Centre for Evolutionary Biology, The University of Western Australia, M092, 35 Stirling Highway, 6009 Crawley, Australia.
Evolution. 2012 Dec;66(12):3778-88. doi: 10.1111/j.1558-5646.2012.01721.x. Epub 2012 Jul 15.
Monogamy results in high genetic relatedness among offspring and thus it is generally assumed to be favored by kin selection. Female multiple mating (polyandry) has nevertheless evolved several times in the social Hymenoptera (ants, bees, and wasps), and a substantial amount of work has been conducted to understand its costs and benefits. Relatedness and inclusive fitness benefits are, however, not only influenced by queen mating frequency but also by paternity skew, which is a quantitative measure of paternity biases among the offspring of polyandrous females. We performed a large-scale phylogenetic analysis of paternity skew across polyandrous social Hymenoptera. We found a general and significant negative association between paternity frequency and paternity skew. High paternity skew, which increases relatedness among colony members and thus maximizes inclusive fitness gains, characterized species with low paternity frequency. However, species with highly polyandrous queens had low paternity skew, with paternity equalized among potential sires. Equal paternity shares among fathers are expected to maximize fitness benefits derived from genetic diversity among offspring. We discuss the potential for postcopulatory sexual selection to influence patterns of paternity in social insects, and suggest that sexual selection may have played a key, yet overlooked role in social evolution.
单配制导致后代之间具有高度的遗传相关性，因此通常认为其受到亲缘选择的青睐。然而，在社会性膜翅目昆虫（蚂蚁、蜜蜂和黄蜂）中，雌性多次交配（多配偶制）已经进化了多次，并且已经进行了大量的工作来理解其成本和收益。然而，亲缘关系和适合度收益不仅受蜂王交配频率的影响，还受父权偏倚的影响，父权偏倚是衡量多配偶制雌性后代中父权偏差的一种定量衡量标准。我们对多配偶制社会性膜翅目昆虫的父权偏倚进行了大规模的系统发育分析。我们发现父权频率和父权偏倚之间存在普遍而显著的负相关。高父权偏倚会增加群体成员之间的亲缘关系，从而最大限度地提高适合度收益，这一特征存在于父权频率较低的物种中。然而，具有高度多配偶制的蜂王的父权偏倚较低，潜在的父亲之间的父权平等化。期望父亲之间平等的父权份额能最大限度地提高从后代遗传多样性中获得的适应度收益。我们讨论了种间性选择可能对社会性昆虫的父权模式产生影响的可能性，并认为性选择可能在社会进化中发挥了关键但被忽视的作用。
