Charlesworth B
Department of Ecology and Evolution, University of Chicago, IL 60637.
J Hered. 1993 Sep-Oct;84(5):345-50. doi: 10.1093/oxfordjournals.jhered.a111355.
Theoretical models of the evolutionary advantages of sex and genetic recombination in a temporally varying environment are analyzed. The models assume a quantitative trait controlled by many additive genes and subject to nor-optimal selection. The optimal value of the trait is assumed either to move steadily in one direction or to follow an autocorrelated linear Markov process. The consequences for population mean fitness of a reduction in genetic variance, due to a shift from sexual to asexual reproduction, are examined. It is shown that a large reduction in mean fitness can result from such a shift in the case of a steadily moving optimum, under light conditions. The conditions are much more stringent with a randomly varying environment, especially if the autocorrelation is low. The conditions for spread of a rare modifier affecting the rate of genetic recombination are also examined, and the strength of selection on such a modifier is determined. Again, the case of a steadily moving optimum is more favorable than a random optimum for the evolution of increased recombination.
分析了在随时间变化的环境中，性别和基因重组进化优势的理论模型。这些模型假设一个由许多加性基因控制的数量性状，并受到非最优选择。假设该性状的最优值要么在一个方向上稳定移动，要么遵循自相关线性马尔可夫过程。研究了由于从有性繁殖转变为无性繁殖导致遗传方差减少对种群平均适合度的影响。结果表明，在稳定移动的最优值情况下，在轻度条件下，这种转变可能导致平均适合度大幅降低。在随机变化的环境中，条件要严格得多，尤其是自相关性较低时。还研究了影响基因重组率的稀有修饰因子传播的条件，并确定了对这种修饰因子的选择强度。同样，对于增加重组的进化而言，稳定移动的最优值情况比随机最优值情况更有利。
