Figure 4From: Codon usage in vertebrates is associated with a low risk of acquiring nonsense mutationsCpG content of all CDS in 40 species relative to F. Symbols are identical to Figure 3: protozoa (△), plants (□), fungi (○), invertebrates (▲), and vertebrates (●). The CDS in a species with an unbiased codon usage has an F = 1.0 (horizontal dotted line). All vertebrates have a CpG content < 0.04 (vertical dotted line).Back to article page