Fig. 2
Positive selection analysis on mitochondrial genes on each branch (arbitrary labels, b1-b24, appear above each branch). The number below each branch represents the number of positively selected sites with posterior probability higher than 0.8. The number in parentheses is the product of proportion of sites having ω > 1 and ω 2 for that branch, as an indicator of the strength of positive selection. The width of the branches is proportional to the strength of positive selection (because ω 2 for b12 and b24 is extremely high, the width was capped for ease of visualization). Labled branches without values listed have no evidence of positive selection