Fig. 2.

Empirical description of the relationship between rate measurement timescale (t) and average evolutionary rate estimate ($\overline{r}$). Eq. 9 (top-left), Eq. 10 (top-right), Eq. 11 (bottom-left), and Eq. 12 (bottom-right) were fitted to 1,500 randomly-sampled sets of corresponding $\overline{r}$ and t estimates under the criterion of the least sum of squared errors of $\overline{r}$ (grey lines). The colours correspond to those of the node bars in Fig. 1a. The node numbers refer to those on the trees in Fig. 1a. The summary of the results can be found in Additional file 1: Table S3