Fig. 3.
Observed or simulated fractions of genes showing expression reversion (CRV) and reinforcement (CRI), respectively. (A) Observed CRV and CRI in seven parallel experiments of Escherichia coli undergoing laboratory evolution in a glycerol medium. The equality in the percentage of RI and RV genes in each adaptation is tested by a two-tailed binomial test. *, P < 0.05; **, P < 10−10; ***, P < 10−100. (B) Observed CRV and CRI in seven parallel experiments of E. coli undergoing laboratory evolution in a lactate medium. (C) Observed CRV and CRI in two parallel experiments of guppies undergoing evolution in low-predation streams. (D) Observed CRV and CRI in six parallel experiments of E. coli undergoing laboratory evolution in 42 °C. (E) Observed CRV and CRI in 12 parallel experiments of yeast undergoing laboratory evolution in a xylulose medium. (F) Observed CRV − CRI in E. coli adaptations to a glycerol medium, compared with the expected values under the null hypothesis of no gene expression changes. The observed values from 7 parallel experiments are indicated by triangles, whereas the expected values estimated by 100 simulations are presented as frequency distributions using bars. The simulations use the distributions of mean (μ) and CV estimated from the actual data. Two dashed lines depict the 2.5th and 97.5th percentiles in the distribution. (G) Observed CRV − CRI in E. coli adaptations to a lactate medium, compared with the expected values under the null hypothesis of no gene expression changes. (H) Observed CRV − CRI in guppy adaptations to low-predation streams, compared with the expected values under the null hypothesis of no gene expression changes. (I) Observed CRV − CRI in E. coli adaptations to 42 °C, compared with the expected values under the null hypothesis of no gene expression changes. (J) Observed CRV − CRI in yeast adaptations to a xylulose medium, compared with the expected values under the null hypothesis of no gene expression changes.