Fixation index

:或者1、简单介绍

固定指数(FST)是一种由遗传结构决定的种群分化指标。它通常是由遗传多态性数据，如单核苷酸多态性(SNP)或微卫星估计。作为莱特f统计的一个特例，它是种群遗传学中最常用的统计方法之一。

2、Definition

两个最常用的FST定义是基于群体间等位基因频率的方差，以及由血统决定身份的概率。

或者

p ¯ {\displaystyle {\bar {p}}} is the average frequency of an allele in the total population

p ¯ {\displaystyle {\bar {p}}} is the average frequency of an allele in the total population

^-p或者Π: is the average frequency of an allele in the total population

或者：variance in allele frequency among  populations(the variance in the frequency of the allele between different subpopulations, weighted by the sizes of the subpopulations)

或者Π(1-Π):the variance of the allelic state in the total population,

这种群体内部和群体之间遗传变异的比较常用于应用群体遗传学。取值范围从0到1。零值意味着完全的随机交配;也就是说，这两个种群可以自由交配。1的值意味着所有的遗传变异都由种群结构来解释，两个种群不具有任何遗传多样性。

p ¯ {\displaystyle {\bar {p}}} is the average frequency of an allele in the total population p ¯ {\displaystyle {\bar {p}}} is the average frequency of an allele in the total population