Eco-evolutionary feedbacks predict the time course of rapid life history evolution

Organisms can change their environment and, in so doing, change the selection they experience and how they evolve. Population density is one potential mediator of such interactions because high population densities can impact the ecosystem and reduce resource availability. At present, such interactions are best known from theory and laboratory experiments. Here we quantify the importance of such interactions in nature by transplanting guppies from a stream where they co-occur with predators into tributaries that previously lacked both guppies and predators. If guppies evolve solely because of the immediate reduction in mortality rate, the strength of selection and rate of evolution should be greatest at the outset then decline as the population adapts to its new environment. If indirect effects caused by the increase in guppy population density in the absence of predation prevail, then there should be a lag in guppy evolution because time is required for them to modify
their envi...

生物能够改变其生存环境，而这种改变反过来会影响它们所经历的选择压力以及进化路径。种群密度是这类相互作用的潜在调节因子之一，因为高种群密度会影响生态系统并降低资源可利用性。目前，这类相互作用主要见于理论研究和实验室实验。本研究通过将与捕食者共存的溪流中的孔雀鱼（guppies）移植到此前既无孔雀鱼也无捕食者的支流中，量化了这类相互作用在自然环境中的重要性。若孔雀鱼仅因死亡率的即时降低而进化，则选择强度和进化速率应在初始阶段达到峰值，随后随着种群适应新环境而下降。若捕食者缺失导致的孔雀鱼种群密度增加所引发的间接效应占主导，则孔雀鱼的进化应存在滞后性，因为它们需要时间来改变其环...