dataTab-delimited text file with column headings. Full methods are described in smith (2010) Evolution 65: 831-841. Briefly: "plasmid.treatment" is the source from which the plasmid was sampled (immigration line, no.immigration line, or the ancestral plasmid genotype). "selection.coefficient" is a measure of the fitness of plasmid-infected strains in competition against a common plasmid-resistant competitor. "infection.constant" is a measure of the plasmid's ability to infect uninfected bacteria of the ancestral genotype. "superinfection.constant" is a measure of the palsmid's ability to infect bacteria infected with an incompatible competitor plasmid. "ratio.super.to.infect" is the ratio of the two constants (the values in the figure this data was used for). "NA" values indicate missing data.

In a recent study of the symbiosis between bacteria and plasmids, the available evidence suggests that experimental evolution of plasmid virulence was primarily driven by within-host competition caused by superinfection. The data do not exclude the possibility, however, that a trade-off between virulence and infectious transmission to uninfected bacteria also played a minor role.