Table 1.
Symbols used in this paper
| Symbol | Description |
|---|---|
| S | Number of synonymous sites |
| N | Number of nonsynonymous sites |
| Ks | Synonymous substitution rate |
| Ka | Nonsynonymous substitution rate |
| ω | Estimator of selective pressure, ω=Ka/Ks |
| Sd | Number of synonymous substitutions |
| Nd | Number of nonsynonymous substitutions |
| t | Divergence time between two sequences |
| a | The shape parameter of gamma distribution |
| α | Transitional rate |
| α1 | Transitional rate between purines |
| α2 | Transitional rate between pyrimidines |
| β | Transversional rate |
| κ | Ratio of transitional rate/transversional rate |
| κR | Ratio of transitional rate between purines to transversional rate, κR=α1/β |
| κY | Ratio of transitional rate between pyrimidines to transversional rate, κY=α2/β |
| gN | Frequency of nucleotide N, N∈[T, C, A, G] |
| gR | gR = gA + gG |
| gY | gY = gT + gC |