Gillespie J, Langley C
Genetics. 1976 Jan;82(1):123-37. doi: 10.1093/genetics/82.1.123.
In this paper the consequences of natural selection acting on several loci simultaneously in a spatially fluctuating environment are described. The fitnesses of the genotypes are assumed to be additive both within and between loci. The environment is assumed to be made up of a very large (effectively infinite) number of patches in which fitnesses are assigned at random. The resulting deterministic model is called a Random Levene Model and its properties are approximate by a system of differential equations. The main equilibrium properites are that (1) the linkage disequilibrium is zero and (2) the correlations in fitness between alleles at different loci are the principle determinants of the dynamic inter-locus interactions. Although there is no epistasis as conventionally defined, the equilibrium state at the two loci are highly interdependent, the governing principle being that two alleles at different loci whose fitness are negatively correlated across environments have a higher overall fitness due to the reduction in their variance in fitness through the negative correlation. When a large number of loci are considered, they naturally fall into correlation groupings which lead to an enhanced likelihood for polymorphism over that predicted by single-locus theory.
本文描述了在空间波动环境中自然选择同时作用于多个基因座的后果。假设基因型的适应度在基因座内部和之间都是可加的。假设环境由非常大量（实际上是无限）的斑块组成，其中适应度是随机分配的。由此产生的确定性模型称为随机莱文模型，其性质由一个微分方程组近似。主要的平衡性质是：（1）连锁不平衡为零；（2）不同基因座上等位基因之间的适应度相关性是动态基因座间相互作用的主要决定因素。尽管不存在传统定义的上位性，但两个基因座的平衡状态高度相互依赖，其主导原则是，在不同环境中适应度呈负相关的不同基因座上的两个等位基因，由于通过负相关降低了它们适应度的方差，因而具有更高的总体适应度。当考虑大量基因座时，它们自然会形成相关性分组，这导致多态性出现的可能性比单基因座理论预测的更高。
