FIG. 7.—

Relationship of the RCA and the V/m ratio of binding sites of the transcription factors in the methionine pathway of yeast. The letters in the graph refer to the clade labels in figure 8. Whereas for the youngest clade F the V/m ratios for all transcription factors are less than 1, the ratios tends to be large for older clades but still have a considerable variation among binding site classes. Note that V/m ratios larger than 1 suggest heterogeneity of binding site number among taxa.