Log-likelihoods of a phylogenetic tree [6] of the concatenated sequences of 12 protein-coding sequences encoded on the same strand of mitochondrial DNA from 20 vertebrate species with 2 races from human.

aaIn all models named with a suffix "F", codon frequencies are taken to be equal to those in coding sequences. A suffix "dG4" means the discrete approximation of the distribution with 4 categories [44] for rate variation. The parameter in Eq. 11 is optimized in all models.
bThe number of parameters; the value for the mtREV-1-F is not quite correct, because mtREV was estimated from the almost same set of protein sequences [6].
cThe exchangeabilties of nonsynonymous and synonymous codon pairs are equal to multiplied by those of the corresponding amino acid pairs and all equal to the mean amino acid exchangeability in the empirical amino acid substitution matrix specified, respectively.
dKHGaa means the amino acid substitution matrix derived from KHG.
eAll parameters except and codon frequencies are fixed to those ML estimates of each model fitted to mtREV.