title: Understanding Host-Switching by Ecological Fitting.
abstract: Despite the fact that parasites are highly specialized with respect to their hosts, empirical evidence demonstrates that host switching rather than co-speciation is the dominant factor influencing the diversification of host-parasite associations. Ecological fitting in sloppy fitness space has been proposed as a mechanism allowing ecological specialists to host-switch readily. That proposal is tested herein using an individual-based model of host switching. The model considers a parasite species exposed to multiple host resources. Through time host range expansion can occur readily without the prior evolution of novel genetic capacities. It also produces non-linear variation in the size of the fitness space. The capacity for host colonization is strongly influenced by propagule pressure early in the process and by the size of the fitness space later. The simulations suggest that co-adaptation may be initiated by the temporary loss of less fit phenotypes. Further, parasites can persist for extended periods in sub-optimal hosts, and thus may colonize distantly related hosts by a "stepping-stone" process.
authors.affiliation: Laboratório de Ecologia Molecular e Parasitologia Evolutiva, Universidade Federal do Paraná, Caixa Postal 19073, Curitiba, PR 81531-980, Brazil; Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, Curitiba, PR 81531-980, Brazil.
authors.forename: Sabrina B L
authors.initials: SB
authors.lastname: Araujo
authors.affiliation: Laboratório de Ecologia Molecular e Parasitologia Evolutiva, Universidade Federal do Paraná, Caixa Postal 19073, Curitiba, PR 81531-980, Brazil.
authors.forename: Mariana Pires
authors.initials: MP
authors.lastname: Braga
authors.affiliation: Laboratório de Ecologia Molecular e Parasitologia Evolutiva, Universidade Federal do Paraná, Caixa Postal 19073, Curitiba, PR 81531-980, Brazil.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Brooks
authors.affiliation: Center for Environmental Studies and Department of Biology, Virginia Commonwealth University, Richmond, VA, United States of America.
authors.forename: Salvatore J
authors.initials: SJ
authors.lastname: Agosta
authors.affiliation: US National Parasite Collection, US Department of Agriculture, Agricultural Research Service, BARC East No. 1180, Beltsville, MD, United States of America.
authors.forename: Eric P
authors.initials: EP
authors.lastname: Hoberg
authors.affiliation: Pós-Graduação em Ecologia e Conservação, Setor de Ciências Biológicas, Caixa Postal 19031, Curitiba, PR, 81531-990, Brazil.
authors.forename: Francisco W
authors.initials: FW
authors.lastname: von Hartenthal
authors.affiliation: Laboratório de Ecologia Molecular e Parasitologia Evolutiva, Universidade Federal do Paraná, Caixa Postal 19073, Curitiba, PR 81531-980, Brazil.
authors.forename: Walter A
authors.initials: WA
authors.lastname: Boeger
mesh_terms: D000818:Animals; D004463:Ecology; D006790:Host-Parasite Interactions