I understand that HKA test tests for neutrality. And under neutrality we say that "ratio of segregating sites with species (S1) and fixed differences between locus (F1)" (S1/F2) at one locus is equal to S2/F2 of another locus.
But what will S1/F1 > S2/F2 signify? And what will S1/F1 < S2/F2 mean?