Fig. 2.

Distribution of the number of segregating sites and Tajima D values in each set of 1,000 simulations. The gray line in the top panel corresponds to the expected number of segregating sites under the standard neutral model: $\pi \text{=}\theta \text{.}L\text{.}{a}_n$ where $a_n=\sum _1^{n-1}\frac{1}{i}$. Here, $\theta =0.02$, $L=\mathrm{20,000}$, and $n=100$. The gray line in the bottom panel corresponds to the expected Tajima D under the neutral model (D = 0).