Fig. 4.

Estimated nucleotide diversity (∏) of all exons for the different MHC loci A, B, C, and A-like DNA sequences from 20 unrelated bonobos and central chimpanzees reported here and 20 western chimpanzees and 20 humans (Yoruba) from the literature (Adams et al. 2000; The International HapMap C 2005). Error bars represent the standard error of the mean. Significant differences are indicated by stars above the individual bars, whereby small stars indicate significant differences between two bars linked by a line and big stars indicate significant differences to every other bar at this particular locus (permutation test, 10,000 resamplings, Bonferroni correction, p ≤ 0.002)