title: Evolution of virulence: interdependence, constraints, and selection using nested models.
abstract: Natural selection acts on virus populations at two distinct but interrelated levels: within individual hosts and between them. Studies of the evolution of virulence typically focus on selection acting at the epidemiological or between-host level and demonstrate the importance of trade-offs between disease transmission and virulence rates. Within-host studies reach similar conclusions regarding trade-offs between transmission and virulence at the level of individual cells. Studies which examine selection at both scales assume that between- and within-host selection are necessarily in conflict. We explicitly examine these ideas and assumptions using a model of within-host viral dynamics nested within a model of between-host disease dynamics. Our approach allows us to evaluate the direction of selection at the within- and between-host levels and identify situations leading to conflict and accord between the two levels of selection.
authors.affiliation: Department of Ecology and Evolutionary Biology, 569 Dabney Hall, University of Tennessee, Knoxville, 37996-1610, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Gilchrist
authors.forename: Daniel
authors.initials: D
authors.lastname: Coombs
mesh_terms: D006790:Host-Parasite Interactions; D006801:Humans; D008957:Models, Genetic; D012641:Selection, Genetic; D014774:Virulence / Q000235:genetics; D014780:Viruses / Q000235:genetics / Q000472:pathogenicity*