Figure 5. HIV-1 subtype D has the most divergent sequence.

Boxplots show the median and dispersion of the nucleotide divergence of individual HIV-1 genomes from different subtypes to the average of human coding sequences. Red stars indicate that D subtype is significantly more divergent than other subtypes (p = 2×10⁻⁶ ANOVA test, p = 5.8×10⁻⁶ Student t-test, p = 2.8×10⁻⁷ Wilcoxon test). The random 10 kb column shows the median and standard deviation of the divergence between 10 kb of random human coding sequences and the average of all human coding sequences; 95% of the points have a divergence below 0.03, and less than 1% of the points are above 0.05, ie comparable to HIV divergence. Standard deviation gives a natural scale of variation to the graph. These data were not used in the statistical procedure to compare subtypes.