FIG 1.

Correlation between cell volume measurements obtained using microscopy and Coulter counter. Volumes obtained by microscopy are expressed in arbitrary units (a.u.) proportional to femtoliters (i.e., cubic micrometers); volumes obtained using the Coulter counter are expressed in femtoliters. Each point shows the grand median of three assays for clones sampled from the 12 evolving populations or of six assays for the two ancestral strains. Kendall’s coefficient τ = 0.5495, n = 38, and P < 0.0001.