Table 1.

GC vs. AT bias for polymorphisms and human lineage substitutions

	AT to GC	GC to AT	Neither
Polymorphisms	0.105 (2)	0.684 (13)	0.211 (4)
Substitutions	0.841 (37)	0.091 (4)	0.068 (3)

These data were taken from a 5.5 kb region around element 2. Counts are in parentheses. Cases where the mutation was at a hypermutable CG dinucleotide were ommited.