Department of Zoology, University of Cambridge, Downing Street, CB2 3EJ, Cambridge, UK.
Ecol Lett. 2018 Aug;21(8):1129-1134. doi: 10.1111/ele.13079. Epub 2018 May 25.
Studies of eusocial invertebrates regard complex societies as those where there is a clear division of labour and extensive cooperation between breeders and helpers. In contrast, studies of social mammals identify complex societies as those where differentiated social relationships influence access to resources and reproductive opportunities. We show here that, while traits associated with social complexity of the first kind occur in social mammals that live in groups composed of close relatives, traits associated with the complexity of social relationships occur where average kinship between female group members is low. These differences in the form of social complexity appear to be associated with variation in brain size and probably reflect contrasts in the extent of conflicts of interest between group members. Our results emphasise the limitations of any unitary concept of social complexity and show that variation in average kinship between group members has far-reaching consequences for animal societies.
社会性无脊椎动物的研究将复杂社会定义为那些在繁殖者和帮手之间存在明显分工和广泛合作的社会。相比之下，社会性哺乳动物的研究将复杂社会定义为那些分化的社会关系影响资源获取和生殖机会的社会。我们在这里表明，虽然与第一类社会复杂性相关的特征出现在生活在由近亲组成的群体中的社会性哺乳动物中，但与社会关系复杂性相关的特征出现在雌性群体成员之间平均亲缘关系较低的地方。这种社会复杂性形式的差异似乎与大脑大小的变化有关，可能反映了群体成员之间利益冲突的程度不同。我们的研究结果强调了任何单一的社会复杂性概念的局限性，并表明群体成员之间平均亲缘关系的变化对动物社会有着深远的影响。
