Data from: Family based guilds in the ant Pachycondyla inversa

High relatedness promotes the evolution of sociality because potentially costly cooperative behaviours are directed towards kin. However, societies, such as those of social insects, also benefit from genetic diversity, e.g. through enhanced disease resistance and division of labour. Effects of genetic diversity have been investigated in a few complex eusocial species. Here, we show that genetically based division of labour may also be important in ‘simple societies’, with fewer individuals and limited morphological caste differentiation. The ponerine ant Pachycondyla inversa has small colonies, headed by several unrelated queens. We show that nest-mate workers from different matrilines engage in different tasks, have distinct chemical profiles and associate preferentially with kin in the nest, while queens and brood stay together. This suggests that genetically based division of labour may precede the evolution of complex eusociality and facilitate the existence of low relatedness societies functioning as associations of distinct families that mutually benefit from group living.

高亲缘度（high relatedness）可推动社会性演化，因为具有潜在适合度代价的合作行为会定向指向亲属。然而，诸如社会性昆虫类群的社会系统，也可从遗传多样性中获益，例如通过提升抗病性与劳动分工实现收益。目前已有少量研究针对复杂真社会性（eusocial）物种探讨了遗传多样性的效应。本研究表明，基于遗传基础的劳动分工，在个体数量较少、形态品级分化有限的“简单社会”中同样具有重要意义。猛蚁亚科（ponerine）的反曲厚结猛蚁（Pachycondyla inversa）种群规模较小，由多只无亲缘关系的蚁后统领。本研究发现，来自不同母系谱系（matrilines）的同巢工蚁会承担不同的任务，拥有独特的化学特征谱，并在巢内优先与亲属聚集，而蚁后与幼虫则始终共处。这表明，基于遗传基础的劳动分工可能先于复杂真社会性（eusociality）演化出现，并助力低亲缘度社会的存续——这类社会由多个独特家族组成，群体生活可使各方均获益。