Comparisons between various codon substitution models in the concatenating analysis of mammalian-mtDNA.

aThe prior probability of each category for the “dG4s” is , and .
bThe number of adjustable parameters.
cDifferences from the reference state; , , and .
dThe average of over all amino acid pairs ; .
eThe value parenthesized means that the parameter is fixed at the value specified.
fThe scale parameter of a distribution for the variation of mutation rate over time.
gThe ratio of double to single and of triple to double nucleotide change exchangeability; .
hThe ratio of mean transitional to mean transversional exchangeability; .
iThe shape parameter of a discrete gamma distribution for the variation of mutation rate or selective constraint over sites.