A Tutorial of F-Statistics for Genome-wide Analysis of Population Differentiation

A characteristic of many wild and domesticated plant/animal species with continuous distribution ranges over broad geographic regions is that individual species consist of numerous populations, each of which is adapted to only a portion of the environmental conditions across the species’ entire range. Indirect evidence for such continuous variation among populations is the occurrence of small changes in allele frequencies across the environmental gradients as often revealed by molecular surveys of population differentiation. Wright’s F-statistics or its refinements are routinely used for assessment of population differentiation. In this presentation, we will first provide a brief overview on traditional uses of F-statistics and will then focus on exploring some of its new uses for genome-wide assessment of population differentiation. These new uses of F-statistics will be illustrated with the analysis of a genomic data set from the Arabidopsis thaliana polymorphism database (AtPolyDB).