Research Interests

Polyploidy

Whole genome duplication is common across many forms of life, especially plants. The formation of polyploid plants through WGD is implicated in at least 15% of angiosperm speciation events (and 30% in ferns) and is thought to occur at the base of the entire flowering plant lineage. The prevalence of polyploid speciation events around periods of dramatic climatic changes have led to the hypothesis that polyploids are uniquely capable of rapidly adapting to new environments. However, most evidence for physiological and ecolgoical differences between polyploids and diploids originates from observational studies of natural autopolyploids, which have undergone countless generations of natural selection, and mostly ignores allopolyploids due to their often uncertain parentage. Thus, the actual contribution of polyploidy to novel ecological traits seperate from other processes, including natural selection and hybridization, remains unclear.

Fern gametophyte physiology

Range-wide variation in traits related to climatic adaptation is commonly observed in flowering plants, but little is known about ferns in this context. Ferns also have an independent gametophyte stage, which is physiologically distinct from a sporophyte. As a result, the ecophysiology of the fern gametophyte is highly consequnetial for the overall success of a fern species. If only one life stage can withstand current environmental conditions, than the species may not persist in that area.

Polystichum munitum is a widespread and important fern species on the North Pacific Coast, frequently growing in Redwood forests. Previous research has shown that the sporophytes derive a large proportion of their water from fog, as do many plants in this ecosystem. However, fog is less prevalent in the Southern reaches of the range, in addition to greater temperatures and less precipitation overall. Thus, we are presented with a natural ecogeographic gradient to test if gametophytes originating from populations across environments vary in their adaptation. By combining several experimental approaches, we are working to understand the capacity for variation in environmental tolerances within a single species.

Reproductive biology of ferns

Fern gametophytes typically posess both male and female sex organs, leading to the suggestion that ferns are habitual inbreeders which avoid the consequneces of self-fertilization through polyploidy. However, population genetic data and studies of gametophytes in lab and field settings routinely indicate that ferns are mostly outcrossing. Outcrossing is supported by