Sibly R M, Curnow R N
Department of Pure and Applied Zoology, University of Reading, U.K.
J Theor Biol. 1993 Feb 21;160(4):533-46. doi: 10.1006/jtbi.1993.1034.
For the case of weak selection, random assortment of gametes, and density-independent population regulation, we here establish the conditions under which an allele will spread in a population, with particular reference to the life-history effects of the allele, its level of dominance, and sex differences in its effects. Our treatment is simpler than that of Charlesworth (1980), but the results are essentially the same. We show that two quantities govern the selective dynamics of a two-allele single-locus system; these are level of dominance, and the difference between the per copy rates of increase of the alleles in homozygous populations. Our main conclusion is that the eventual outcome of evolution is unaffected by an allele's level of dominance, or sex differences in its effects, provided there is no overdominance. However, speed of progress to fixation is, of course, affected by these factors, and equations are derived to show how level of dominance affects speed of progress to fixation. When a dominant allele only affects the life history of one sex, its rate of spread is half that if both sexes are affected. The relationship between actual and intrinsic rates of increase is discussed and formulae are given showing the relationship for the case of weak selection.
对于弱选择、配子随机分配以及密度独立的种群调节情况，我们在此确定一个等位基因在种群中扩散的条件，特别提及该等位基因的生活史效应、其显性水平以及效应中的性别差异。我们的处理方法比查尔斯沃思（1980年）的更简单，但结果基本相同。我们表明有两个量决定双等位基因单基因座系统的选择动态；这两个量是显性水平以及等位基因在纯合种群中每拷贝增加率的差异。我们的主要结论是，进化的最终结果不受等位基因的显性水平或其效应中的性别差异影响，前提是不存在超显性。然而，固定进程的速度当然会受到这些因素的影响，并且推导了方程以表明显性水平如何影响固定进程的速度。当一个显性等位基因仅影响一个性别的生活史时，其扩散速率是两个性别都受影响时的一半。讨论了实际增长率与内在增长率之间的关系，并给出了公式以显示弱选择情况下的关系。
