About Dr. Jason Sexton
Research Interests
I apply an evolutionary perspective and a collaborative interdisciplinary approach to pressing questions in ecology. I use field and growth chamber experiments, genetic analyses, environmental modeling, physiological analyses, and biogeographic datasets to address these questions. Although I focus primarily on plant climate adaptation, I also actively contribute to research on sustainability science, from biological invasions, and maximizing species diversity under climate change, to the role of sociocultural adaptive capacity in biological conservation. My research is driven by urgent questions, and is grounded in empirical study to test, enhance, and expand ecological theory.
Ecology and evolution of species range limits
I study Mimulus (monkeyflower) species, among other plant groups, to understand (1) niche evolution and the underpinnings of distributions, (2) adaptations, tolerances, and evolutionary potentials to adapt to varying environments and (3) consequences of historical and experimental gene flow on these processes. I examine the role of selection, gene flow, and range limits in determining adaptive phenotypes in the endemic California Sierra Nevada annual plant, Mimulus laciniatus, across its species range (see past research highlights at UC Davis Department of Plant Sciences and IGERT REACH). Populations across a 2300 m elevation gradient have been examined in common gardens representing the climate breadth of the species range, and beyond. Population genetics/genomics are being used to understand adaptive responses in the context of gene flow. Continuing research includes climate-based and local-scale niche evolution and niche convergence among closely related species and their genomic basis.
Adaptation in novel environments
In collaboration with Ary Hoffmann at the University of Melbourne I am investigating plants restricted to the Australian Alps and focusing on species range size and the role of gene flow on the processes of adaptation and tolerance to rapidly changing environments. The performance of alpine plants are being tested under a variety of conditions representing different types of environmental stress. This comparative study includes a variety of alpine Australian plant groups, including native grasses, sedges, and forbs.
Global change and sustainability science
I am fascinated, and motivated, by the question of how to manage ecosystems sustainably in the face of global change, and I enjoy collaborating across traditional research fields. I have collaborated within the Biological Impacts of Climate Change in California Program (BICCCA) where I researched ways to incorporate evolutionary theory in ecosystem management under climate change. Additionally, I have participated as a Climate Action Team member for the California Climate Change Center where I reviewed potential risks from biological invasions on agricultural systems.
I was a trainee in the NSF Biological Invasions IGERT program, where I co-investigated the practical and social aspects that govern weed management, specifically yellow starthistle, in the Sierran foothill ranching community (see research highlight). I have also participated in the NSF Responding to Rapid Environmental Change (REACH) IGERT program, investigating the link between human cultural adaptive capacity and biological conservation with ecologists and anthropologists at UC Davis.