E&E PhD Exit Seminar: My chemical romance: curious cases of speciation in sexually deceptive Australian orchids
Sexual deception is the most beguiling of pollination strategies to evolve. Deceitful plants mimic the sex-pheromones of insects, thereby luring them into visiting, mating with, and inadvertently pollinating their flowers! I will examine two fascinating cases of speciation in sexually deceptive orchids.
Orchid fanatics have been puzzled by Cryptostylis orchids for almost 100 years - how can four co-occurring orchid species that share a pollinator not hybridise? I address this conundrum by conducting a cross-pollination experiment and by testing several barriers to hybridisation such as geographic distribution, flowering time, pollinator behaviour, and ploidy level. I also delve into Asiatic jungles and taxonomic trauma looking for species not seen since their original description to generate the first phylogeny for the genus.
Due to the major role of floral chemistry in sexual deception, speciation can occur without morphological change, creating cryptic taxa. Such instances of speciation in action give us fascinating insights into plant speciation processes, and also raise conservation concerns for the treatment of cryptic taxa. I examine pollinator and chemical evidence for cryptic ecotypes within the enigmatic Warty Hammer Orchid complex, and apply species distribution modelling and novel chemical approaches to inform conservation management.