Figure 1.

Estimates of $s_{\text{a}}^2$ and $s_{\text{c}}^2$ for mammals (blue), primates (green) and carnivores (red). Kernel densities show the distributions of MCMC samples of $s_{\text{a}}^2$ when $s_{\text{c}}^2=0$. Joint estimates of $s_{\text{a}}^2$ and $s_{\text{c}}^2$ are indicated by dots, the error bars of which enclose 95% of MCMC samples.