Fig. 3.

Value of α as a function of τ and other parameters in forward simulations. We report best-fit α estimates for simulations at each value of τ at a given genome-wide average selection coefficient $\overline{s}$. Selection coefficients were sampled using a gamma distribution shape parameter of k = 0.25 (solid lines) or k = 0.125 (dotted lines). α estimates where calculated by fitting the model in Eq. (1) to simulated SNP effects above twice the MAF threshold $2T=\frac{k}{2N_e\overline{s}}$ (in order to avoid edge effects near T), with error bars representing standard errors calculated by bootstrap resampling of 25 independent SLiM2 simulations. The horizontal dashed line indicates α = −0.38, the best-fit α across the 25 UK Biobank traits. Results for a broader range of k values are reported in Supplementary Figure 5. Source data are provided as a Source Data file