Ellen J. Quinlan, PhD

Eco-evolutionary relationships among congeneric trees

A key driver of the high tree diversity characteristic of tropical Andean forests is the packing of many closely related species across steep elevation gradients. My PhD work with Dr. Miles Silman and the Andes Biodiversity Ecosystem Research Group (ABERG) sought to understand how these lineages diversify and sort into their elevational niches, the degree to which species boundaries are maintained where they co-occur, and how demographic patterns change through time. Much of this work focused on disentangling these relationships among sympatric species in the genus Prunus (cherries).

Quinlan, E.J. and Silman, M.R. Relative effective population sizes and demographic histories of sympatric, congeneric, Andean trees. [In prep].

Quinlan, E.J., Pease, J.B., Sallo Bravo, J., Fuentes, A., Farfan-Rios, W. and Silman, M.R. Upslope diversification and gene flow among congeneric Andean trees. [In prep].

Quinlan, E.J., Layman, C.A. and Silman, M.R. (2025). Climate-Mediated hybridisation and the future of Andean forests. J Biogeogr, 52(3). https://doi.org/10.1111/jbi.15113

Conservation genomics of rare tropical trees

Tropical forests comprise a few hyperdominant and many rare tree species, but distinguishing the truly rare from those simply under-sampled remains a challenge for ecology and conservation. Given the vastness of Amazonia, we will never sample enough individuals to resolve this problem through field data alone, as half of all species are known from three or fewer collections and at least a third of all collections remain unidentified. I am interested in exploring ways we can use genomic tools to leverage the information stored in individuals already sampled to advance our understanding of the rarest Amazonian trees and inform conservation assessments.

Quinlan, E.J., Neill, D.A., Rivas-Torres, G., and Silman, M.R. (2025). Assessing rarity: genomic insights for population assessments and conservation of the most poorly known Neotropical trees. Biological Conservation, 309, 111280. https://doi.org/10.1016/j.biocon.2025.111280

Phylogeography and ecophysiology of Kalmia buxifolia

My MSc. work with Dr. Beverly Collins and Dr. Kathy Mathews focused on characterizing the ecophysiology and evolutionary history of the flowering shrub Kalmia buxifolia. This species is disjunctly distributed across the high-elevation rock outcrops of the southern Appalachians, upper monadnocks and pine savannas of the Carolina Piedmont and Coastal Plain, and the New Jersey Pine Barrens. We used genetic data to reconstruct the phylogeographic history of the species, estimating potential directions and timing of migration as well as dating the divergence from its sister species K. procumbens. Additionally, we used stable isotope and leaf morphology data to assess whether isolation in these different environments has led to variation in intrinsic water-use efficiency.

Quinlan, E.J., Mathews, K. G., Collins, B., & Young, R. (2020). Phylogenetic divergence and ecophysiological variation in the disjunct Kalmia buxifolia (Sand-myrtle, Ericaceae). Systematic botany, 45(4), 900-912. https://doi.org/10.1600/036364420X16033962925277