A STOCHASTIC-MODEL OF GENE CULTURE COEVOLUTION SUGGESTED BY THE CULTURE HISTORICAL HYPOTHESIS FOR THE EVOLUTION OF ADULT LACTOSE ABSORPTION IN HUMANS
A STOCHASTIC-MODEL OF GENE CULTURE COEVOLUTION SUGGESTED BY THE CULTURE HISTORICAL HYPOTHESIS FOR THE EVOLUTION OF ADULT LACTOSE ABSORPTION IN HUMANS
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DOI：
10.1073/pnas.83.9.2929
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发表时间：
1986-05-01
影响因子：
11.1
通讯作者：
AOKI, K
中科院分区：
文献类型：
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作者：
AOKI, K
本文提出了一个由Simoons和麦克拉肯的“文化历史假说”提出的基因-文化协同进化的随机模型。根据这一假设，成人乳糖吸收，被认为是一种常染色体显性性状，在一些人群中达到了高频率，这是由于在这些人群中由文化决定的牛奶使用诱导的正选择压力。二维Kolmogorov向后方程与适当的边界条件推导出最终的固定概率的牛奶用户，成人乳糖吸收的基因，两者联合，并为平均时间，直到固定的基因。这些边值问题用Gauss-Seidel方法数值求解。我定义了一个理论上衡量基因和文化之间的相关性的三个最终的固定概率。蒙特卡洛模拟进行检查和扩展的数值结果，并获得在基因频率0.70，这是大约在任何人口中观察到的最高频率的第一个到达时间。得到了两个与文化历史假说相符合的结果。首先，在成人乳糖吸收和牛奶使用之间观察到的不完全相关性并不一定构成反对该假设的证据。第二，假设的遗传变化发生在6000年的时间内，因为乳品业的出现，要么有效的人口规模是100的顺序，或者，如果它是更大的顺序，选择系数可能必须超过5%。
A stochastic model of gene-culture coevolution, suggested by the "culture historical hypothesis" of Simoons and McCracken, is presented. According to this hypothesis, adult lactos absorption, believed to be an autosomal dominant trait, attained a high frequency in some human populations due to the positive selection pressure induced by culturally determined milk use in those populations. Two-dimensional Kolmogorov backward equations with appropriate boundary conditions are derived for the ultimate fixation probability of milk users, of the gene for adult lactose absorption, and of both jointly, and for the average time until fixation of the gene. These boundary value problems are solved numerically by the Gauss-Seidel method. I define a theoretical measure of the correlation between gene and culture in terms of the three ultimate fixation probabilities. Monte Carlo simulations are conducted to check and extend the numerical results and also to obtain the first arrival time at gene frequency 0.70, which is approximately the highest observed frequency in any population. Two results that pertain to the culture historical hypothesis are obtained. First, the incomplete correlation observed between adult lactose absorption and milk use does not necessarily constitute evidence against the hypothesis. Second, for the postulated genetic change to have occurred within the 6000-year period since the advent of dairying, either the effective population size was of the order of 100, or, if it was of larger order, the selection coefficient probably had to exceed 5%.