Data from: Consumer-resource interactions and the evolution of migration

Theoretical studies have demonstrated that selection will favor increased migration when fitnesses vary both temporally and spatially, but it is far from clear how pervasive those theoretical conditions are in nature. While consumer-resource interactions are omnipresent in nature and can generate spatial and temporal variation, it is unknown even in theory whether these dynamics favor the evolution of migration. We develop a mathematical model to address whether and how migration evolves when variability in fitness is determined at least in part by consumer-resource coevolutionary interactions. Our analyses show that such interactions can drive the evolution of migration in the resource, consumer, or both species and thus supplies a general explanation for the pervasiveness of migration. Over short time scales, we show the direction of change in migration rate is determined primarily by the state of local adaptation of the species involved: rates increase when a species is locally maladapted and decrease when locally adapted. Our results reveal that long-term evolutionary trends in migration rates can differ dramatically depending on the strength or weakness of interspecific interactions and suggest an explanation for the evolutionary divergence of migration rates among interacting species.

理论研究已证实，当适合度（fitness）同时存在时间与空间异质性时，自然选择会青睐更高的迁移率，但目前仍不清楚这些理论前提在自然界中的普遍程度。消费者-资源（consumer-resource）相互作用在自然界中无处不在，且能够催生空间与时间维度的异质性，但即便在理论层面，我们仍无法确定这类生态动态是否会推动迁移的演化。我们构建了一个数学模型，旨在探讨当适合度的异质性至少部分由消费者-资源协同进化相互作用所决定时，迁移是否会发生演化以及其具体演化路径。我们的分析结果显示，这类相互作用能够推动资源物种、消费者物种或二者同时发生迁移演化，从而为迁移现象在自然界中的普遍性提供了一般性解释。在短时间尺度下，我们发现迁移率的变化方向主要由所涉及物种的本地适应（local adaptation）状态决定：当物种处于本地不适应当地环境的状态时，迁移率会上升；而当物种适应当地环境时，迁移率则会下降。我们的研究还揭示，迁移率的长期演化趋势会因种间相互作用的强弱而呈现显著差异，这为相互作用物种间迁移率的演化分化提供了合理的解释。