Figure 3From: The erratic mitochondrial clock: variations of mutation rate, not population size, affect mtDNA diversity across birds and mammalsDistribution of cytochrome b neutral substitution rate in 1,696 mammalian species (Data from [14]) and 1,571 birds species (this study). Substitution rates are in unit of substitution per third codon position per million years. Values above 0.4 substitution/site/Myrs years are not shown.Back to article page