title: Host population bottlenecks drive parasite extinction during antagonistic coevolution.
abstract: Host-parasite interactions are often characterized by large fluctuations in host population size, and we investigated how such host bottlenecks affected coevolution between a bacterium and a virus. Previous theory suggests that host bottlenecks should provide parasites with an evolutionary advantage, but instead we found that phages were rapidly driven to extinction when coevolving with hosts exposed to large genetic bottlenecks. This was caused by the stochastic loss of sensitive bacteria, which are required for phage persistence and infectivity evolution. Our findings emphasize the importance of feedbacks between ecological and coevolutionary dynamics, and how this feedback can qualitatively alter coevolutionary dynamics.
authors.affiliation: ESI, Biosciences, University of Exeter, Penryn Campus, Penryn, TR10 9FE, United Kingdom. elzehesse@gmail.com.
authors.forename: Elze
authors.initials: E
authors.lastname: Hesse
authors.affiliation: ESI, Biosciences, University of Exeter, Penryn Campus, Penryn, TR10 9FE, United Kingdom.
authors.forename: Angus
authors.initials: A
authors.lastname: Buckling
mesh_terms: D005075:Biological Evolution; D053476:Extinction, Biological; D054884:Host-Pathogen Interactions; D017105:Pseudomonas Phages / Q000502:physiology*; D011551:Pseudomonas fluorescens / Q000502:physiology* / Q000821:virology*
keywords: Coevolutionary asymmetry; genetic drift; host diversity; local adaptation; population size; stochasticity