Keywords: adaptation, phenology, natural selection, quantitative genetics, male fitness
My research draws on molecular lab techniques, glasshouse and garden manipulations, computer simulation, and good old careful field observation to better understand the causes and consequences of plant diversity.
Ideas I am pursuing include:
Functional significance of pollen variability
The pollen grain was a key innovation in the evolution of the land plants. This tiny package transports sperm within a safe envelope, freeing the seed plants from the short mating distances typical of their cousins. Given this critical role, we expect selection to act strongly on pollen characters, and can’t help but be intrigued by species in which pollen grains vary from plant to plant. I am spending the springs of my postdoctoral research in the Forrest lab investigating pollen colour polymorphism in genus Erythronium. I am coordinating a citizen science effort to document where the morphs occur, and performing experiments aimed at understanding why they occur. The poster I presented on this work at Evolution 2016 was featured on the Better Posters Blog; you can also see it here.
The complex fitness effects of flowering time
Flowering time almost certainly affects plant fitness, but the causal mechanisms linking phenology to seed production and seed siring are obscured by the inherent correlation between an individual’s size at flowering (a function of age at flowering) and its exposure to pollinators, frugivores, and abiotic stresses (functions of Julian date of flowering). The cornerstone of my dissertation research with Art Weis was a manipulative garden experiment in which I staggered the planting dates of families of Brassica rapa to isolate these correlated effects. I estimated selection through male and female fitness components, finding that female fitness benefited from an early flowering date, while age at flowering mattered more to male fitness. Ongoing work seeks to determine why old plants make crummy dads. I chatted about this research on the In Defense of Plants podcast in April 2016.
Consequences of within-plant variation
Variation among the repeated structures on a plant (e.g. flowers, leaves, fruit) has been considered a hindrance to the study of plant traits, but could this within-plant variation also be of ecological and evolutionary importance? During my dissertation, I developed a model demonstrating that decreasing fruit set probability from first to last flowers on plants (a frequently observed pattern) can generate selection for early flowering onset. This work sparked my interest in the social world of plants – that is, how does the phenotype of one individual affect the fitness of another?