Blomqvist Donald, Andersson Malte, Küpper Clemens, Cuthill Innes C, Kis János, Lanctot Richard B, Sandercock Brett K, Székely Tamás, Wallander Johan, Kempenaers Bart
Konrad Lorenz Institute for Comparative Ethology, Austrian Academy of Sciences, Savoyenstrasse 1a, A-1160 Vienna, Austria.
Nature. 2002 Oct 10;419(6907):613-5. doi: 10.1038/nature01104.
Matings between close relatives often reduce the fitness of offspring, probably because homozygosity leads to the expression of recessive deleterious alleles. Studies of several animals have shown that reproductive success is lower when genetic similarity between parents is high, and that survival and other measures of fitness increase with individual levels of genetic diversity. These studies indicate that natural selection may favour the avoidance of matings with genetically similar individuals. But constraints on social mate choice, such as a lack of alternatives, can lead to pairing with genetically similar mates. In such cases, it has been suggested that females may seek extra-pair copulations with less related males, but the evidence is weak or lacking. Here we report a strong positive relationship between the genetic similarity of social pair members and the occurrence of extra-pair paternity and maternity ('quasi-parasitism') in three species of shorebirds. We propose that extra-pair parentage may represent adaptive behavioural strategies to avoid the negative effects of pairing with a genetically similar mate.
近亲交配往往会降低后代的适应性，这可能是因为纯合性会导致隐性有害等位基因的表达。对几种动物的研究表明，当父母之间的遗传相似性较高时，繁殖成功率较低，而且生存能力和其他适应性指标会随着个体遗传多样性水平的提高而增加。这些研究表明，自然选择可能有利于避免与遗传相似的个体交配。但是，社会配偶选择的限制，如缺乏选择机会，可能导致与遗传相似的配偶配对。在这种情况下，有人认为雌性可能会寻求与亲缘关系较近的雄性进行额外配偶交配，但证据不足或缺乏。在此，我们报告了三种滨鸟的社会配偶成员的遗传相似性与额外配偶父权和母权（“准寄生”）的发生之间存在强烈的正相关关系。我们认为，额外配偶亲子关系可能代表了适应性行为策略，以避免与遗传相似的配偶配对所带来的负面影响。
