Charlesworth Deborah, Willis John H
Institute for Evolutionary Biology, Ashworth Laboratories, King's Buildings, University of Edinburgh, West Mains Road, Edinburgh EH9 3JT, UK.
Nat Rev Genet. 2009 Nov;10(11):783-96. doi: 10.1038/nrg2664.
Inbreeding depression - the reduced survival and fertility of offspring of related individuals - occurs in wild animal and plant populations as well as in humans, indicating that genetic variation in fitness traits exists in natural populations. Inbreeding depression is important in the evolution of outcrossing mating systems and, because intercrossing inbred strains improves yield (heterosis), which is important in crop breeding, the genetic basis of these effects has been debated since the early twentieth century. Classical genetic studies and modern molecular evolutionary approaches now suggest that inbreeding depression and heterosis are predominantly caused by the presence of recessive deleterious mutations in populations.
近亲繁殖衰退——即亲缘关系较近的个体所产后代的存活率和生育力降低——在野生动物和植物种群以及人类中都会出现，这表明自然种群中存在适应性性状的遗传变异。近亲繁殖衰退在异交交配系统的进化中很重要，而且由于杂交近交系可提高产量（杂种优势），这在作物育种中很重要，自20世纪初以来，这些效应的遗传基础一直存在争议。经典遗传学研究和现代分子进化方法现在表明，近亲繁殖衰退和杂种优势主要是由种群中隐性有害突变的存在引起的。
