Fig. 3.

Population ancestry appears to have not shifted appreciably between time points. African versus European ancestry was estimated along chromosomes using the hidden Markov model of Corbett-Detig and Nielsen (2017). African ancestry proportion was averaged across inversion-free strains in the original samples (black line), averaged across six pools in the fall sample (blue), and 12 pools in the spring sample (yellow). Because inversions can affect ancestry, and we observed shifts in inversions frequencies between time points, we weighted ancestry in the old samples to match inversion frequencies between the time points. This weighted ancestry along the genome is shown here.