Figure 3.

Selective sweeps when most effects are large: Dynamics of the scaled absolute mean deviation $\left|\Delta c_1\left(t\right)\right|/z_f$ (dotted, orange) and allele frequency (solid and dashed curves) for some loci that satisfy the necessary condition ${\gamma }_i<-2\Delta c_1\left(0\right),$ where $\Delta c_1\left(0\right)=-2.99$ and $z_f=3.$ The numerical solution of the full model (6) (solid) and directional selection model (10) (dashed) are shown for the effect size ${\gamma }_{i=1,\dots ,6}=0.776$ (gray), 0.340 (brown), 0.319 (red), 0.272 (magenta), 0.092 (blue), and 0.060 (black). The other parameters are $s=0.1,\hspace{0.17em}\mu ={10}^{-4},\hspace{0.17em}\overline{\gamma }=0.2,\text{and}\ell =20.$ Except for the locus with effect ${\gamma }_4,$ the allele frequency for the directional selection model exceeds one half at loci whose allele frequency for the full model sweeps. The allele frequency for the locus with effect ${\gamma }_6$ also increases nearly to fixation, but at very long times where the directional selection model is not valid. Because this frequency increase is relatively slow, a genomic signature similar to a selective sweep cannot be expected.