Population Branch Statistic (PBS

PBS (population branch statistic)

A population’s PBS value represents the amount of allele frequency change at a given locus in the history of this population (since its divergence from the other two populations). 

This approach is similar to the “locus-specific branch lengths” statistic used by Shriver et al. (S7), except that by using the above log-transformation, we obtain additive distances that place branches of different magnitudes on the same scale. 

This statistic should be very powerful to detect selection. It should have power, for example to detect incomplete selective sweeps, a type of selection that is highly relevant here and which most other statistics based on the SFS have little power to detect.

PBS 表示某种群历史中，某一特定位点的等位基因频率变化量，可以理解为特定位点的分支距离，常用于检测近期的自然选择。