Figure 2.

GC content of the third position of codons, short introns, and long introns for each recombination region. GC content at the third position of codons (GC3), short introns (≤80 base pairs [bp]) and long introns (>80 bp) for regions of high, intermediate and low frequency of crossing over and regions of no crossing over. Values reported are means per site for all introns from D. melanogaster and D. yakuba combined; error bars indicate 95% confidence interval (CI) obtained by bootstrapping by gene/intron.