Characteristics of different types of loci. A) Derived frequency distributions. Derived allele frequencies are binned into 0.10 intervals and probability densities for different types of loci are indicated by shading (neutral expectations in light grey, HapMap SNPs in black, and disease-associated GWAS SNPs in dark grey). Similar numbers of loci were analyzed for each data type (1000 for neutral expectations and HapMap SNPs, and 1143 for GWAS SNPs). B) Estimated ages of SNPs. The probability density for HapMap SNPs (weighted by probability of detection) is labelled black and the probability density for disease-associated GWAS SNPs is labelled dark grey. Probability densities were obtained via Equation 12, and calculated at intervals of 0.04 Ne generations.