Research
Evolution has generated an incredible diversity of plant form and physiological function that determine where plants can and cannot survive on the landscape, in which habitats, and next to which neighbors. Our research aims to explain how physiological function drives spatial distributions and ecological patterns of plant biodiversity and identify the eco-evolutionary mechanisms that generate plant physiological diversity. Our shared philosophy is that broad evolutionary and ecological patterns can be explained by connecting mechanisms across biological scales. To this end, we integrate the following questions that span anatomy, physiology, ecology, and evolutionary history:
1) how does anatomical structure promote & constrain function?
2) how are physiological traits & trade-offs coordinated?
3) how does physiology determine species’ ecology & distribution?
4) why have species' anatomy & physiology evolved as they have?
Primary Research Systems
I. Polyploidization as Mechanisms of Rapid Physiological Evolution
Polyploidization is the fastest known mechanism of speciation in Eukaryotes. Since its discovery in plants more than 100 years ago, reconciling the empirical evidence of polyploidization as a key driver of evolution with theoretical models that predict polyploids are most often an “evolutionary dead-end” has been one of the most critical problems in plant biodiversity research.
The overall goal of this work is to explain why polyploidization drives physiological evolution and how novel physiological functions impact the ecological and evolutionary success of new polyploid species.
II. Co-ordinated Evolution of Ecology and Physiology Between Independent Life Stages
From deserts and savannas to tropical canopies and cloud forests, ferns exhibit incredible ecological diversity and the independence of the gametophytic and sporophytic life stages makes them unique among major plant groups. Eco-evolutionary theory posits that the separation of life stages also separates selective pressures on organismal function, and the coordination of ecophysiology between life stages impacts the ecological and evolutionary success of fern species.
The overall goal of this work is to explain how gametophyte physiology drives the ecology and distribution of ferns and if/how/why the ecology and physiology of independent life stages are coordinated within species.
III. Paleoclimate Change as a Driver of Ecophysiological Evolution
Cycads are often viewed as relics of primeval times, but this narrative is challenged by recent molecular and fossil evidence showing that extant cycad genera rapidly diversified during the Neogene (~23 Mya) – a period characterized by intense global aridification. Further confounding this story is the seeming stasis in cycad gross morphology despite the recent diversification, which presents an intriguing macroevolutionary puzzle: why and how did cycads experience this rapid diversification?
The overall goal of this work is to investigate the role of climate change in the physiological evolution and diversification of cycads and how physiological function drives spatial biodiversity patterns in cycads.
IV. Extreme Ecophysiological Specialization and the Evolution of Dioecy
Eco-evolutionary theory posits that dioecy may result in unique sex-mediated adaptions related to resource allocation and ecophysiology. Cycads are the earliest diverging lineage of seed plants with strict dioecy, and all cycad species undergo periods of thermogenesis and increase the temperature of their “cones” up to 15 degrees C above ambient to attract pollinators.
The overall goal of this work of the proposed research is to explain the whole-plant ecophysiological costs and reproductive benefits of thermogenesis-mediated pollination in the ancient Cycadales.
