Sanderson Brian J, Augat Malcolm E, Taylor Douglas R, Brodie Edmund D
Mountain Lake Biological Station and Department of Biology University of Virginia 485 McCormick Road Charlottesville Virginia 22904.
Ecol Evol. 2016 Feb 3;6(5):1411-9. doi: 10.1002/ece3.1958. eCollection 2016 Mar.
Social context refers to the composition of an individual's social interactants, including potential mates. In spatially structured populations, social context can vary among individuals within populations, generating the opportunity for social selection to drive differences in fitness functions among individuals at a fine spatial scale. In sexually polymorphic plants, the local sex ratio varies at a fine scale and thus has the potential to generate this opportunity. We measured the spatial distribution of two wild populations of the gynodioecious plant Silene vulgaris and show that there is fine-scale heterogeneity in the local distribution of the sexes within these populations. We demonstrate that the largest variance in sex ratio is among nearest neighbors. This variance is greatly reduced as the spatial scale of social interactions increases. These patterns suggest the sex of neighbors has the potential to generate fine-scale differences in selection differentials among individuals. One of the most important determinants of social interactions in plants is the behavior of pollinators. These results suggest that the potential for selection arising from sex ratio will be greatest when pollen is shared among nearest neighbors. Future studies incorporating the movement of pollinators may reveal whether and how this fine-scale variance in sex ratio affects the fitness of individuals in these populations.
社会环境指的是个体社会互动对象的构成，包括潜在配偶。在空间结构的种群中，社会环境在种群内的个体间可能存在差异，从而为社会选择创造了机会，促使个体在精细的空间尺度上产生适合度函数的差异。在具有性别多态性的植物中，局部性别比例在精细尺度上存在变化，因此有可能创造出这种机会。我们测量了雌雄异株植物普通麦瓶草两个野生种群的空间分布，结果表明这些种群内性别在局部分布上存在精细尺度的异质性。我们证明，性别比例的最大差异存在于最近邻个体之间。随着社会互动空间尺度的增加，这种差异会大幅减小。这些模式表明，邻居的性别有可能在个体间的选择差异上产生精细尺度的差异。植物中社会互动最重要的决定因素之一是传粉者的行为。这些结果表明，当花粉在最近邻个体间共享时，由性别比例产生的选择潜力将最大。纳入传粉者移动情况的未来研究可能会揭示这种性别比例的精细尺度差异是否以及如何影响这些种群中个体的适合度。
