Fig. 2.

Comparison of nucleotide changes introduced by recombination and mutation. Cumulative proportions of SNPs at 4-fold degenerate sites (GC4) for each of the six types of nucleotide changes, as calculated for all alleles introduced by recombination new alleles introduced by recombination all alleles introduced by mutations new alleles introduced by mutations. Values were normalized by the GC-contents at 4-fold degenerate sites for each species prior to calculating overall proportions, and species with fewer than 50 polymorphic sites for a given category of alleles were excluded.