Mean ML estimates for Δ obtained from simulated data. In all cases, the effective population size is Ne = 106. On the left, it is shown that the mean ML estimates of Δ are independent of the level of sequence coverage per site; 200 replicate runs were made per condition, with 105–106 independent pairs of sites sampled in each case. The horizontal lines denote the expected values given by Equation 6. On the right, for 10× coverage, it is shown that mean estimates of Δ are asymptotically unbiased with increasing numbers of sites; as on the left, varying combinations of the per-site parameters θ and ρ underlie the individual points.