Prudent predators catch sufficient prey to sustain their populations but not as much as to undermine their populations’ survival. The idea that predators evolve to be prudent has been dismissed in the 1970s, but the arguments invoked then are untenable in the light of modern evolution theory. The evolution of prudent predation has repeatedly been demonstrated in two-species predator–prey metacommunity models. However, the vigorous population fluctuations that these models predict are not widely observed. Here we show that in complex model food webs prudent predation evolves as a result of consumer-mediated (‘apparent’) competitive exclusion of resources, which disadvantages aggressive consumers and does not generate such fluctuations. We make testable predictions for empirical signatures of this mechanism and its outcomes. Then we discuss how these predictions are borne out across freshwater, marine and terrestrial ecosystems. Demonstrating explanatory power of evolved prudent predation well beyond the question of predator–prey coexistence, the predicted signatures explain unexpected declines of invasive alien species, the shape of stock–recruitment relations of fish, and the clearance rates of pelagic consumers across the latitudinal gradient and 15 orders of magnitude in body mass. Specific research to further test this theory is proposed.

中文翻译：

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复杂食物网中谨慎捕食的演变

谨慎的捕食者会捕获足够的猎物来维持其种群，但不会破坏其种群的生存。掠食者进化为谨慎的想法在 1970 年代已被驳回，但根据现代进化论，当时所引用的论点是站不住脚的。谨慎捕食的演变已在两种捕食者 - 猎物元群落模型中反复得到证明。然而，这些模型预测的剧烈人口波动并未得到广泛观察。在这里，我们表明，在复杂的食物网模型中，谨慎的捕食行为是由于消费者介导的（“明显的”）竞争性排斥资源而演变的，这对激进的消费者不利，并且不会产生这种波动。我们对这种机制及其结果的经验特征做出可测试的预测。然后我们讨论这些预测如何在淡水、海洋和陆地生态系统中得到证实。证明进化的谨慎捕食的解释力远远超出了捕食者 - 猎物共存的问题，预测的特征解释了入侵外来物种的意外下降，鱼类种群 - 招募关系的形状，以及在纬度梯度和中上层消费者的清除率体重增加了 15 个数量级。提出了进一步检验这一理论的具体研究。以及跨纬度梯度和体重15个数量级的远洋消费者的清除率。提出了进一步检验这一理论的具体研究。以及跨纬度梯度和体重15个数量级的远洋消费者的清除率。提出了进一步检验这一理论的具体研究。