Table 3.

Proportions of nucleotide differences at 4-fold, FEI sites and first introns. Standard errors are shown in parentheses

Sites	Type of nucleotide change
	A↔C	C↔G	A↔G	T↔C	A↔T	T↔G
4-fold sites	0.0132 (0.0015)	0.0155 (0.0017)	0.0283 (0.0024)	0.0211 (0.0021)	0.0126 (0.0017)	0.0130 (0.0017)
FEI	0.0187 (0.0020)	0.0193 (0.0025)	0.0384 (0.0029)	0.0355 (0.0025)	0.0200 (0.0018)	0.0178 (0.0018)
First intron	0.0092 (0.0014)	0.0127 (0.0018)	0.0196 (0.0021)	0.0233 (0.0021)	0.0098 (0.0013)	0.0094 (0.0014)