Senders & Their Sensory Environments: Acoustic Lessons From a Radiation of Ancient Grasshoppers

个体之间的交流最终取决于感觉器官的功能，如眼睛或耳朵，并受到各种因素的影响，从微生境中信号传输的物理学到外周受体器官的神经特性。 尽管人们已经对择偶场景进行了彻底的研究，但环境和感觉系统之间的进化联系实际上仍然没有被探索。 值得注意的例外发生在相当先进的脊椎动物群体，如青蛙和鱼类。 然而，几乎可以肯定的是，脊椎动物的中枢神经系统比周围神经系统更具可塑性，而且在这个水平上感觉特征的变化很难评估。 相比之下，无脊椎动物的感觉变化是相当多的集中在外围，因此无脊椎动物可能提供有用的模型系统。 膀胱蝗虫（直翅目，蝗虫科）是高度专业化的长距离（~2公里）的声音信号，目前占据了一系列的对比感官生态环境。 这个小家庭，其中每个人都有两种不同类型的十几只耳朵，提供了一个独特的机会来研究感官生物学在进化过程中的作用。 环境的限制和耳朵的结构和功能的贡献将在这个古老的群体中进行探索。 为了确定栖息地是否是不同鸣叫的重要选择压力，将进行一系列声学回放实验来比较森林、草原和沙漠栖息地中声音传输的效率。 详细的形态结构的鼓和胸膜的耳朵将进行比较，跨物种，和微扫描激光振动仪将产生相对估计的耳朵调谐和灵敏度。 这些将表明耳朵在多大程度上与物种特异性叫声的频谱相匹配，以及不同栖息地之间感官分区的潜力。 最后，将使用线粒体16 S rRNA基因的DNA测序来重建肺炎科家族的进化历史，为综合比较分析提供基础设施。该项目涉及国际旅行，并将与几个本科生，研究生和博士后合作进行。 这项研究的结果将提供深入了解环境和感觉系统之间存在的复杂关联，以及这些相互作用在物种形成过程中的潜在作用。 此外，这些独特的无脊椎动物耳朵的进化特征可能与小型高灵敏度听力设备的设计有关。

Communication between individuals is ultimately dependent on the functioning of sensory organs, such as eyes or ears, and is affected by a variety of factors, ranging from the physics of signal transmission in the microhabitat, to the neural characteristics of peripheral receptor organs. Although mate choice scenarios have been thoroughly investigated, the evolutionary links between the environment and sensory systems remain virtually unexplored. Notable exceptions occur in fairly advanced vertebrate groups such as frogs and fish. However, the vertebrate central nervous system is almost certainly more plastic than is the peripheral nervous system, and changes in sensory characteristics at this level are difficult to evaluate. In contrast, sensory change in invertebrates is considerably more concentrated at the periphery, thus invertebrates may provide useful model systems. Bladder grasshoppers (Orthoptera, Pneumoridae) are highly specialized for long distance (~2 km) acoustic signaling and presently occupy a range of contrasting sensory-ecological environments. This small family, in which each individual has a dozen ears of two distinct types, offers a unique opportunity to investigate the role of sensory biology in evolutionary processes. The contributions of environmental constraints and ear structure and function will be explored in this ancient group. To determine whether habitat is a significant selection pressure for divergent calling songs, a series of acoustic playback experiments will be performed to compare the efficiency of sound transmission in forest, grassland and desert habitats. The detailed morphological structure of both a tympanate- and pleural ears will be compared across species, and microscanning laser vibrometry will yield relative estimates of ear tuning and sensitivity. These will indicate to what extent ears are matched to the frequency spectra of species-specific calls, and the potential for sensory partitioning across different habitats. Finally, the evolutionary history of the pneumorid family will be reconstructed using DNA sequencing of the mitochondrial 16S rRNA gene to provide the infrastructure for integrated comparative analyses. This project involves international travel, and will be carried out in collaboration with several undergraduate, graduate, and post-doctoral associates. The results of this study will provide insight into the complex associations that exist between the environment and sensory systems, and the potential role of these interactions in the speciation process. Moreover, evolved features of these unique invertebrate ears may be relevant in the design of small, highly sensitive hearing devices.