Arnqvist G, Nilsson T
Department of Ecology and Environmental Science, University of Umeå, Animal Ecology
Anim Behav. 2000 Aug;60(2):145-164. doi: 10.1006/anbe.2000.1446.
Theory suggests that male fitness generally increases steadily with mating rate, while one or a few matings are sufficient for females to maximize their reproductive success. Contrary to these predictions, however, females of the majority of insects mate multiply. We performed a meta-analysis of 122 experimental studies addressing the direct effects of multiple mating on female fitness in insects. Our results clearly show that females gain directly from multiple matings in terms of increased lifetime offspring production. Despite a negative effect of remating on female longevity in species without nuptial feeding, the positive effects (increased egg production rate and fertility) more than outweigh this negative effect for moderate mating rates. The average direct net fitness gain of multiple mating was as high as 30-70%. Therefore, the evolutionary maintenance of polyandry in insects can be understood solely in terms of direct effects. However, our results also strongly support the existence of an intermediate optimal female mating rate, beyond which a further elevated mating rate is deleterious. The existence of such optima implies that sexual conflict over the mating rate should be very common in insects, and that sexually antagonistic coevolution plays a key role in the evolution of mating systems and of many reproductive traits. We discuss the origin and maintenance of nuptial feeing in the light of our findings, and suggest that elaborate and nutritional ejaculates may be the result of sexually antagonistic coevolution. Future research should aim at gaining a quantitative understanding of the evolution of female mating rates. Copyright 2000 The Association for the Study of Animal Behaviour.
理论表明，雄性的适合度通常会随着交配率的增加而稳步提高，而雌性只需进行一次或几次交配就能使生殖成功率最大化。然而，与这些预测相反的是，大多数昆虫的雌性会多次交配。我们对122项关于多次交配对昆虫雌性适合度直接影响的实验研究进行了荟萃分析。我们的结果清楚地表明，雌性通过多次交配直接获得了终生后代产量增加的好处。尽管在没有婚飞喂食的物种中，再次交配会对雌性寿命产生负面影响，但对于适度的交配率来说，积极影响（产卵率和繁殖力增加）远远超过了这种负面影响。多次交配的平均直接净适合度增益高达30% - 70%。因此，昆虫中一妻多夫制的进化维持仅从直接影响方面就能得到理解。然而，我们的结果也有力地支持了存在一个中间最优雌性交配率，超过这个交配率进一步提高就会有害。这种最优情况的存在意味着在昆虫中关于交配率的性冲突应该非常普遍，并且性对抗协同进化在交配系统和许多生殖性状的进化中起着关键作用。我们根据研究结果讨论了婚飞喂食的起源和维持，并提出精心制作且富含营养的精液可能是性对抗协同进化的结果。未来的研究应该旨在对雌性交配率的进化获得定量的理解。版权所有2000动物行为研究协会。
