Just as intraorganismal selection can produce "selfish" elements that lower individual fitness, selection at the organismal level can favour traits that reduce the fitness of conspecifics and potentially impact population survival. Because dispersal can affect how these traits are distributed within species, it may determine whether their negative consequences are restricted locally or spread throughout the species' range. We present an individual-based simulation model that explores the interaction between dispersal rate and traits that increase individual fecundity at the expense of conspecific fitness. We first modelled dispersal as a trait that varied within species and then fixed the within-species dispersal rates and modelled competition between species that differed only in dispersal rate. Reproductive isolation allowed species differences in dispersal rates to become associated with traits moulded by intraspecific competition, but this association did not occur when dispersal variation was distributed within species due to recombination between the dispersal and competition loci. Alleles that reduced the fitness of conspecifics were maintained at lower frequencies in low-dispersal species, resulting in a competitive advantage over high-dispersing species. Although high-dispersal species initially outcompeted low-dispersal species owing to enhanced colonization opportunities, low-dispersal species ultimately showed greater representation across a range of ecological and genetic scenarios. This process may shift the makeup of communities over time towards a greater representation of low-dispersal species.

中文翻译：

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散布通过传播局部有害特性降低了种间竞争力。

正如生物体内选择会产生降低个体适应度的“自私”因素一样，生物体水平的选择可能有利于降低同种适应度并可能影响种群生存的特征。由于扩散会影响这些性状在物种内的分布方式，因此可能决定它们的负面影响是在局部受到限制还是在整个物种范围内传播。我们提出了一个基于个体的模拟模型，该模型探索了扩散率与以牺牲同种适应性为代价增加个体繁殖力的性状之间的相互作用。我们首先将扩散建模为一种在物种内变化的性状，然后固定物种内扩散率并模拟仅扩散率不同的物种之间的竞争。生殖隔离允许物种扩散率的差异与种内竞争塑造的性状相关，但当扩散变异由于扩散和竞争基因座之间的重组而分布在物种内时，这种关联不会发生。降低同种适应性的等位基因在低扩散物种中保持较低的频率，从而比高扩散物种具有竞争优势。尽管由于殖民机会增加，高扩散物种最初在竞争中胜过低扩散物种，但低扩散物种最终在一系列生态和遗传场景中表现出更大的代表性。随着时间的推移，这个过程可能会改变社区的构成，以更多地代表低扩散物种。