Population differentiation: Measures

Abstract

The genetic divergence between populations or accumu- lated by a single population from an ancestral group can be quantified using different measures. None of them can be considered better than others in all respects. The type of marker(s) or gene(s) analysed, the temporal scale considered and the level of variation are differentially affecting the quality of an index, and standardisation for comparisons across groups of populations or species is important. Some commonly used measures of population differentiation are briefly discussed, and it is argued that these measures or related quantities can be used to esti- mate crucial evolutionary and demographic parameters such as divergence times and migration rates, and to identify genes affected by natural or artificial selection processe