Fst

F_st is a measure of population divergence. It measures the reduction in heterozygosity in a subdivided population compared to that in large, random mating population with the same allele frequencies.

References

Nielsen R, Mountain JL, Huelsenbeck JP, Slatkin M (1998) Maximum-Likelihood Estimation of Population Divergence Times and Population Phylogeny in Models Without Mutation. Evolution 52:669-677