Hammond R L, Bruford M W, Bourke A F G
Institute of Zoology, Zoological Society of London, London, UK.
J Evol Biol. 2003 May;16(3):446-55. doi: 10.1046/j.1420-9101.2003.00544.x.
Kin selection theory predicts that, in social Hymenoptera, the parentage of males should be determined by within-colony relatedness. We present a model showing that, when sex ratios are split (bimodal) as a function of colony kin structure, the predictions of kin selection theory regarding the occurrence of worker reproduction and policing (prevention of worker reproduction) require modification. To test the predictions of kin selection theory and our model, we estimated using microsatellites the frequency of worker-produced male eggs and adults in the facultatively polygynous (multiple-queen) ant Leptothorax acervorum. Analysis of 210 male eggs and 328 adult males from 13 monogynous (single-queen) and nine polygynous colonies demonstrated that the frequency of worker-produced males was low (2.3-4.6% of all males) and did not differ significantly between colony classes or between eggs and adults. This suggested workers' self-restraint as the cause of infrequent worker reproduction in both colony classes. Such an outcome is not predicted either by comparing relatedness values or by our model. Therefore, it appears that factors other than colony kin structure and sex ratio effects determine the pattern of male parentage in the study population. A likely factor is a colony-level cost of worker reproduction.
亲缘选择理论预测，在社会性膜翅目昆虫中，雄性的亲本关系应由蚁群内的亲缘关系决定。我们提出了一个模型，该模型表明，当性别比例作为蚁群亲缘结构的函数呈分裂状态（双峰分布）时，亲缘选择理论中关于工蚁繁殖和监管（防止工蚁繁殖）发生情况的预测需要修正。为了检验亲缘选择理论和我们模型的预测，我们使用微卫星估计了兼性多雌型（多蚁后）蚂蚁聚群蚁中由工蚁产生的雄性卵和成虫的频率。对来自13个单雌型（单蚁后）和9个多雌型蚁群的210枚雄性卵和328只成年雄性蚂蚁的分析表明，由工蚁产生的雄性蚂蚁的频率较低（占所有雄性蚂蚁的2.3 - 4.6%），在蚁群类型之间或卵与成虫之间没有显著差异。这表明工蚁的自我克制是两种蚁群类型中工蚁繁殖不常见的原因。无论是通过比较亲缘关系值还是我们的模型，都无法预测到这样的结果。因此，似乎除了蚁群亲缘结构和性别比例影响之外的其他因素决定了研究种群中雄性亲本关系的模式。一个可能的因素是工蚁繁殖的蚁群层面成本。
