Data from: Conflicting selection alters the trajectory of molecular evolution in a tripartite bacteria–plasmid–phage interaction

Bacteria engage in a complex network of ecological interactions, which
includes mobile genetic elements (MGEs) such as phages and plasmids. These
elements play a key role in microbial communities as vectors of horizontal
gene transfer but can also be important sources of selection for their
bacterial hosts. In natural communities, bacteria are likely to encounter
multiple MGEs simultaneously and conflicting selection among MGEs could
alter the bacterial evolutionary response to each MGE. Here, we test the
effect of interactions with multiple MGEs on bacterial molecular evolution
in the tripartite interaction between the bacterium, Pseudomonas
fluorescens, the lytic bacteriophage, SBW25φ2, and conjugative plasmid,
pQBR103, using genome sequencing of experimentally evolved bacteria. We
show that individually, both plasmids and phages impose selection leading
to bacterial evolutionary responses that are distinct from bacterial
populations evolving without MGEs, but that together, plasmids and phages
impose conflicting selection on bacteria, constraining the evolutionary
responses observed in pairwise interactions. Our findings highlight the
likely difficulties of predicting evolutionary responses to multiple
selective pressures from the observed evolutionary responses to each
selective pressure alone. Understanding evolution in complex microbial
communities comprising many species and MGEs will require that we go
beyond studies of pairwise interactions.