Lauren Carley
University of Chicago
I am an evolutionary ecologist interested in the causes and consequences of intraspecific variation in plants. I will be starting as an Assistant Professor in the Department of Ecology & Evolution at the University of Chicago in September 2024. My postdoctoral work with Dave Moeller at the University of Minnesota addressed how microevolutionary trait change and fine-scale local adaptation influence speciation in Clarkia xantiana (Onagraceae), an annual California wildflower. My dissertation work with Tom Mitchell-Olds and Bill Morris at Duke University focused on understanding the evolution of diverse chemical defenses in Boechera stricta (Brassicaceae), a wild relative of Arabidopsis.
Poster number
9
Research interests: evolutionary ecology, intraspecific variation, plant-insect interactions, chemical ecology
Abstract: Traits showing elevated divergence across sister taxa are often hypothesized to drive speciation. However, comparative studies identifying such patterns cannot distinguish whether divergence of focal traits actively drove speciation, or merely occurred after the fact. In this study, we leveraged a tractable pair of incipient wildflower species to directly test how local adaptation and natural selection contribute to speciation. First, we transplanted the two subspecies into their own and each other’s microhabitats to test for small-scale local adaptation (tens of meters) in two secondary contact zones. Second, we planted 145 recombinant inbred lines into the same microhabitats to measure patterns of natural selection in secondary contact, testing whether the direction and/or phenotypic targets of selection vary across the subspecies’ microhabitats in secondary contact. Here, we show that fine-scale local adaptation may promote spatial segregation in sympatry and reduce the likelihood of hybridization between subspecies, promoting speciation. Furthermore, these data show that phenotypic targets of selection may differ across subspecies' microhabitats in sympatry. Thus, selection by both biotic and abiotic drivers (e.g. pollinators and drought) may jointly contribute to subspecies divergence and maintenance of incipient species boundaries in this system.