Summary: vol. 159, no. 6 the american naturalist june 2002
Playing by Different Rules: The Evolution of Virulence in
Kara J. O'Keefe1,* and Janis Antonovics2,
1. Department of Biology, Duke University, Durham, North
2. Department of Biology, University of Virginia, Charlottesville,
Submitted February 7, 2001; Accepted December 1, 2001
abstract: We investigate the evolution of virulence of pathogens
that reduce their hosts' fitness primarily by affecting host fecundity.
We show that, under many conditions, such sterilizing pathogens
evolve high rather than intermediate levels of virulence, and this
pushes the pathogen population and sometimes the host population
toward extinction. We also show that spatial population structure
can reverse this evolutionary result and allow the persistence of
intermediate-virulence pathogens. Thus, spatial population structure
may be vital to the persistence of sterilizing pathogens in nature.
Keywords: disease, evolution of virulence, host-pathogen, individual-
based model, sterilization, spatial population structure.