Campbell R B
Department of Mathematics, University of Northern Iowa, Cedar Falls 50614, USA.
J Theor Biol. 1995 Aug 21;175(4):503-9. doi: 10.1006/jtbi.1995.0157.
Heterozygosity and the number of alleles are both measures of the genetic variation of a population. They are qualitatively similar if the distribution of the number of progeny is Poisson, but not necessarily for other distributions. In particular, selfing decreases heterozygosity and also decreases the number of alleles when the progeny distribution is Poisson, but decreases heterozygosity and increases the number of alleles when there are two progeny per individual. This is because heterozygosity is closely related to the breeding structure (inbreeding) of the population, whereas the number of alleles is more influenced by the variation of the sampling process. Branching processes are employed to model the dynamics of mutant alleles, with drift and subsequent mutation contributing to extinction. In populations of four individuals, double first cousin mating has greater heterozygosity, but fewer alleles, than half-sib mating.
杂合性和等位基因数量都是衡量种群遗传变异的指标。如果子代数量的分布是泊松分布，它们在性质上是相似的，但对于其他分布则不一定。特别是，当子代分布是泊松分布时，自交降低杂合性且也降低等位基因数量，但当每个个体有两个子代时，自交降低杂合性且增加等位基因数量。这是因为杂合性与种群的繁殖结构（近亲繁殖）密切相关，而等位基因数量更多地受抽样过程变异的影响。分支过程用于模拟突变等位基因的动态，其中漂变和随后的突变导致灭绝。在由四个个体组成的种群中，双重表亲交配比半同胞交配具有更高的杂合性，但等位基因数量更少。
