Mycoplasma gallisepticum infection of house finches is partly supported by high densities of finches maintained by bird feeders. These bird feeders also facilitate parasite transmission. Figure drawn by John Megahan.

Do humans influence evolution in emerging disease systems? Undoubtedly.

“Human drivers of ecological and evolutionary dynamics in emerging and disappearing infectious disease systems,” was published in Philosophical Transactions of the Royal Society B, Dec. 5, 2016 by lead author Mary Rogalski, a postdoctoral fellow in the lab of Professor Meghan Duffy. Coauthors include graduate students Camden Gowler and Clara Shaw, Ruth Hufbauer, a colleague at Colorado State University, and Duffy.

According to the paper summary, humans alter ecological and evolutionary host-parasite interactions on contemporary timescales. Humans increase host and parasite dispersal, promoting infection in naïve host populations and host switches. Urbanization and agriculture can support particularly high population densities of hosts, which has the potential to drive the evolution of higher virulence in parasites. Human activities – including habitat fragmentation, hunting, and agriculture – can reduce host genetic diversity, which limits the potential for the host to evolve in response to parasites. At the same time, human impacts on the abiotic environment (especially temperature and chemical pollution) can favor disease emergence. Further, evolution can thwart disease management and biocontrol. Finally, in rare cases, humans influence evolution via disease eradication. Understanding and controlling disease outbreaks will require considering widespread anthropogenic influences on host and parasite evolutionary trajectories.

John Megahan, EEB’s scientific illustrator, drew artwork for the paper.