Fig. 4

Selection signature at regulatory SNPs of representative genes. The mean pairwise differences between allelic classes (dark red) and within an allelic class (light red) for the regulatory sequences with Tajima’s D > 1.5 and whose patterns of noise in chromatin variability and associated gene expression are shown in Fig. 3e, f (green dots). The pairwise differences were calculated in 500-bp sliding windows. The pairwise differences between haplogroups compared with those within haplogroups are plotted. The between-group (dark blue) and within-group (light blue) pairwise differences near the HLA-B and HLA-DRB1 SNPs in chimpanzees are shown on the right-hand y-axis