Format: ORAL

Amanda L. Grusz1,2 and Michael D. Windham3

1 Department of Biology, University of Minnesota Duluth, Duluth, USA 2 Department of Botany, Smithsonian Institution, Washington, USA 3 Department of Biology, Duke University, Durham, USA

Obligate apomixis -- asexual reproduction by seed, spore, or egg -- has evolved repeatedly across the tree of life, in diverse organisms ranging from animals (such as reptiles, insects, and fishes) to angiosperms and other plants. Despite its many origins, and the intriguing ecological and evolutionary parallels among them, little is known regarding the causes and long-term consequences of this heritable reproductive syndrome. Some studies suggest that drought, or periodic water limitation, could be key to driving the repeated evolution of obligate apomixis. To evaluate the drought hypothesis, we are uniting genomic, spatial, environmental, and life history data (across multiple evolutionary and ecological scales), leveraging ferns as a model system. Current estimates indicate that 1030% of ferns exhibit obligate apomixis, which has evolved repeatedly in xeric and monsoonal environments around the world. Dry environments impose major constraints on plant life histories and the fern life cycle is especially vulnerable. In this study, we focus on North American desert ferns, integrating reproductive traits (karyotype, gametophyte development, and spore size/number), climate and microhabitat, and phylogenomic data to specifically ask: Does environmental niche predict obligate apomixis or its constituent traits in desert ferns of North America? This work aims to further bridge generational gaps in technical expertise among next-generation researchers for a variety of cutting-edge and classical approaches, stimulating interdisciplinary student-driven research that emphasizes the value and relevance of museum specimens for addressing fundamental biological questions.