GST and its relatives do not measure differentiation
GST and its relatives do not measure differentiation
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DOI：
10.1111/j.1365-294x.2008.03887.x
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发表时间：
2008-09-01
影响因子：
4.9
通讯作者：
Jost, Lou
中科院分区：
文献类型：
--
作者：
Jost, Lou
G（ST）及其近亲通常被解释为亚种群之间分化的度量，值接近零被认为表示低分化。然而，当基因多样性高时，即使亚群体完全分化，G（ST）也必然趋近于零，并且随着分化的增加，G（ST）也不是单调的。同样，当多样性等同于杂合性时，即使亚种群完全不同（没有共享等位基因），当多样性高时，采用亚种群内平均多样性与总多样性之比形成的标准相似性度量也必然趋于一致。这些措施都不能被解释为区分或相似的措施。这些措施的推导包含两个微妙的误解，导致其矛盾的行为。基于这些固定指数或相似性测量，关于种群分化、基因流、亲缘性和保护优先级的结论往往是错误的。这些不是统计问题；即使在计算中使用了真实的人口频率，问题仍然存在。多样性数学的最新进展确定了这些误解，并产生了数学上一致的种群结构描述性度量，消除了标准度量产生的悖论。这些措施可以直接关系到有限岛模型的迁移率和突变率。
G(ST) and its relatives are often interpreted as measures of differentiation between subpopulations, with values near zero supposedly indicating low differentiation. However, G(ST) necessarily approaches zero when gene diversity is high, even if subpopulations are completely differentiated, and it is not monotonic with increasing differentiation. Likewise, when diversity is equated with heterozygosity, standard similarity measures formed by taking the ratio of mean within-subpopulation diversity to total diversity necessarily approach unity when diversity is high, even if the subpopulations are completely dissimilar (no shared alleles). None of these measures can be interpreted as measures of differentiation or similarity. The derivations of these measures contain two subtle misconceptions which cause their paradoxical behaviours. Conclusions about population differentiation, gene flow, relatedness, and conservation priority will often be wrong when based on these fixation indices or similarity measures. These are not statistical issues; the problems persist even when true population frequencies are used in the calculations. Recent advances in the mathematics of diversity identify the misconceptions, and yield mathematically consistent descriptive measures of population structure which eliminate the paradoxes produced by standard measures. These measures can be directly related to the migration and mutation rates of the finite-island model.