Shorey L, Piertney S, Stone J, Höglund J
Population Biology/EBC, Uppsala University, Sweden.
Nature. 2000 Nov 16;408(6810):352-3. doi: 10.1038/35042562.
Leks have traditionally been considered as arenas where males compete to attract females and secure matings. Thus, direct fitness benefits mediated through competition between males to fertilize females have been considered to be the primary force driving the evolution of lekking behaviour. Inclusive fitness benefits mediated through kin selection may also be involved in lek formation and evolution, but to date this theory has been largely ignored. According to kin-selection theory, both reproducing and non-reproducing males may gain indirect inclusive fitness benefits. If females are attracted to larger leks, non-reproducing males add attractiveness to a lek, and therefore, in a genetically structured population, boost the reproductive success of kin. Theory predicts that the attractiveness of leks is plastic, and that males establish themselves on a lek in which the top male, in terms of reproductive success, is a close relative. Here we show that in white-bearded manakins (Manacus manacus), for which larger leks are more attractive to females and so secure the maximum number of matings, there is extraordinary fine-scale genetic structure, with leks being composed of clusters of related kin. We propose that males establish themselves where they find relatives to such an extent that they form groups within leks, and that such behaviour is consistent with kin-selection theory to maximize reproductive success of the group.
传统上，求偶场被认为是雄性竞争以吸引雌性并确保交配的场所。因此，通过雄性之间竞争使雌性受精而介导的直接适应性益处被视为驱动求偶场行为进化的主要力量。通过亲缘选择介导的广义适应性益处也可能参与求偶场的形成和进化，但迄今为止这一理论在很大程度上被忽视了。根据亲缘选择理论，繁殖雄性和非繁殖雄性都可能获得间接的广义适应性益处。如果雌性被更大的求偶场所吸引，非繁殖雄性会增加求偶场的吸引力，因此，在一个具有遗传结构的种群中，会提高亲属的繁殖成功率。理论预测求偶场的吸引力是可变的，并且雄性会在一个求偶场中立足，在这个求偶场中，就繁殖成功率而言，顶级雄性是近亲。在这里，我们表明，对于白须侏儒鸟（Manacus manacus）来说，更大的求偶场对雌性更具吸引力，从而确保了最多的交配次数，存在着非凡的精细尺度遗传结构，求偶场由相关亲属的集群组成。我们提出，雄性会在找到亲属的地方立足，以至于它们在求偶场内形成群体，并且这种行为与亲缘选择理论一致，以最大化群体的繁殖成功率。
