Collaborative Research: A Field-experimental Test for Evolutionary Trait-mediated Indirect Effects in Food Webs

该项目利用加勒比海北部的一组小岛作为模型系统，以了解生态、进化和行为因素之间的相互作用如何决定生物群落的主要特征。该项目以一项大规模实验为中心，在该实验中，大型捕食性蜥蜴的存在/不存在在一系列岛屿上有所不同。大型蜥蜴会影响较小的中型掠食性蜥蜴，这种影响会通过食草性昆虫向下蔓延到植物上。顶端捕食者对低营养水平的影响主要是通过对中间捕食者的影响来实现的。这种影响可以由物种密度的变化驱动，但也可以取决于特定的行为和进化特征。这些性状的变异对食物-网相互作用的影响将在多个世代中得到跟踪。预计中间捕食者最初会减少，但随着它在行为和进化上适应更高的捕食风险，它会恢复。密度变化的模式与栖息地的转移相结合，应该会导致较低水平的食物网发生重大变化。一项与实验平行的比较研究确定了产生实验结果的食物链路径。这项研究将为我们提供关于复杂食物网中生态、行为和进化之间的相互作用的信息。这项研究极大地促进了本科生在野外和实验室研究中的研究经验，并针对在科学中代表不足的群体。这项研究还提供研究生培训，并通过流行文章、公开演示、纪录片和博物馆展品向公众传播研究结果。尽一切努力将这项研究与应用科学联系起来，例如改善农业生态系统，处理生物入侵，保护物种和栖息地。

This project utilizes a set of small islands in the northern Caribbean as a model system to understand how interactions between ecological, evolutionary and behavioral factors determine major features of biological communities. The project centers on a large-scale experiment in which presence/absence of large predatory lizards is varied across a series of islands. Large lizards affect smaller, intermediate-size predatory lizards, and the effects cascade down through insect herbivores to the plants. The effects of the top predator on lower trophic levels are mediated largely through effects on the intermediate predator. Such effects can be driven by changes in species densities, but can also depend on specific behavioral and evolutionary traits. The effects of variation in these traits on food-web interactions will be followed over multiple generations. The intermediate predator would be expected to initially decrease but then recover as it behaviorally and evolutionarily adjusts to increased predation risk. The pattern of density change combined with the habitat shift should cause major changes in lower levels of the food web. A comparative study parallels the experiment to determine the food-web pathways generating the experimental results. This study will inform us regarding the interplay between ecology, behavior, and evolution in complex food webs.This study substantially promotes undergraduate research experiences in field and lab studies and targets groups underrepresented in science. The study also provides graduate-student training and communicates findings to the public via popular articles, public presentations, documentary films, and museum exhibits. Every effort is made to relate this research to applied sciences such as improving agroecosystems, dealing with biological invasions, and preserving species and habitats.