Orchids offer excellent systems to study the role of ecology as a driver of morphological diversification since they exhibit intricate relationships with their pollinators that clearly affect the evolution of their floral morphologies. One such system is the orchid genus Catasetum (view the Orchid Gallery), which exhibits extreme floral sexual dimorphism as well as great diversity in male flower morphology and coloration between species. Thus, for my doctoral dissertation I am studying the floral evolution and complex pollination ecology of Catasetum, which is strictly pollinated by male euglossine bees. The evolution of floral sexual dimorphism and male flower
diversity in Catasetum is hypothesized to have been driven by male flower competition for pollinators, apparently achieved by eliciting pollinator aversion to male flowers through the high speed emplacement of the unusually heavy Catasetum pollinarium (the pollen-bearing structure of some monandrous orchids, see figure below, right). I am characterizing the euglossine-Catasetum interaction from a variety of perspectives: studying the biomechanics of high-speed pollinarium emplacement; reconstructing the Catasetum phylogeny, and using comparative biomechanical and morphometric data
Curriculum vitae (pdf)
within this phylogenetic framework to test the above hypothesis of Catasetum floral evolution; conducting field studies to assess the aversion response (or lack thereof) of euglossine bees to male flowers of different Catasetum species; and modeling the euglossine-Catasetum interaction in order to gain insight into the origin of this complex pollination syndrome and its resulting diversity of floral forms.
Catasetum osculatum male flowers and dissected floral organs. Pollinaria in the lower right corner
