The median number of SNVs per gene was 24, ranged between 0 and 761, and was significantly different (Wilcoxon-rank sum test; P < 10−15) between AAs (median of 16, range from 0 to 566) and EAs (median of 13, range from 0 to 410). Mutational target size plays an important role in governing differences in polymorphism across loci, because gene length accounts for 76.6% of variation in the number of SNVs across genes (95% bootstrap CI = 73.9 to 79.1%; P < 10−15).
