为何雄性会选择竞争而非照料——应用于集体物品供给的研究
Why males compete rather than care, with an application to supplying collective goods
AI总结：
本文针对进化生物学中雄性竞争多于照料的问题，构建动态模型分析两种适合度提升路径的收益，结合大型猎物狩猎应用发现，在特定参数与频率依赖条件下，竞争可使雄性获得更高适合度。
AI中文摘要：
雄性为何在竞争上的投入多于后代照料，是进化生物学中由来已久的问题。一方面，父本照料可提高后代存活至成熟的比例；另一方面，竞争能增加获得更多父权的概率，从而提高所产后代的相对数量。尽管这些行为的驱动因素常与诸多其他约束交织，本文提出一个简单的动态模型，以探究这两种提升适合度的替代路径的收益。利用该框架，我们评估了平衡动态对雄性在交配与抚育间分配的收益变化的敏感性。即便照料对后代存活有强效应，微小的竞争收益也能超过照料的收益。我们考虑了该模型的一个应用场景，即男性为狩猎声誉而竞争，大型猎物为所有人提供收益，发现存在一个频率依赖的参数区域，在此区域内，根据初始种群比例，任一策略都可能优于另一策略。结果表明，在一系列取决于生活史参数的情况下，以及对于大型猎物狩猎的应用而言，频率依赖的情况下，分配给竞争会使雄性比后代照料获得更高的适合度。集体收益越大，越能选择更多个体来提供该收益。
英文摘要：
The question of why males invest more into competition than offspring care is an age-old problem in evolutionary biology. On one hand, paternal care could increase the fraction of offspring surviving to maturity. On the other hand, competition could increase the likelihood of more paternities and thus the relative number of offspring produced. While drivers of these behaviours are often intertwined with a wide range of other constraints, here we present a simple dynamic model to investigate the benefits of these two alternative fitness-enhancing pathways. Using this framework we evaluate the sensitivity of equilibrium dynamics to changes in payoffs for male allocation to mating versus parenting. Even with strong effects of care on offspring survivorship, small competitive benefits can outweigh benefits from care. We consider an application of the model that includes men's competition for hunting reputations where big game supplies a benefit to all, and find a frequency-dependent parameter region within which, depending on initial population proportions, either strategy may outperform the other. Results demonstrate that allocation to competition gives males greater fitness than offspring care for a range of circumstances that are dependent on life-history parameters and, for the large-game hunting application, frequency dependent. The greater the collective benefit, the more individuals can be selected to supply it.
