Historical biogeography among species of Varestrongylus lungworms (Nematoda: Protostrongylidae) in ungulates: episodic expansion and host colonization linking Eurasia and North America.

摘要: Varestrongylus lungworms (Nematoda: Protostrongylidae) include 10 nominal species that parasitize wild and domesticated artiodactyles. Eight are endemic to the western Palearctic Eurasia, whereas two limited in distribution Nearctic. Complex host associations, primarily among Cervidae Bovidae (Caprinae), biogeography were explored based on direct comparisons of parasite phylogenies reveal historical development this fauna. Diversification has an intricate history extending over Pliocene Quaternary involving episodic processes for geographic colonization: (1) origins Eurasia with independent expansion events into bordering ecozones; (2) cervids ancestral hosts; (3) caprine-associated V. pneumonicus is basal a result colonization event; (4) secondary diversification, linked sequential events, occurred within (V. sagittatus + V. tuvae; alpenae; capreoli, alces + V. eleguneniensis); (5) at least additional caprines occurred, followed or not by diversification qinghaiensis + V. longispiculatus; capricola, respectively); (6) North America from late early Pleistocene postulated alpenae, eleguneniensis). Comparisons phylogenetic hypotheses derived comparative morphology molecular inference these nematodes consistent coevolutionary biogeographic history. Episodes colonization, often relation rapid shifts climate habitat perturbation, have dominated Varestrongylus.