Diversification in temporally heterogeneous environments: effect of the grain in experimental bacterial populations

Authors

  • P. A. VENAIL,

    1. Université Montpellier 2, Institut des Sciences de l’Evolution, UMR CNRS-UM2-IRD 5554, CC 065, Place Eugène Bataillon, Montpellier Cedex 05, France
    2. Universidad de los Andes, Centro de Investigaciones Microbiológicas CIMIC, Carrera 1 No 18A-10, Bogotá, Colombia
    Search for more papers by this author
  • O. KALTZ,

    1. Université Montpellier 2, Institut des Sciences de l’Evolution, UMR CNRS-UM2-IRD 5554, CC 065, Place Eugène Bataillon, Montpellier Cedex 05, France
    Search for more papers by this author
  • I. OLIVIERI,

    1. Université Montpellier 2, Institut des Sciences de l’Evolution, UMR CNRS-UM2-IRD 5554, CC 065, Place Eugène Bataillon, Montpellier Cedex 05, France
    Search for more papers by this author
  • T. POMMIER,

    1. Laboratoire Ecosystèmes Lagunaires, Université Montpellier 2, UMR CNRS-UM2-Ifremer-IRD 5119, CC 093, Place Eugène Bataillon, Montpellier Cedex 05, France
    Search for more papers by this author
    • Present address: Laboratoire d’Ecologie Microbienne (UMR 5557, USC 1193), Université Lyon I, INRA, CNRS, bât. G. Mendel, 43 boulevard du 11 novembre 1918, 69622 Villeurbanne, France.

  • N. MOUQUET

    1. Université Montpellier 2, Institut des Sciences de l’Evolution, UMR CNRS-UM2-IRD 5554, CC 065, Place Eugène Bataillon, Montpellier Cedex 05, France
    Search for more papers by this author

Patrick A. Venail, Universidad de los Andes, Centro de Investigaciones Microbiológicas CIMIC, Carrera 1 No 18A-10, Bogotá, Colombia.
Tel.: +57(1) 3394949 ext. 3754; fax: +57(1) 3324368; e-mails: pa.venail24@uniandes.edu.co, venailzo@umich.edu
Nicolas Mouquet, Université Montpellier 2, Institut des Sciences de l’Evolution, UMR CNRS-UM2-IRD 5554, CC 065, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France.
Tel.: +33(4) 67 14 93 57; fax: +33(4)4 67 04 20 32; e-mail: nmouquet@univ-montp2.fr

Abstract

Although theory established the necessary conditions for diversification in temporally heterogeneous environments, empirical evidence remains controversial. One possible explanation is the difficulty of designing experiments including the relevant range of temporal grains and the appropriate environmental trade-offs. Here, we experimentally explore the impact of the grain on the diversification of the bacterium Pseudomonas fluorescens SBW25 in a temporally fluctuating environment by including 20 different pairs of environments and four temporal grains. In general, higher levels of diversity were observed at intermediate temporal grains. This resulted in part from the enhanced capacity of disruptive selection to generate negative genotypic correlations in performance at intermediate grains. However, the evolution of reciprocal specialization was an uncommon outcome. Although the temporal heterogeneity is in theory less powerful than the spatial heterogeneity to generate and maintain the diversity, our results show that diversification under temporal heterogeneity is possible provided appropriate environmental grains.

Ancillary