Competition–dispersal tradeoff ecologically differentiates recently speciated marine bacterioplankton populations

Abstract

Significance: The resource landscape for marine microbes is composed of microscale resource patches, but whether this microheterogeneity can drive the ecological differentiation of natural microbial populations remains unclear. The tradeoff between two nascent populations of marine bacteria demonstrated here is significant for several reasons. First, it illustrates that principles of spatial ecology, so far only illustrated for animals and plants, apply to the ephemeral, microscale nutrient landscape of marine microbes. Second, the results suggest that differential behavior can ensure coexistence of otherwise very similar populations of organisms. Finally, because the demonstrated tradeoff induces microgeographic separation among the populations, it may be a crucial step in initiating gene flow barriers that ultimately allow the populations to embark on differential evolutionary trajectories.