Filatova Olga A, Burdin Alexandr M, Hoyt Erich
Department of Vertebrate Zoology, Faculty of Biology, Moscow State University, Vorobiovy Gory, 1/12, Moscow 119991, Russia.
Behav Processes. 2013 Oct;99:34-41. doi: 10.1016/j.beproc.2013.06.008. Epub 2013 Jun 21.
The killer whale is among the few species in which cultural change accumulates over many generations, leading to cumulative cultural evolution. Killer whales have group-specific vocal repertoires which are thought to be learned rather than being genetically coded. It is supposed that divergence between vocal repertoires of sister groups increases gradually over time due to random learning mistakes and innovations. In this case, the similarity of calls across groups must be correlated with pod relatedness and, consequently, with each other. In this study we tested this prediction by comparing the patterns of call similarity between matrilines of resident killer whales from Eastern Kamchatka. We calculated the similarity of seven components from three call types across 14 matrilines. In contrast to the theoretical predictions, matrilines formed different clusters on the dendrograms made by different calls and even by different components of the same call. We suggest three possible explanations for this phenomenon. First, the lack of agreement between similarity patterns of different components may be the result of constraints in the call structure. Second, it is possible that call components change in time with different speed and/or in different directions. Third, horizontal cultural transmission of call features may occur between matrilines.
虎鲸是少数几种文化变迁历经多代积累，从而导致累积性文化进化的物种之一。虎鲸拥有特定群体的发声 repertoire，人们认为这些 repertoire 是通过学习获得的，而非由基因编码。据推测，由于随机的学习错误和创新，姐妹群体的发声 repertoire 之间的差异会随着时间逐渐增加。在这种情况下，不同群体之间叫声的相似性必然与族群关联性相关，进而相互关联。在本研究中，我们通过比较堪察加半岛东部定居虎鲸母系群体之间的叫声相似模式，对这一预测进行了检验。我们计算了 14 个母系群体中三种叫声类型的七个组成部分的相似性。与理论预测相反，在由不同叫声甚至同一叫声的不同组成部分绘制的树形图上，母系群体形成了不同的聚类。我们针对这一现象提出了三种可能的解释。第一，不同组成部分的相似性模式之间缺乏一致性，可能是叫声结构受到限制的结果。第二，叫声组成部分可能随时间以不同速度和/或不同方向发生变化。第三，叫声特征可能在母系群体之间进行横向文化传播。
