Background selection and ILS.

<p>The plots show the ratio of ILS inside the low ILS regions compared to that outside the regions, assuming speciation times of 5.95 mya and 3.7 mya, 20 year generations and that the neutral X effective population size is three quarters that of the autosomes. The colors correspond to different choices of which fraction of mutations are deleterious, varying from 1% to 10%. The different columns correspond to different choices of selection within the low ILS regions—set to either the same as outside or one tenth of the selection strength outside—and different rows show how much more of the regions is under selection compared to outside, either the same or a factor of five or ten. Selection strength is set to either 1e-4 (dotted curve) or 1e-5 (solid curve). The horizontal dashed line represents the observed reduction in ILS of 24% (from 21% ILS outside low-ILS regions to the <5% ILS of low-ILS regions).