title: Diversification in temporally heterogeneous environments: effect of the grain in experimental bacterial populations.
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.
authors: Université Montpellier 2, Institut des Sciences de l'Evolution, UMR CNRS-UM2-IRD 5554, CC 065, Place Eugène Bataillon, Montpellier Cedex 05, France. pa.venail24@uniandes.edu.co
authors: P A
authors: PA
authors: Venail
authors: O
authors: O
authors: Kaltz
authors: I
authors: I
authors: Olivieri
authors: T
authors: T
authors: Pommier
authors: N
authors: N
authors: Mouquet
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics; D005075:Biological Evolution; D003198:Computer Simulation; D004777:Environment; D049810:Genetic Speciation; D014644:Genetic Variation; D005838:Genotype; D008954:Models, Biological; D011551:Pseudomonas fluorescens / Q000235:genetics / Q000502:physiology*; D012641:Selection, Genetic; D013997:Time Factors