Statistical Measures for Genetic Differentiation: Review

A primary goal of empirical population genetic studies is the identification, quantification and comparison of genetic differentiation among loci, individuals, populations, species and studies. Determining the genetic structure of natural populations forms an important part of population genetics and has many applications in evolutionary biology, conservation, forensics and plant and animal breeding. Population differentiation is a fundamental process of evolution, and many evolutionary studies, such as population genetics, phylogeography and conservation biology, all require the inference of population differentiation. Estimates of the fixation index have been used as measures of population differentiation for many decades. The method most frequently used to assess population structure is the calculation of
, a summary statistic first introduced by Wright. Fixation measurements of the genetic differentiation among subpopulations are fundamental parameters in population genetics, with many valuable applications in molecular biology, evolutionary biology, conservation and forensic. A number of related indices of genetic differentiation have been subsequently derived in link with the natures of the diagnostic genetic markers such as GST, ΦST, RST. This paper is intended to be a review of the genetic differentiation indices that population geneticists frequently use. For this purpose seven fixation indices were investigated. In the literature, different indices are commonly used to quantify population differentiation, and none of them can be considered beter than others in all respects.