Bernadou Abel, Jeanson Raphaël
Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France.
PLoS Comput Biol. 2024 Dec 17;20(12):e1012668. doi: 10.1371/journal.pcbi.1012668. eCollection 2024 Dec.
Social insects, such as ants and bees, are known for their highly efficient and structured colonies. Division of labour, in which each member of the colony has a specific role, is considered to be one major driver of their ecological success. However, empirical evidence has accumulated showing that many workers, sometimes more than half, remain idle in insect societies. Several hypotheses have been put forward to explain these patterns, but none provides a consensual explanation. Task specialisation exploits inter-individual variations, which are mainly influenced by genetic factors beyond the control of the colony. As a result, individuals may also differ in the efficiency with which they perform tasks. In this context, we aimed to test the hypothesis that colonies generate a large number of individuals in order to recruit only the most efficient to perform tasks, at the cost of producing and maintaining a fraction of workers that remain inactive. We developed a model to explore the conditions under which variations in the scaling of workers' production and maintenance costs, along with activity costs, allow colonies to sustain a fraction of inactive workers. We sampled individual performances according to different random distributions in order to simulate the variability associated with worker efficiency. Our results show that the inactivity of part of the workforce can be beneficial for a wide range of parameters if it allows colonies to select the most efficient workers. In decentralised systems such as insect societies, we suggest that inactivity is a by-product of the random processes associated with the generation of individuals whose performance levels cannot be controlled.
社会性昆虫，如蚂蚁和蜜蜂，以其高效且结构化的群体而闻名。分工，即群体中的每个成员都有特定的角色，被认为是它们在生态上取得成功的一个主要驱动力。然而，越来越多的实证证据表明，在昆虫社会中，许多工蚁，有时超过一半，会处于闲置状态。已经提出了几种假说来解释这些模式，但没有一个能提供一个共识性的解释。任务专业化利用个体间的差异，这些差异主要受群体无法控制的遗传因素影响。因此，个体在执行任务的效率上也可能存在差异。在这种背景下，我们旨在检验这样一个假说：群体产生大量个体，目的是只招募最有效率的个体来执行任务，而代价是产生并维持一部分不活动的工蚁。我们开发了一个模型，以探索在何种条件下，工蚁生产和维持成本的缩放变化，以及活动成本，能使群体维持一部分不活动的工蚁。我们根据不同的随机分布对个体表现进行采样，以模拟与工蚁效率相关的变异性。我们的结果表明，如果一部分劳动力的不活动状态能让群体选择最有效率的工蚁，那么对于广泛的参数范围来说，这种不活动状态可能是有益的。在像昆虫社会这样的分散系统中，我们认为不活动状态是与个体产生相关的随机过程的一个副产品，而这些个体的表现水平是无法控制的。
