Prey diversity constrains the adaptive potential of predator foraging traits

Predators are generally under selective pressure to get better at foraging, leading to steeper functional responses and stronger predator-prey interactions. Yet strong interactions can de-stabilize food webs, and most interactions across ecological communities are thought to be weak. This conflict between evolutionary and community expectations for the strength of predator-prey interactions represents a fundamental gap in our understanding of how the evolution of foraging plays out in food webs. Here we help to resolve the conflict by showing analytically that the expectation for the evolution of steeper functional responses is relaxed in communities with diverse prey types. We simulate communities with varying prey richness and show that increasing prey richness can indeed constrain the adaptive potential of predator foraging traits, but that at low prey richness predators can evolve to have a stronger interaction with prey that have high net energy yields. Our results also indicate th...捕食者通常面临着提升觅食效率的选择压力，进而演化出更陡峭的功能响应（functional response）以及更强的捕食者-猎物相互作用。然而较强的相互作用会破坏食物网的稳定性，而学界普遍认为生态群落中的绝大多数相互作用都较为微弱。这种针对捕食者-猎物相互作用强度的演化预期与群落生态预期之间的矛盾，是当前我们理解觅食行为演化如何在食物网中运作的核心认知空白。本研究通过解析分析表明，在猎物类型多样的群落中，对捕食者演化出更陡峭功能响应的预期会被放宽，从而助力解决这一矛盾。我们模拟了猎物丰富度各异的群落，结果显示提升猎物丰富度确实能够限制捕食者觅食性状的适应性演化潜力；而在猎物丰富度较低的情境下，捕食者则可演化出与净能量收益较高的猎物形成更强的相互作用。本研究结果同时表明……