TABLE 3

Substituted positions in codons with one synonymous and one nonsynonymous substitution between D. subobscura and D. pseudoobscura

Codon positions of the substitutionsObservedExpected ratioa
1,250.037
1,3440.478
2,3420.485
GWilliams = 0.793, P = 0.673
• a Expected ratio based on the frequency of synonymous substitutions at the different codon positions in a random coding sequence: 0.046, 0.0, and 0.598, for the first, second, and third codon positions, respectively.