A stochastic model of gene-culture coevolution suggested by the "culture historical hypothesis" for the evolution of adult lactose absorption in humans.

• DOI: 10.1073/pnas.83.9.2929
• Publication Date: 2006-05-31T07:48:05Z
• Authors: K Aoki
• Keywords: Coevolution; Trait

A stochastic model of gene-culture coevolution, suggested by the "culture historical hypothesis" Simoons and McCracken, is presented. According to this hypothesis, adult lactose absorption, believed be an autosomal dominant trait, attained a high frequency in some human populations due positive selection pressure induced culturally determined milk use those populations. Two-dimensional Kolmogorov backward equations with appropriate boundary conditions are derived for ultimate fixation probability users, gene both jointly, average time until gene. These value problems solved numerically Gauss-Seidel method. I define theoretical measure correlation between culture terms three probabilities. Monte Carlo simulations conducted check extend numerical results also obtain first arrival at 0.70, which approximately highest observed any population. Two that pertain hypothesis obtained. First, incomplete absorption does not necessarily constitute evidence against hypothesis. Second, postulated genetic change have occurred within 6000-year period since advent dairying, either effective population size was order 100, or, if it larger order, coefficient probably had exceed 5%.