CAREER: Polyploid phylogenetics and ploidy-aware taxonomy of Cystopteridaceae: Research and education from the field to museum collections

Utah State University, Logan UT

Investigators

Abstract

Polyploid species—species with more than the two complete sets of chromosomes—are common across the tree of life, especially in plants. These polyploids are often also hybrids, with their different chromosome sets coming from different parent species. Such “allopolyploids” are a tremendously important component of global biodiversity, but study of their long-term evolution (the field of phylogenetics) has been limited because allopolyploids have a web-like rather than tree-like evolutionary history and thus standard tools for phylogenetic analysis do not apply. This research will develop phylogenetic tools for the study of allopolyploids and demonstrate the effectiveness of these tools for understanding complex patterns of biodiversity and the processes that generated them in the widespread fern family, Cystopteridaceae. In conjunction with this research, the project will leverage the power of field- and collections-based experiences to provide transformative educational opportunities for an annual cohort of students transferring to Utah State University (USU) Logan, including the creation of an associated Blanding Four Corners Herbarium. Opportunities for mentored research experiences for undergraduate and graduate students will be integrated with the project’s research activities, and an Intermountain Herbarium Foray Program will be offered, which will generate important biodiversity data and provide field botany experiences to the public while connecting them with the local environment. This project will develop a phylogenetic tree model that incorporates the processes of lineage birth, death, and polyploidization, which will allow for the biologically-informed inference of the reticulate evolutionary history of polyploids and testing of hypotheses related to polyploid diversification. A densely sampled polyploid species network for the fern family Cystopteridaceae will be inferred from a multi-locus dataset of approximately 1500 accessions, which will provide the first major, focused empirical test of the “dead-end” hypothesis of polyploid macroevolution. Finally, an online revisionary monograph showcasing “ploidy-aware” revisionary systematics and the potential of dynamic online e-monography will provide a critical resource for members of the broader public. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.