Quantifying trade‐offs within populations is important in life‐history theory. However, most studies focusing on life‐history trade‐offs focus on two traits and assume trade‐offs to be static. Our work provides a framework for understanding covariation among multiple traits and how population density influences the traits. Using detailed individual‐based data for Soay sheep, we find density strongly shapes life‐history trade‐offs and distribution of lifetime reproductive success (LRS). At low density, a trade‐off between juvenile survival and growth structures life‐history variation, whereas at equilibrium density, trade‐off between reproduction and juvenile survival is the major structuring axes. Contrary to Lomnicki's prediction, we find that at high density, there is little variation in the LRS over the sizes (large juveniles and adults) that contribute to reproduction. Our results advance an understanding of dynamic nature of trade‐offs offer insights into how high‐density limits diversity of individual life histories and have implications for evolution via density‐dependent selection.

中文翻译：

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密度依赖性决定了食物有限人群的生活史权衡


量化种群内部的权衡在生活史理论中很重要。然而，大多数专注于生活史权衡的研究都集中在两个特征上，并假设权衡是静态的。我们的工作为理解多个性状之间的协变以及种群密度如何影响性状提供了一个框架。使用大豆羊的详细个体数据，我们发现密度强烈影响了生活史权衡和终生繁殖成功 （LRS） 的分布。在低密度下，幼年存活率和生长之间的权衡构建了生活史变化，而在平衡密度下，繁殖和幼年存活率之间的权衡是主要的结构轴。与 Lomnicki 的预测相反，我们发现在高密度下，LRS 对有助于繁殖的大小（大型幼体和成体）几乎没有变化。我们的结果促进了对权衡动态性质的理解，提供了对高密度如何限制个体生活史多样性的见解，并通过密度依赖性选择对进化产生影响。