PHENOTYPIC EVOLUTION BY NEUTRAL MUTATION
PHENOTYPIC EVOLUTION BY NEUTRAL MUTATION
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DOI：
10.1111/j.1558-5646.1986.tb00561.x
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发表时间：
1986-09-01
期刊：
影响因子：
3.3
通讯作者：
HILL, WG
中科院分区：
文献类型：
--
作者：
LYNCH, M;HILL, WG
在随机抽样漂移和突变的联合作用下，建立了一个预测群体内遗传方差和群体平均数量性状表型发散率的通用模型。除了包含突变等位基因的显性效应外，该模型还深入了解了连锁和交配系统对数量遗传变异的突变生产的影响。尽管有这些额外的和潜在的严重并发症，但研究发现，对于较小的人群，以前的研究人员使用加性遗传模型获得的简单预测相当好地适用。即使在考虑显性和连锁后，遗传方差的平衡水平也不太可能远小于2NVm或大于4NVm，其中N是有效种群规模，Vm是每一代出现的突变所产生的新方差。尽管达到渐近速率的时间与N成正比，但每代行间方差的增长速度最终等于2Vm，尽管达到渐近速率的时间与N成正比。给出了接近遗传方差平衡水平的速度以及种群内和种群间遗传方差的预期方差的表达式。在检测自然选择、保持用于生物医学和农业目的的纯系、开发遗传保护计划以及设计物种间形态距离指数的背景下，讨论了衍生模型的相关性，该模型相当于中性理论到表型水平的推广。
A general model is developed for predicting the genetic variance within populations and the rate of divergence of population mean phenotypes for quantitative traits under the joint operation of random sampling drift and mutation in the absence of selection. In addition to incorporating the dominance effects of mutant alleles, the model yields some insight into the effects of linkage and the mating system on the mutational production of quantitative-genetic variation. Despite these additional and potentially serious complications, it is found that, for small populations, the simple predictions obtained by previous investigators using additive-genetic models hold reasonably well. Even after accounting for dominance and linkage, the equilibrium level of genetic variance is unlikely to be much less than 2NVm or to be more than 4NVm, where N is the effective population size and Vm is the new variance from mutation appearing each generation. The rate of increase of the between-line variance per generation ultimately equals 2Vm regardless of population size, although the time to attain the asymptotic rate is proportional to N. Expressions are presented for the rate of approach to the equilibrium level of genetic variance and for the expected variance of the within-population and between-population genetic variances. The relevance of the derived model, which amounts to a generalization of the neutral theory to the phenotypic level, is discussed in the context of the detection of natural selection, the maintenance of pure lines for biomedical and agricultural purposes, the development of genetic conservation programs, and the design of indices of morphological distance between species.