Table 2.

Mutational pattern in Drosophila non-coding DNA. Average fraction (±1 s.e.) of AT→GC and GC→AT polymorphisms and substitutions.

	polymorphic in D. melanogaster		fixed in D. melanogaster		fixed in D. simulans
	AT→GC	GC→AT	AT→GC	GC→AT	AT→GC	GC→AT
INs	0.0144±0.0009	0.0397±0.0020	0.0130±0.0009	0.0317±0.0021	0.0169±0.0010	0.0197±0.0014
IGs	0.0155±0.0011	0.0394±0.0024	0.0147±0.0012	0.0252±0.0020	0.0157±0.0010	0.0164±0.0015
all	0.0149±0.0007	0.0396±0.0015	0.0137±0.0007	0.0288±0.0015	0.0164±0.0007	0.0182±0.0010