Figure 5 .
Properties of the frequency spectrum under a spatially homogeneous model of sweeps using the coalescent process with rates given by Equation 17. Simulations were performed for a sample size of 20. For a particular x we adjusted the value of NνBP/(trBP) to achieve the specified reduction in π. (A and B) The percentage of segregating sites found at frequency 1 ≤ k ≤ 20, relative to the neutral expectation for sweeps. In each panel the reduction in diversity, π/θ is fixed. (C) The same quantities as in A and B, but for the case where there is no genetic drift, and sweeps are the only stochastic force affecting allele frequencies. (D) The fraction of segregating sites that are singletons, for different x, as a function of π/θ, calculated using recursions for [T1]/[Ttot] (Appendix B).