Campbell R B
Department of Mathematics and Computer Science, University of Northern Iowa, Cedar Falls 50614-0441.
J Hered. 1988 May-Jun;79(3):179-83. doi: 10.1093/oxfordjournals.jhered.a110489.
Mating structure governs the distribution of alleles in populations and thus the extent to which the phenotypes associated with the alleles are manifested. A mating system which initially achieves more genetic identity within individuals than between individuals enhances the probability that a finite population without reproductive excess will become extinct from a recessive lethal or semidominant lethal mutation; however, such a mating system decreases the number of deaths that will ensue if the population size is maintained by replacement of inviable progeny with individuals engendered from the entire mating pool. This is illustrated with Markov chain models for half-sib and double-first-cousin mating in populations of four individuals and by various techniques for analogous large populations. An appropriate choice of mating strategy can mitigate the effect of deleterious mutations, but the determination of which strategy is appropriate depends on how much reproductive excess is available and on the relative costs assigned to individual deaths and the extinction of a population.
交配结构决定了种群中等位基因的分布，进而决定了与这些等位基因相关的表型得以显现的程度。一种最初在个体内部而非个体之间实现更多基因同一性的交配系统，会增加一个没有生殖过剩的有限种群因隐性致死或半显性致死突变而灭绝的可能性；然而，如果通过用整个交配群体产生的个体替代不可存活的后代来维持种群数量，那么这种交配系统会减少随之而来的死亡数量。这通过四个个体的种群中半同胞和双重亲表兄妹交配的马尔可夫链模型以及各种适用于类似大种群的技术得到了说明。交配策略的适当选择可以减轻有害突变的影响，但确定哪种策略合适取决于有多少生殖过剩可用，以及分配给个体死亡和种群灭绝的相对成本。
