Sequence similarity (fraction of identical pairs) dependence of F
in the root node set. Alignments were grouped into sequence similarity bins of size 0.1 and then the alignments within each bin were grouped according to its CD name for averaging. The avearge Fcar values are shown with the scale on the left y-axis: open symbols, Fcar(8); closed symbols, Fcar(0). The x-axis shows the midpoint of each sequence similarity bin. The histogram (grey bars) shows the number of superfamilies in each bin with the scale on the right y-axis.