Figure 2: Relation Between Information Entropy (H) Distributions in HA (A658) and HA(U658) Subsets. Observed H values (black circles) for nucleotide positions of subset A658 sequences are on the abscissa and for nucleotide positions of subset U658 sequences are on ordinate. H values for nucleotide positions of random subsets of the sequences are shown as red circles. The dotted red line is a reference straight line with slope = 1.0 and intercept = 0.0.