Fig. 2
From: Ruminant-specific multiple duplication events of PRDM9 before speciation
The rate of nonsynonymous (dN) to synonymous (dS) substitutions (ω =;dN/dS) of different branches. The analysis was based on the N-terminal portion of the coding nucleotide sequences of PRDM9. The free-ratio model (M1), which assumes independent ω for each branch, is the best-fit model (p =;0.1) over the one-ratio model (M0) that assumes uniform ω for all the branches in the phylogeny. ω >1 are in bold