Data from: Phylogenetic context determines the role of competition in adaptive radiation

Understanding ecological mechanisms regulating the evolution of
biodiversity is of much interest to ecologists and evolutionary
biologists. Adaptive radiation constitutes an important evolutionary
process that generates biodiversity. Competition has long been thought to
influence adaptive radiation, but the directionality of its effect and
associated mechanisms remain ambiguous. Here, we report a rigorous
experimental test of the role of competition on adaptive radiation using
the rapidly evolving bacterium Pseudomonas fluorescens SBW25 interacting
with multiple bacterial species that differed in their phylogenetic
distance to the diversifying bacterium. We showed that the inhibitive
effect of competitors on the adaptive radiation of P. fluorescens
decreased as their phylogenetic distance increased. To explain this
phylogenetic dependency of adaptive radiation, we linked the phylogenetic
distance between P. fluorescens and its competitors to their niche and
competitive fitness differences. Competitive fitness differences, which
showed weak phylogenetic signal, reduced P. fluorescens abundance and thus
diversification, whereas phylogenetically conserved niche differences
promoted diversification. These results demonstrate the context dependency
of competitive effects on adaptive radiation, and highlight the importance
of past evolutionary history for ongoing evolutionary processes.