Basic Mechanisms and Evolution of Acoustic Communication

Gerhardt，Carl IBN-9507394 标题：声学通信的基本机制和演变 摘要 通过研究灰树蛙复合体作为模型系统的成员，将实现获得有关声学通信的基本机制和进化的知识的主要目标。 这些树蛙的雄性会发出一小套刻板的、未经学习的信号，而雌性则完全根据这些信号来选择配偶。 在回放实验中使用合成的、计算机生成的声音将被用来识别来自整个综合体范围内不同人群的女性从这些信号中提取的确切声学标准。 一个主要的选择因素，可能形成种群之间的差异是声学社区的复杂性，和女性的选择性，因此将比较两个种群之间，遗传上不相容的成员的复杂共存的种群中，只有一个单一的物种出现。 进一步的实验将探索增加声学复杂性（背景噪声和竞争信号的数量）对种群内配偶选择的影响。最后，灰色树蛙复合体由三个谱系的四倍体，具有相似的声学结构的声学信号。 由于这些谱系被认为是独立出现的，并且是通过同源多倍体（由环境因素引起的染色体数目加倍）在一代中出现的，因此出现了他们如何从二倍体祖先中实现行为隔离的问题。 伴随同源多倍体的细胞大小和数量的变化对呼叫结构、雌性选择标准或两者都有行为上重要的影响，这一假设将通过从二倍体个体的冷休克卵中创建人工多倍体来进行测试。

Gerhardt, Carl IBN-9507394 Title: Basic Mechanisms and Evolution of Acoustic Communication Abstract The main goal of gaining knowledge about basic mechanisms and evolution of acoustic communication will be accomplished by studying members of the gray treefrog complex as a model system. Males of these treefrogs produce a small set of stereotyped, unlearned signals, and females base their choice of mates entirely on these signals. The use of synthetic, computer- generated sounds in playback experiments will be used to identify the exact acoustic criteria extracted from these signals by females from different populations throughout the range of the complex. A major selective factor that may shape differences between populations is the complexity of the acoustic community, and female selectivity will thus be compared between populations where two, genetically incompatible members of the complex co- exist with populations in which only a single species occurs. Further experiments will explore the effects of increasing acoustic complexity (background noise and number of competing signalers) on intrapopulational mate choice. Finally, the gray treefrog complex consists of three lineages of tetraploids that have acoustic signals with similar acoustic structures. Because these lineages are thought to have arisen independently and in one generation by autopolyploidy (doubling of chromosome numbers caused by environment factors), the question of how they achieved behavioral isolation from their diploid ancestors arises. The hypothesis that the changes in cell size and number that accompanies autopolyploidy have behaviorally important effects on call structure, female-choice criteria, or both will be tested by creating artificial polyploids from the cold-shocked eggs of diploid individuals.