Charlesworth B
Department of Ecology and Evolution, University of Chicago.
Mol Biol Evol. 1998 May;15(5):538-43. doi: 10.1093/oxfordjournals.molbev.a025953.
Wright's FST and related statistics are often used to measure the extent of divergence among populations of the same species relative to the net genetic diversity within the species. This paper compares several definitions of FST which are relevant to DNA sequence data, and shows that these must be used with care when estimating migration parameters. It is also pointed out that FST is strongly influenced by the level of within-population diversity. In situations where factors such as selection on closely linked sites are expected to have stronger effects on within-population diversity at some loci than at others, differences among loci can result entirely from differences in within-population diversities. It is shown that several published cases of differences in FST among regions of high and low recombination in Drosophila may be caused in this way. For the purpose of comparisons of levels of between-population differences among loci or species which are subject to different intensities of forces that reduce variability within local populations, absolute measures of divergence between populations should be used in preference to relative measures such as FST.
赖特的固定系数（FST）及相关统计量常被用于衡量同一物种不同种群间的分化程度相对于该物种内净遗传多样性的情况。本文比较了与DNA序列数据相关的几种FST定义，并表明在估计迁移参数时必须谨慎使用这些定义。还指出FST受种群内多样性水平的强烈影响。在某些情况下，如对紧密连锁位点的选择等因素对某些位点的种群内多样性的影响预计比对其他位点更强，位点间的差异可能完全源于种群内多样性的差异。结果表明，果蝇中高重组区和低重组区之间FST差异的几个已发表案例可能就是由此造成的。为了比较受降低局部种群内变异性的不同强度作用力影响的位点或物种间种群间差异水平，应优先使用种群间分化的绝对度量，而非诸如FST这样的相对度量。
