Collaborative Research: Origins of Diversity in Animal Communication: Habitat-dependent Adaptive Change in Lizard Visual Displays

为了让动物有效地交流，它们必须产生对环境中的接受者来说显而易见的信号。因此，动物被期望进化出信号形式，这些形式被量身定做，在它们生活的栖息地中引人注目。信号需要在使用它们的环境中“脱颖而出”这一概念对进化生物学具有有趣的影响。例如，如果一个物种的成员使用视觉信号进入一个新的环境，与他们以前的环境具有不同的视觉特征，人们会期望他们的信号在那个新的环境中进化得更加明显。另一方面，从比较研究中我们也知道，信号的进化是有限制的，一个物种的进化历史可能会影响它调整信号以适应当前环境条件的方式。然而，目前尚不清楚环境条件和系统发育如何相互作用，影响在动物群体中观察到的信号形式的多样性，这些动物的成员目前生活在广泛的不同环境中。这项研究考察了信号环境的特性和系统发育效应如何解释牙买加和波多黎各Anolis蜥蜴精心制作的视觉显示的差异。反常动作包括固定的头部上下运动--“头波头”--和一个可伸缩的喉扇--“露珠”--用来维护和保卫领地。研究人员将记录和分析一些不同物种在野外自然条件下产生的展示，这些物种生活在具有不同视觉特征的环境中。这些数据将被用来确定生活在可比较环境中的物种的显示特征在多大程度上相似(显示行为的趋同)，以及显示特征受进化历史影响的程度，即，即使生活在不同的环境中，密切相关的物种是否具有相似的显示特征。基于从自由生活的蜥蜴收集的数据，一种可编程的机器蜥蜴将被用来向野外的蜥蜴呈现不同的信号模式，并测试展示、栖息地特征和系统发育之间的因果联系。这项研究涉及一些本科生的参与，他们将获得在实地条件下进行研究、数据处理/分析以及与同行和专业会议进行科学交流的实践经验。在野外收集的蜥蜴展示的视频片段也将为一个新的入门生物学实验室提供基础，该实验室旨在向本科生传授进化的一般原理。这个实验室将扩展为一个更高级的基于网络的模块，用于更高层次的行为生态学和进化课程，最终将通过互联网发布给其他教育工作者。研究期间汇编的视频库和动作分析数据将代表对任何分类组进行的最详细的动态视觉显示调查。在该项目完成后，这个数据库将通过一个基于网络的公共行为信息储存库免费提供给其他研究人员。

For animals to communicate efficiently, they must produce signals that are obvious to receivers in the environment. Animals are therefore expected to evolve signal forms, which are tailored to be conspicuous within the habitats in which they live. The notion that signals need to 'stand out' in the environment in which they are used has interesting implications for evolutionary biology. For instance, if the members of a species using visual signals move into a new environment, with different visual characteristics from their previous environment, one would expect their signals to evolve to become more conspicuous in that new environment. On the other hand, we also know from comparative studies that there are constraints on the evolution of signals, and that the evolutionary history of a species may affect the ways in which it adjusts its signals to suit the conditions in its current environment. At this point, however, it is unclear how environmental conditions and phylogeny interact to affect the diversity of signal forms that are observed in groups of animals whose members currently live in a wide array of different environments. This study examines how properties of the signal environment and phylogenetic effects explain variation in the elaborate visual displays of Jamaican and Puerto Rican Anolis lizards. Anole displays consist of stereotyped up/down movements of the head - 'head-bob' - and a retractable throat fan - 'dewlap' - and are used to maintain and defend territories. The investigators will record and analyze the displays produced under natural conditions in the field by a number of different species, living in environments with different visual characteristics. These data will be used to determine the extent to which the display characteristics of distantly-related species are similar for species living in comparable environments (convergence in display behavior), and the extent to which display characteristics are affected by evolutionary history, i.e., whether closely-related species have similar display characteristics, even though they live in different environments. Based on the data collected from free-living lizards, a programmable robot lizard will be used to present alternative signal patterns to lizards in the field and test causal links between displays, habitat characteristics and phylogeny. The research involves the participation of a number of undergraduate students, who will be given hands-on experience in conducting research under field conditions, data processing/analysis, and communicating science with their peers and at professional meetings. Video footage of lizard displays collected in the field will also provide the basis for a new introductory biology lab designed to teach undergraduates general principles of evolution. This lab will be expanded into a more advanced web-based module for upper level behavioral ecology and evolution courses, which will ultimately be released to other educators over the Internet. The video library and motion analysis data compiled during the study will represent the most detailed survey of dynamic visual displays conducted for any taxonomic group. At the project's completion, this database will be made freely available to other researchers through a web-based public repository of behavioral information.