Behavioural variation among workers promotes feed-forward loops in a simulated insect colony

Coordinated responses in eusocial insect colonies arise from worker interaction networks that enable collective processing of ecologically relevant information. Previous studies have detected a structural motif in these networks known as the feed-forward loop, which functions to process information in other biological regulatory networks (e.g., transcriptional networks). However, the processes that generate feed-forward loops among workers and the consequences for information flow within the colony remain largely unexplored. We constructed an agent-based model to investigate how individual variation in activity and movement shaped production of feed-forward loops in a simulated insect colony. We hypothesised that individual variation along these axes would generate feed-forward loops by driving variation in interaction frequency among workers. We found that among-individual variation in activity drove overrepresentation of feed-forward loops in the interaction networks by determining the directionality of interactions. However, despite previous work linking feed-forward loops with efficient information transfer, activity variation did not promote faster or more efficient information flow, thus providing no support for the hypothesis that feed-forward loops reflect selection for enhanced collective functioning. Conversely, individual variation in movement trajectory, despite playing no role in generating feed-forward loops, promoted fast and efficient information flow by linking together unconnected regions of the nest.真社会性昆虫群体的协同响应源于工虫互作网络，该网络可实现对生态相关信息的集体加工处理。既往研究已在这类网络中发现一种被称为前馈环（feed-forward loop）的结构基序，该基序在其他生物调控网络（如转录调控网络）中负责信息处理功能。然而，关于工虫间形成前馈环的具体过程，以及该过程对群体内信息流动的影响，目前仍鲜有研究涉足。我们构建了基于智能体的模型（agent-based model），以探究活动水平与移动模式的个体差异如何在模拟昆虫群体中影响前馈环的形成。我们提出假说：上述两类特征的个体差异会通过改变工虫间的互作频率，进而催生前馈环的形成。研究结果显示，工虫活动水平的个体差异通过决定互作的方向性，使得互作网络中的前馈环出现过度富集现象。尽管既往研究将前馈环与高效信息传递相挂钩，但我们的研究发现，活动水平的个体差异并未提升信息流动的速度与效率，因此无法支持“前馈环反映了对增强群体功能的选择压力”这一假说。与之相反，尽管移动轨迹的个体差异并未参与前馈环的形成，但它通过连接蚁巢内互不连通的区域，提升了信息流动的速度与效率。