Fig. 1

Variation in effective population size (Ne) across bacteria. The effective population size of each bacterial species is estimated from the average dS/dN, normalized across species by considering a common set of universally distributed genes (outer circle) for strains within a species whose divergence at synonymous sites were in the range of 0.1 ≤ dS ≤ 0.3. Grey shading denotes those species that do not contain strains within the considered divergence range of dS values. Bacterial lifestyles are indicated in the inner circle. The maximum likelihood tree was built on the concatenate of prokaryote-universal proteins with one representative strain for each species. The scale bar indicates the substitution rate per site. The major prokaryote clades are indicated in the tree (clockwise): A: Archaea, M: Mycoplasma, F: Fusobacteria, Ac: Actinobacteria, D: Dehalococcoides, Cy: Cyanobacteria/Melainabacteria, S: Spirochaetia, C: Chlamydiae, B: Bacteroidetes/Chlorobi, δ/ε: Delta- and Epsilonproteobacteria, α: Alphaproteobacteria, β: Betaproteobacteria, γ: Gammaproteobacteria