Figure 2.

Total densities for bacteria and ciliates. Rows represent data from the three different population structures: (a–c) full-diversity, (d–f) high-diversity and (g–i) ancestral P. fluorescens strain without diversity. Columns represent the three different predation treatments: (a,d,g) ciliates coevolved with bacteria, (b,e,h) naive ciliate and (c,f,i) no ciliates. Orange lines and points (mean ± s.e.) show total bacterial density measured by absorbance, and blue lines and squares represent ciliate densities (mean ± s.e.). Bacterial density is shown as optical density at 600 nm, and ciliate density as cells ml^–1, both normalized to 0–1 range.