deltaDAF calculation to search positive selection signals

Question

[seta]

Hi all,

As I found, deltaDAF betwen two populations is simply computed as DAFpop1 - DAFpop2; and also papers suggested various threshold of deltaDAF for signs of positive selection on SNP pass delatDAF threshold. As we have not any p-value, how we can say this difference is statistically significant, and move to next step (determine threshold and searching for positive selection)? Could you please share me your idea about this issue?

Thanks