Figure 5.

Estimated probabilities of neutrally evolving 500 kb ECHs

(A) Evenly spaced probabilities as the fraction of simulations in which a 500 kb haplotype along the chromosome rises to at least the specified frequency in 500,000 simulations. Each panel show simulations for the duration of the bottleneck, which increases from left (5,000 years) to right (25,000 years) in intervals of 5,000 years. Colors represent X chromosome population sizes listed in the legend, with the assumed autosomal population size and X/autosome ratio in parentheses. Crosses represent the upper bounds on the probability in each case where no haplotypes reached the target frequency in the simulation. A dashed horizontal line marks the 0.05 value. Vertical dotted lines represent the frequencies of the ECHs we identify in the SGDP male dataset.

(B) Same as (A) but represents the joint probability of the identified 500 kb ECHs below a given frequency. In each facet, the leftmost point thus represents the probability of observing only the lowest frequency ECH, and the rightmost point shows the joint probability of observing nineteen 500 kb ECHs at the frequency we identify.