I'm interested in the ecology and evolution of interactions within microbial communities. My work focuses in particular on interactions between bacteria and the many and various mobile genetic elements that inhabit them, such as conjugative plasmids (infectious loops of DNA) and phages (bacterial viruses).


These elements are extremely interesting for evolutionary biologists; Some elements are purely antagonistic, such as the lytic phages, viruses which infect bacteria and then kill them in order to reproduce. The lytic phage- bacteria interaction is characterised by rapid, antagonistic coevolution where phages cause selection for resistance in the bacteria which in turn selects for infectivity in the phage and so on and so forth. On the other hand elements such as plasmids and temperate phages (viruses which insert their own genome into that of the bacteria) can be beneficial to their hosts. They can carry genes encoding traits which can be helpful to the bacteria in particular environments, such as toxin resistance genes. However these elements are not purely benevolent, in order to persist they rely on host resources so, when the bacteria does not require the genes they carry, they too are essentially parasitic.


I'm interested in how any why these elements persist and how the evolution of this unseen diversity of elements can drive changes in the bacterial population which echo through communities.


Ellie harrison, P3 Fellow, University of Sheffield



Follow me on twitter for conference adventures: @ellieevolves


plasmid papers

Hall & Harrison (2016) Bacterial evolution: Resistance is a numbers game, Nature Microbiology

Hall, Wood, Harrison & Brockhurst (2016) Source–sink plasmid transfer dynamics maintain gene mobility in soil bacterial communities, PNAS

Harrison, Dytham, Hall, Guymer, Spiers, Paterson & Brockhurst (2016) Rapid compensatory evolution promotes the survival of conjugative plasmids, Mobile genetic elements

Kottara, Hall, Harrison & Brockhurst (2016) Multi-host environments select for host-generalist conjugative plasmids, BMC evolutionary biology

Harrison, Truman, Wright, Spiers, Paterson & Brockhurst (2015) , Plasmid carriage can limit bacteria-phage coevolution, Biology letters

Harrison, Guymer, Spiers, Paterson & Brockhurst (2015) Parallel Compensatory Evolution Stabilizes Plasmids across the Parasitism-Mutualism Continuum, Current Biology

Harrison, Wood, Dytham, Pitchford, Truman, Spiers, Paterson, Brockhurst (2015) Bacteriophages limit the existance conditions for conjugative plasmids, mBio

Hall, Harrison, Lilley, Paterson, Spiers and Brockhurst (2015) Environmentally co-occurring mercury resistance plasmids are genetically and phenotypically diverse and confer variable context-dependent fitness effects, Environmental Microbiology

Harrison, Koufapanou, MacLean, & Burt (2014) Sex drives intracellular conflict in yeast, Journal of Evolutionary Biology ***Winner of the Stearns Graduate Student Prize 2015 ****

Harrison, & Brockhurst (2012) Plasmid-mediated horizontal gene transfer is a coevolutionary process. Trends in Microbiology

Harrison, Koufopanou, Burt & MacLean (2012) The Cost of Copy Number in a Selfish Genetic element: The 2μm Plasmid of Saccharomyces cerevisiae, Journal of Evolutionary Biology