Fig. 6

Molecular distance distributions of P. tepidariorum paralogs and speciation nodes. The distribution of mean HKY distances from P. tepidariorum duplication nodes to P. tepidariorum descendants reveals three distributions shown in different colors in (a). Comparing the distribution of HKY distances from speciation nodes to P. tepidariorum (lines in b) reveals that distribution #1 (red in a) is restricted to the P. tepidariorum branch, distribution #2 (green in a) is similar to pre-spider and post-tick speciation nodes, and distribution #3 (blue in a) is older than the P. tepidariorum-tick speciation event. N = number of speciation nodes in (b). Comparing the number of duplication nodes in non-P. tepidariorum species (c) that are either partially or fully retained in P. tepidariorum reveals that the duplication nodes with HYK distances in the range of the oldest P. tepidariorum distribution (blue in a) are retained at a similar rate across all species (right sub-columns in c), but that those duplication nodes with HKY distances in the range of the middle P. tepidariorum distribution (green in a) are only retained in scorpions or more closely related species (left sub-columns in c)