Cantor Maurício, Shoemaker Lauren G, Cabral Reniel B, Flores César O, Varga Melinda, Whitehead Hal
Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, Canada, NS B3H 4J1.
Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, UCB 334, Ramaley Hall, Boulder, Colorado 80309, USA.
Nat Commun. 2015 Sep 8;6:8091. doi: 10.1038/ncomms9091.
Multilevel societies, containing hierarchically nested social levels, are remarkable social structures whose origins are unclear. The social relationships of sperm whales are organized in a multilevel society with an upper level composed of clans of individuals communicating using similar patterns of clicks (codas). Using agent-based models informed by an 18-year empirical study, we show that clans are unlikely products of stochastic processes (genetic or cultural drift) but likely originate from cultural transmission via biased social learning of codas. Distinct clusters of individuals with similar acoustic repertoires, mirroring the empirical clans, emerge when whales learn preferentially the most common codas (conformism) from behaviourally similar individuals (homophily). Cultural transmission seems key in the partitioning of sperm whales into sympatric clans. These findings suggest that processes similar to those that generate complex human cultures could not only be at play in non-human societies but also create multilevel social structures in the wild.
多层次社会包含层次嵌套的社会层级，是一种起源不明的非凡社会结构。抹香鲸的社会关系以多层次社会的形式组织起来，其上层由使用相似滴答声模式（尾声）进行交流的个体群体组成。基于一项为期18年的实证研究构建基于主体的模型，我们发现群体不太可能是随机过程（基因或文化漂变）的产物，而可能源于通过对尾声的偏向性社会学习进行的文化传播。当鲸鱼优先从行为相似的个体（同类相吸）那里学习最常见的尾声（从众）时，就会出现具有相似声学 repertoire 的不同个体集群，这与实证研究中的群体情况相符。文化传播似乎是将抹香鲸划分为同域群体的关键因素。这些发现表明，类似于产生复杂人类文化的过程不仅可能在非人类社会中起作用，还能在野外创造出多层次社会结构。
