tissue, suggesting that more recent conifers devote more tissue to surrounding and protecting seeds.
We have also explored on how broad morphological patterns in reproductive structures are shaped by variation in plant architecture and branching habits, which exert a strong influence on the size of reproductive structures and how they are arrayed on the parent plant.
Much of this work has been done in conifers, but projects have also focused on other groups of living and extinct gymnosperms, free-sporing plants such as lycopsids, and a range of lineages in the Devonian.
Bonacorsi, N.K. and Leslie, A.B. 2019. Sporangium position, branching architecture, and the evolution of reproductive morphology in Devonian plants. International Journal of Plant Sciences 180: 493-503.
Bonacorsi, N.K. and Leslie, A.B. 2019. Functional diversity and convergence in the evolution of plant reproductive structures. Annals of Botany 123: 145-152.
Leslie, A.B., Beaulieu, J.M., Mathews, S. 2017. Variation in seed size is structured by dispersal syndrome and cone morphology in conifers and other nonflowering seed plants. New Phytologist 216: 429-437.
Leslie, A.B., Beaulieu, J.M., Crane, P.R., and Donoghue, M.J. 2014. Cone size is related to branching architecture in conifers. New Phytologist 203: 1119-1127.
Leslie, A.B. 2011. Predation and protection in the macroevolutionary history of conifer cones. Proceedings of the Royal Society of London B 278: 3003-3008.