Figure 4.
Compositional nonequilibrium in the nonrepetitive noncoding regions of the primate genome. The difference between the number of GC→AT substitutions and the number of AT→GC substitutions (expected to be zero at equilibrium) is plotted against G+C content. Data points represent nonoverlapping 5-kb blocks of intronic and intergenic sequence, with human and chimpanzee lineage-specific substitutions summed. The line gives the linear regression, indicating the bias at high GC.
