The Evolution of Acoustic Signals of Frogs: Origins, Phylogenetic Information, Rates of Diversification, and Morphological Correlates

9981631 Cannatella，Hillis和Ryan拟议的研究将整合一个重要的通信系统，青蛙的广告呼叫，系统发育的方法，以解决青蛙发声的起源，与发声相关的行为特征的变化率，以及产生声音的解剖结构中喉部形状变化的相关性。 一个以前被接受的青蛙的进化史表明，最早的青蛙没有一个发达的声音信号机制。 根据最近的一个假设，最早的青蛙确实有一个发达的通信系统。 这两种替代方案将使用更完整的原始青蛙物种样本和更大的DNA序列特征样本进行测试。 有一个普遍的偏见，即行为特征比其他类别的数据更容易发生变化。 强烈的性选择对男性的声音信号的存在表明，历史的足迹可能会被快速进化的呼叫字符抹去。 因此，估计来自呼叫字符的系统发育关系将是非常不同的那些来自DNA序列。 这一观察的一般性将使用五组广泛分布在北美，中美洲和南美洲的青蛙的选定基因的完整DNA序列进行测试。

9981631Cannatella, Hillis, and RyanThe proposed research will integrate an important communication system, the advertisement call of frogs, with a phylogenetic approach in order to address the origin of frog vocalization, the rates of change in behavioral characters associated with vocalizations, and correlation of laryngeal shape change in the anatomical structures that produce the sounds. A formerly accepted phylogeny of frogs suggests that the earliest frogs did not have a well-developed acoustic signaling mechanism. According to a more recent hypothesis, the earliest frogs would indeed have had a well-developed communication system. These two alternative scenarios will be tested using more complete samples of species of the primitve frogs and larger samples of characters, from DNA sequences. There is a general bias that behavioral characters are more subject to change than other classes of data. The presence of intense sexual selection on the male vocal signal suggests that the footprint of history may be obliterated by rapid evolution of call characters. Thus, estimates of phylogenetic relationships derived from call characters will be very different from those derived from DNA sequences. The generality of this observation will be tested using complete DNA sequences of selected genes for five groups of frogs widely distributed throughout North, Central, and South America.