The price of insurance: costs and benefits of worker production in a facultatively social bee

Kin selection theory is foundational in helping to explain the evolution of sociality; however, the degree to which indirect fitness benefits may underlie helping behavior in species of early stage sociality has received relatively little empirical attention. Facultatively social bees, which demonstrate multiple forms of social organization, provide prime systems in which to empirically test hypotheses regarding the evolutionary origins of sociality. The subsocial small carpenter bee, Ceratina calcarata, may establish a social nest by manipulating brood provisions to rear a worker daughter, which then assists in critical late-season alloparental care. Here, we combine nest demographic and behavioral data with genetic relatedness estimates to calculate the relative inclusive fitness of both subsocial and social reproductive strategies in C. calcarata. Social mothers benefit from improved likelihood of brood survivorship and have higher fitness than subsocial mothers. Worker daughters hav...亲缘选择理论（Kin selection theory）是阐释社会性演化的奠基性理论；然而，间接适合度收益在多大程度上支撑早期社会性物种种群的互助行为，相关实证研究却相对匮乏。兼性社会性蜂类兼具多种社会组织形式，是开展社会性演化起源相关假说实证检验的理想研究体系。亚社会性的矮小芦蜂（Ceratina calcarata）可通过调控幼虫食物培育出职虫雌性后代，该后代会在季末关键阶段协助开展异亲抚育工作。本研究结合巢群统计与行为数据及遗传亲缘度估算结果，计算了矮小芦蜂中亚社会性与社会性两种繁殖策略的相对广义适合度（inclusive fitness）。社会性蜂后的子代存活概率得以提升，其适合度也高于亚社会性蜂后；职虫雌性后代则……