Nagylaki T
Department of Ecology and Evolution, University of Chicago, Illinois 60637, USA.
Genetics. 1997 Feb;145(2):485-91. doi: 10.1093/genetics/145.2.485.
Three different derivations of models with multinomial sampling of genotypes in a finite population are presented. The three derivations correspond to the operation of random drift through population regulation, conditioning on the total number of progeny, and culling, respectively. Generations are discrete and nonoverlapping; the diploid population mates at random. Each derivation applies to a single multiallelic locus in a monoecious or dioecious population; in the latter case, the locus may be autosomal or X-linked. Mutation and viability selection are arbitrary; there are no fertility differences. In a monoecious population, the model yields the Wright-Fisher model (i.e., multinomial sampling of genes) if and only if the viabilities are multiplicative. In a dioecious population, the analogous reduction does not occur even for pure random drift. Thus, multinomial sampling of genotypes generally does not lead to multinomial sampling of genes. Although the Wright-Fisher model probably lacks a sound biological basis and may be inaccurate for small populations, it is usually (perhaps always) a good approximation for genotypic multinomial sampling in large populations.
本文提出了有限群体中基因型多项抽样模型的三种不同推导方法。这三种推导方法分别对应于通过种群调节的随机漂移操作、以后代总数为条件以及淘汰。世代是离散且不重叠的；二倍体群体随机交配。每种推导方法适用于雌雄同体或雌雄异体群体中的单个多等位基因座；在后一种情况下，该基因座可以是常染色体或X连锁的。突变和生存力选择是任意的；不存在育性差异。在雌雄同体群体中，当且仅当生存力是可乘性时，该模型才产生赖特-费希尔模型（即基因的多项抽样）。在雌雄异体群体中，即使对于纯随机漂移，类似的简化也不会发生。因此，基因型的多项抽样通常不会导致基因的多项抽样。尽管赖特-费希尔模型可能缺乏可靠的生物学基础，并且对于小群体可能不准确，但它通常（也许总是）是大群体中基因型多项抽样的一个良好近似。
