Levels of selective pressure in C. impatiens and C. resedifolia orthologous genes. Mean values of ω are reported for genes functionally characterized as cold responsive (CRG), and for genes annotated as involved in cold response (CGO), photosynthesis (PGO) and general stress responses (SGO). Text in bars denotes the number of genes; error bars denote the standard error of the mean. For each functional class, the mean residual values of the correlation between levels of selective pressure and A. thaliana gene length were compared to the mean estimated for the genes not in such functional class (identified by red dots) using a Wilcoxon test: * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001.
Ometto et al. BMC Evolutionary Biology 2012 12:7 doi:10.1186/1471-2148-12-7