Fig. 2. Heterogeneous sequence divergence within datasets including only the first, the second, the third codon positions or all codon positions. The obtained mean similarity score between sequences was represented by a colored square. The scores were ranging from 1, indicating full random similarity, to +1, non-random similarity. The darker red indicated the higher randomized similarities between pairwise sequence comparisons. Blue indicated the opposite. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)