DoS/NI

DoS (Direction of Selection) = NI (Neutrality Index)

Measures the direction and degree of departure from neutral evolution.

The mean of DoS/NI values across genes is often taken to summarize patterns of selection in a species.

https://genesdev.cshlp.org/content/31/18/1841

DoS measures natural selection on recent time scales by contrasting nonsynonymous and synonymous polymorphisms (within species) to nonsynonymous and synonymous divergence (between species).

The DoS metric has an expected value of zero under neutrality, takes negative values under negative selection, and takes positive values under positive selection.

https://academic.oup.com/mbe/article/28/1/63/986360?login=true
https://academic.oup.com/mbe/article/25/10/2199/1031134?login=true

The McDonald–Kreitman (MK) test of selection compares the numbers of nonsilent (pN) and silent (pS) polymorphisms (within species) to the numbers of nonsilent (dN) and silent (dS) substitutions (between species) per locus.

pN/pS = nonsynonymous and synonymous polymorphisms (within species)
dN/dS = nonsynonymous and synonymous divergence (between species)

DoS (NI) = (pN/pS)/(dN/dS) = (pN*dS)/(pS*pN)

原文：

https://www.nature.com/articles/351652a0