Figure 6.

Graph plotting the evolutionary rate against the node age for (a) A1 and AICDA sequences and (b) A3Z1, A3Z2 and A3Z3 sequences. Colour code in the inset. Values for the goodness and significance of the fit to a straight line are provided. For the A1 genes, the values with and without the indicated point ($) are given. When this value is not included in the analysis the trend is not statistically significant.