Spielman R S, Neel J V, Li F H
Genetics. 1977 Feb;85(2):355-71. doi: 10.1093/genetics/85.2.355.
Four different estimation procedures for models of population structure are compared. The parameters of the models are shown to be equivalent and, in most cases, easily expressed in terms of the parameters WRIGHT calls "F-statistics." We have estimated the parameters of each of these models with data on nine codominant allele pairs in 47 Yanomama villages, and we find that the different estimators for a given parameter all yield more or less equivalent results. F-statistics are often equated to inbreeding coefficients that are definid as the probability of identity by descent from alleles taken to be unique in some founding population. However, we are led to infer from computer simulation and general historical considerations that all estimates from genotype frequencies greatly underestimate the inbreeding coefficient for alleles in the founding population of American Indians in the western hemisphere. We surmise that in the highly subdivided tribal populations which prevailed until the recent advent of civilization, the probability of identity by descent for homologous alleles was roughly 0.5. We consider some consequences of working with the customary, much lower, estimates--0.005 to 0.01--if, on the time scale of human evolution, these represent only a very recent departure from the inbreeding intensity that prevailed before civilization.
我们比较了四种不同的群体结构模型估计方法。结果表明，这些模型的参数是等效的，并且在大多数情况下，可以很容易地用赖特所称的“F统计量”参数来表示。我们利用47个雅诺马马村庄中9个共显性等位基因对的数据，估计了上述每个模型的参数，发现给定参数的不同估计量都给出了大致等效的结果。F统计量通常等同于近亲繁殖系数，近亲繁殖系数的定义是，在某个奠基群体中，等位基因通过系谱遗传而相同的概率，这些等位基因在奠基群体中被视为是独一无二的。然而，通过计算机模拟和一般历史考量，我们推断，根据基因型频率得出的所有估计值都大大低估了西半球美洲印第安人奠基群体中等位基因的近亲繁殖系数。我们推测，在直到最近文明出现之前普遍存在的高度细分的部落群体中，同源等位基因通过系谱遗传而相同的概率约为0.5。我们考虑了使用习惯上低得多的估计值（0.005至0.01）的一些后果，因为如果从人类进化的时间尺度来看，这些估计值仅代表最近才偏离文明出现之前普遍存在的近亲繁殖强度。
