Consistency of the constrained data set used to calculate AI values. (A) The figure illustrates the effect of the number of genes included in the AI-values. The significant differences in the AI values are stable when more than 150 genes are included. (B) 150 genes were resampled randomly and the AIs calculated for the indicated organisms (1 – 8). AI values were calculated for the 150 most strongly (9, as revealed by the number of ESTs in a contig) and weakly (10, only single ESTs) expressed genes.