Baeckens Simon, Whiting Martin J
Functional Morphology Laboratory, Department of Biology, University of Antwerp, 2610 Wilrijk, Belgium.
Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia.
Proc Biol Sci. 2021 Feb 24;288(1945):20202438. doi: 10.1098/rspb.2020.2438. Epub 2021 Feb 17.
The evolution of sociality and traits that correlate with, or predict, sociality, have been the focus of considerable recent study. In order to reduce the social conflict that ultimately comes with group living, and foster social tolerance, individuals need reliable information about group members and potential rivals. Chemical signals are one such source of information and are widely used in many animal taxa, including lizards. Here, we take a phylogenetic comparative approach to test the hypothesis that social grouping correlates with investment in chemical signalling. We used the presence of epidermal glands as a proxy of chemical investment and considered social grouping as the occurrence of social groups containing both adults and juveniles. Based on a dataset of 911 lizard species, our models strongly supported correlated evolution between social grouping and chemical signalling glands. The rate of transition towards social grouping from a background of 'epidermal glands present' was an order of a magnitude higher than from a background of 'no epidermal glands'. Our results highlight the potential importance of chemical signalling during the evolution of sociality and the need for more focused studies on the role of chemical communication in facilitating information transfer about individual and group identity, and ameliorating social conflict.
社会性的演变以及与社会性相关或可预测社会性的特征，一直是近期大量研究的焦点。为了减少群体生活最终带来的社会冲突，并促进社会容忍度，个体需要有关群体成员和潜在对手的可靠信息。化学信号就是这样一种信息来源，并且在包括蜥蜴在内的许多动物类群中广泛使用。在此，我们采用系统发育比较方法来检验社会群体形成与化学信号传递投入相关的假说。我们将表皮腺的存在作为化学信号传递投入的指标，并将社会群体形成视为包含成年个体和幼年个体的社会群体的出现。基于911种蜥蜴物种的数据集，我们的模型有力地支持了社会群体形成与化学信号传递腺体之间的协同进化。从“存在表皮腺”背景向社会群体形成转变的速率比从“无表皮腺”背景转变的速率高一个数量级。我们的研究结果凸显了化学信号传递在社会性进化过程中的潜在重要性，以及需要更有针对性地研究化学通讯在促进关于个体和群体身份的信息传递以及缓解社会冲突方面的作用。
