title: Temporal and spatial mosaics: deep host association and shallow geographic drivers shape genetic structure in a widespread pinworm,Rauschtineria eutamii.
abstract: Climate and host demographic cycling often shape both parasite genetic diversity and host distributions, processes that transcend a history of strict host-parasite association. We explored host associations and histories based on an evaluation of mitochondrial and nuclear sequences to reveal the underlying history and genetic structure of a pinworm,Rauschtineria eutamii, infecting 10 species of western North American chipmunks (Rodentia:Tamias, subgenusNeotamias).Rauschtineria eutamiicontains divergent lineages influenced by the diversity of hosts and variation across the complex topography of western North America. We recovered six reciprocally monophyleticR. eutamiimitochondrial clades, largely supported by nuclear gene trees, exhibiting divergence levels comparable to intraspecific variation reported for other nematodes. Phylogenetic relationships among pinworm clades suggest thatR. eutamiicolonized an ancestral lineage of western chipmunks and lineages persisted during historical isolation in divergingNeotamiasspecies or species groups. Pinworm diversification, however, is incongruent and asynchronous relative to host diversification. Secondarily, patterns of shallow divergence were shaped by geography through events of episodic colonization reflecting an interaction of taxon pulses and ecological fitting among assemblages in recurrent sympatry. Pinworms occasionally infect geographically proximal host species; however, host switching may be unstable or ephemeral, as there is no signal of host switching in the deeper history ofR. eutamii.
authors.affiliation: Department of Biology, Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico 87108, USA.
authors.forename: Kayce C
authors.initials: KC
authors.lastname: Bell
authors.affiliation: Environmental Science, Policy, & Management, University of California, Berkeley, Berkeley, California 94720, USA.
authors.forename: Kendall L
authors.initials: KL
authors.lastname: Calhoun
authors.affiliation: US National Parasite Collection, USDA, Agricultural Research Service, Beltsville Area Research Center, BARC East 1180, 10300 Baltimore Avenue, Beltsville, Maryland 20715, USA.
authors.forename: Eric P
authors.initials: EP
authors.lastname: Hoberg
authors.affiliation: Department of Zoology, Denver Museum of Nature & Science, 2001 Colorado Boulevard, Denver, Colorado 80205, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Demboski
authors.affiliation: Department of Biology, Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico 87108, USA.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Cook
keywords: Tamias; chipmunk; ecological fitting; parasite; phylogeography; taxon pulse; western North America