Spatial heterogeneity and the stability of host‐parasite coexistence

Spatially heterogeneous environments can theoretically promote more stable coexistence of hosts and parasites by reducing the risk of parasite attack either through providing permanent spatial refuges or through providing ephemeral refuges by reducing dispersal. In experimental populations of Pseudomonas aeruginosa and the bacteriophage PP7, spatial heterogeneity promoted stable coexistence of host and parasite, while coexistence was significantly less stable in the homogeneous environment. Phage populations were found to be persisting on subpopulations of sensitive bacteria. Transferring populations to fresh microcosms every 24 h prevented the development of permanent spatial refuges. However, the lower dispersal rates in the heterogeneous environment were found to reduce parasite transmission thereby creating ephemeral refuges from phage attack. These results suggest that spatial heterogeneity can stabilize an otherwise unstable host‐parasite interaction even in the absence of permanent spatial refuges.

[1]  R. Lenski.  Quantifying fitness and gene stability in microorganisms. , 1991, Biotechnology.

[2]  D. Pimentel,et al.  Space-Time Structure of the Environment and the Survival of Parasite-Host Systems , 1963, The American Naturalist.

[3]  F. M. Stewart,et al.  A Complex Community in a Simple Habitat: An Experimental Study with Bacteria and Phage , 1977 .

[4]  Paul B Rainey,et al.  Antagonistic coevolution between a bacterium and a bacteriophage , 2002, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[5]  R M Nisbet,et al.  Habitat structure and population persistence in an experimental community , 2001, Nature.

[6]  Michael Travisano,et al.  Adaptive radiation in a heterogeneous environment , 1998, Nature.

[7]  R. Hilborn,et al.  The effect of spatial heterogeneity on the persistence of predator-prey interactions. , 1975, Theoretical population biology.

[8]  J. F. Atkins,et al.  Nucleotide sequence of a single-stranded RNA phage from Pseudomonas aeruginosa: kinship to coliphages and conservation of regulatory RNA structures. , 1995, Virology.

[9]  A. Buckling,et al.  The effect of spatial heterogeneity and parasites on the evolution of host diversity , 2004, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[10]  M. Baalen,et al.  Antagonistic Coevolution over Productivity Gradients , 1998, The American Naturalist.

[11]  A. Sasaki,et al.  The evolution of parasite virulence and transmission rate in a spatially structured population. , 2000, Journal of theoretical biology.

[12]  A. Buckling,et al.  Population mixing accelerates coevolution , 2003 .

[13]  M. Hassell,et al.  Metapopulation structures affect persistence of predator–prey interactions , 2002 .

[14]  W. Murdoch.  Stabilizing effects of spatial heterogeneity in predator-prey systems. , 1977, Theoretical population biology.

[15]  M. Holyoak,et al.  Habitat Patch Arrangement and Metapopulation Persistence of Predators and Prey , 2000, The American Naturalist.

[16]  A. Sasaki,et al.  ‘Small worlds’ and the evolution of virulence: infection occurs locally and at a distance , 1999, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[17]  P. Hosseini.  How Localized Consumption Stabilizes Predator‐Prey Systems with Finite Frequency of Mixing , 2003, The American Naturalist.

[18]  C. Huffaker.  Experimental studies on predation : dispersion factors and predator-prey oscillations , 1958 .

[19]  J. Mittler,et al.  Host-Parasite Coexistence: The Role of Spatial Refuges in Stabilizing Bacteria-Phage Interactions , 1996, The American Naturalist.

[20]  S. Jørgensen.  Models in Ecology , 1975 .

[21]  M. Holyoak,et al.  Persistence of an Extinction-Prone Predator-Prey Interaction Through Metapopulation Dynamics , 1996 .

[22]  J. Burdon,et al.  Evolution of gene‐for‐gene systems in metapopulations: the effect of spatial scale of host and pathogen dispersal , 2002 .

[23]  A. Buckling,et al.  The effect of a bacteriophage on diversification of the opportunistic bacterial pathogen, Pseudomonas aeruginosa , 2005, Proceedings of the Royal Society B: Biological Sciences.

[24]  M. Begon,et al.  Life-history trade-offs and the evolution of pathogen resistance: competition between host strains , 1994, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[25]  L. Luckinbill,et al.  Coexistence in Laboratory Populations of Paramecium Aurelia and Its Predator Didinium Nasutum , 1973 .

[26]  L. Chao,et al.  Mechanisms of coexistence of a bacteria and a bacteriophage in a spatially homogeneous environment , 2003 .

[27]  R. Lenski,et al.  Constraints on the Coevolution of Bacteria and Virulent Phage: A Model, Some Experiments, and Predictions for Natural Communities , 1985, The American Naturalist.

[28]  J. Thompson,et al.  Specific Hypotheses on the Geographic Mosaic of Coevolution , 1999, The American Naturalist.

[29]  R. Lenski,et al.  Linking genetic change to community evolution: insights from studies of bacteria and bacteriophage , 2000 .