Data from: Testing the reproductive groundplan hypothesis in ants (Hymenoptera: Formicidae)

The evolution of complex societies with obligate reproductive division of labour represents one of the major transitions in evolution. In such societies, functionally sterile individuals (workers) perform many of fitness-relevant behaviours including allomaternal ones, without getting any direct fitness benefits. The question of how such worker division of labour has evolved remains controversial. The reproductive groundplan hypothesis (RGPH) offers a powerful proximate explanation for this evolutionary leap. The RGPH argues that the conserved genetic and endocrinological networks regulating fitness relevant behaviour (e g. foraging and brood care) in their solitary ancestors have become decoupled from actual reproduction in the worker caste and now generate worker behavioural phenotypes. However, the empirical support for this hypothesis remains limited to a handful of species making its general validity uncertain. In this study we combine data from the literature with targeted sampling of key species and apply phylogenetically controlled comparative analysis to investigate if the key prediction of the RGPH, namely an association between allomaternal behaviour and a allomaternal physiological state holds in the largest and most species-rich clade of social insects, the ants. Our findings clearly support the RPGH as a general framework to understand the evolution of the worker caste and shed light on one of the major transition in evolutionary history.

具有专性生殖分工的复杂社会的演化，代表了演化历程中的重大转型之一。在这类社会中，功能上不育的个体（工蚁）会执行诸多与适合度相关的行为——包括异亲抚育行为（allomaternal behaviour），却无法获得任何直接的适合度收益。这类工蚁分工的演化机制至今仍存在争议。生殖蓝图假说（reproductive groundplan hypothesis, RGPH）为这一演化跃迁提供了强有力的近因解释。该假说认为，独居祖先体内调控与适合度相关行为（例如觅食与育幼）的保守遗传与内分泌网络，在工蚁阶级中已脱离了实际的生殖过程，并由此产生了工蚁的行为表型。然而，目前该假说的实证支持仅局限于少数物种，使其普遍有效性尚未明确。本研究将文献数据与关键类群的针对性采样相结合，采用系统发育控制比较分析方法，旨在检验RGPH的核心预测——即异亲抚育行为与异亲生理状态之间的关联——是否在物种最多样化的社会性昆虫支系——蚁类中成立。本研究结果明确支持RGPH作为阐释工蚁阶级演化的通用框架，并为演化历史上的重大转型之一提供了新的认知。