I am an evolutionary biologist seeking to understand how interactions among species generate and maintain much of the diversity we see on earth. My work is focused primarily on host – pathogen coevolution, but with a building interest in the role that the microbiome might play in affecting this interaction. Using a number of bacteriophage - bacteria – plant systems, I have been working to address questions relating to the spatial and temporal scales of pathogen adaptation to their hosts, the impact of coevolutionary dynamics on community diversity, and the influence phages might play in altering the phenotype of their bacterial hosts in meaningful ways, for example by selecting for decreased virulence to eukaryotes.
Culturable microbial community from the
surface of horse chestnut leaf after 24 hour
incubation on King’s Broth media plates.
Through a combination of field studies on natural populations with experimental evolution studies performed in greenhouses or in the laboratory, I aim to identify patterns of pathogen-mediated selection in nature and then to test the underlying process in a more controlled environment. For example, although we have known for some time that bacteria and their phages coevolve in test tubes in the laboratory, I recently sampled bacteria and phage communities from horse chestnut trees over space and time to show that they also coevolve in nature.
Koskella, B. & Brockhurst, M.A. 2014. Bacteria–phage coevolution as a driver of ecological and evolutionary processes in microbial communities. FEMS Microbiol Rev (online early).
Koskella B. 2014. Bacteria-phage interactions across time and space: Merging local adaptation and time-shift experiments to understand phage evolution. Am Nat 184: S9-S21.
Koskella, B. 2013. Phage-mediated selection on microbiota of a long-lived host. Curr Biol 23:1256–1260.
Koskella, B., Thompson, J.N., Preston, G.M. & Buckling, A. 2011. Local biotic environment shapes the spatial scale of bacteriophage adaptation to bacteria. Am Nat 177:440-51.
Koskella, B. and C.M. Lively. 2009. Evidence for negative frequency-dependent selection during experimental coevolution of a freshwater snail and a sterilizing trematode. Evolution 63:2213-2221.