Evolution, Coevolution and Predator-Prey Dynamics: An Experimental Approach

[9419660 . 60]进化理论预测，捕食者会引起猎物的进化变化，而捕食者可能会对猎物做出反应而进化。这种变化被认为会影响捕食者和猎物的种群动态。然而，这一重要的进化理论领域实际上是未经检验的，因为需要长期的研究来观察大多数动物的进化和种群动态。这个问题可以通过研究微生物的进化来解决，微生物的进化速度很快，因为它们的繁殖时间只有4-48小时。发现进化是否能改变种群动态，确定进化过程是否需要纳入种群生物学理论是至关重要的。这些知识可能会提高科学家预测种群规模变化的能力。在这个项目中，原生动物捕食者和它们的猎物将在复制的实验室微观环境中生长，在那里它们的种群动态和其他特征可以相对容易地测量。该项目由四组实验组成，每组实验针对一对不同的捕食者-猎物。猎物将生长超过100代，仅在微观世界中与捕食者一起生长。在此期间，将定期测量各种捕食者和猎物的特征，以量化进化变化。人口规模也将受到监测。随后的实验将测量进化对捕食者-猎物种群动态的影响。在这些实验中，来自第一个实验的捕食者将与两种类型的猎物中的一种一起生长：数百代未与捕食者共存的猎物，或数百代已与捕食者共存的猎物。当在两种类型的猎物上生长时，捕食者种群动态的差异将提供进化影响种群动态的证据。这项研究将澄清种群生物学家在构建种群动态预测模型时是否需要考虑进化过程，并可能确定在捕食者-猎物对中是否发生共同进化。这项研究将验证的理论对应用生态学中的一些问题具有潜在的重要意义。例如，了解害虫物种是否能够迅速进化出对为生物防治而引入的捕食者的抗性是很重要的。

9419660 Lawler Evolutionary theory predicts that predators can cause evolutionary change in their prey and that predators may evolve in response to their prey. Such changes are thought to affect the population dynamics of both predators and prey. However, this important realm of evolutionary theory is practically untested because prolonged studies are required to observe evolution and population dynamics in most animals. This problem can be overcome by studying evolution in micro-organisms, which can evolve rapidly because their generation times are only 4-48 hours. It is crucial to discover whether evolution can alter population dynamics, to determine whether evolutionary processes need to be incorporated into population biology theory. Such knowledge may increase the ability of scientists to predict changes in population sizes. In this project, protozoan predators and their prey will be grown in replicated laboratory microcosms, where their population dynamics and other characteristics can be measured with comparative ease. The project consists of four sets of experiments, each on a different predator-prey pair. Prey will be grown for over 100 generations, in microcosms alone and with predators. A wide variety of predator and prey characters will be measured regularly during this time to quantify evolutionary changes. Population sizes will also be monitored. Subsequent experiments will measure the effect of evolution on predator-prey population dynamics. In these, predators from the first experiment will be grown with either of two types of prey: prey that have not coexisted with the predator for hundreds of generations, or prey that have. Differences in the population dynamics of the predator when grown on the two prey types will provide evidence that evolution affects population dynamics. This research will clarify whether population biologists need to consider evolutionary processes when constructing predictive models of population dynamics, and may establish whether coevolution o ccurs in predator-prey pairs. The theory that this research will test is potentially important to some problems in applied ecology. For example, it is important to know whether pest species can rapidly evolve resistance to predators introduced for biological control.