Evolution and Ecology Research Centre, The University of New South Wales, Kensington, New South Wales 2052, Australia.
Philos Trans R Soc Lond B Biol Sci. 2012 Jul 5;367(1597):1811-28. doi: 10.1098/rstb.2011.0215.
Complex social communication is expected to evolve whenever animals engage in many and varied social interactions; that is, sociality should promote communicative complexity. Yet, informal comparisons among phylogenetically independent taxonomic groups seem to cast doubt on the putative role of social factors in the evolution of complex communication. Here, we provide a formal test of the sociality hypothesis alongside alternative explanations for the evolution of communicative complexity. We compiled data documenting variations in signal complexity among closely related species for several case study groups--ants, frogs, lizards and birds--and used new phylogenetic methods to investigate the factors underlying communication evolution. Social factors were only implicated in the evolution of complex visual signals in lizards. Ecology, and to some degree allometry, were most likely explanations for complexity in the vocal signals of frogs (ecology) and birds (ecology and allometry). There was some evidence for adaptive evolution in the pheromone complexity of ants, although no compelling selection pressure was identified. For most taxa, phylogenetic null models were consistently ranked above adaptive models and, for some taxa, signal complexity seems to have accumulated in species via incremental or random changes over long periods of evolutionary time. Becoming social presumably leads to the origin of social communication in animals, but its subsequent influence on the trajectory of signal evolution has been neither clear-cut nor general among taxonomic groups.
复杂的社会交流有望在动物进行多种多样的社会互动时进化；也就是说，社会性应该促进交际的复杂性。然而，对来自不同进化分支的分类群进行的非正式比较，似乎对社会因素在复杂交流进化中的潜在作用提出了质疑。在这里，我们在对交际复杂性的进化进行替代解释的同时，对社会性假说进行了正式的检验。我们收集了有关几个案例研究群体（蚂蚁、青蛙、蜥蜴和鸟类）中信号复杂性变化的资料，这些资料记录了密切相关物种之间的信号复杂性变化，并使用新的系统发育方法研究了沟通进化背后的因素。社会因素仅与蜥蜴复杂视觉信号的进化有关。在青蛙（生态学）和鸟类（生态学和体型）的发声信号中，生态学和在某种程度上体型大小可能是复杂性的主要解释因素。在蚂蚁的信息素复杂性方面，有一些证据表明存在适应性进化，尽管没有确定明确的选择压力。对于大多数分类群，系统发育零模型始终优于适应性模型，并且对于某些分类群，信号复杂性似乎通过长期进化过程中的渐进或随机变化在物种中积累。在动物中，变得社会性可能导致社会交流的起源，但它对信号进化轨迹的后续影响在分类群中既不明确也不普遍。
