Structural differences between human and chimpanzee sequences. (A) Diversity profile of nucleotide differences between the human and chimpanzee genomic sequences using a sliding window of 1,000 bp across the entire 1.68-Mb aligned genomic sequence, including single-nucleotide indels. The aligned sequence is shown along the horizontal axis, and the percent nucleotide differences calculated per 1 kb of nonoverlapping windows are shown along the vertical axis. Diversity profiles of a single-nucleotide indel and substitutions by transition and transversion are indicated by blue, pink, and yellow lines, respectively. The relative positions of the MHC class I (multicopy) gene (brown) and non-MHC (single copy) gene (light blue) regions are shown along the horizontal axis. (B) Alteration of percentages of continuous indels that override 2-bp length.