Data from: Task-switching costs promote the evolution of division of labor and shifts in individuality

From microbes to humans, the success of many organisms is achieved by dividing tasks among specialized group members. The evolution of such division of labor strategies is an important aspect of the major transitions in evolution. As such, identifying specific evolutionary pressures that give rise to group-level division of labor has become a topic of major interest among biologists. To overcome the challenges associated with studying this topic in natural systems, we use actively evolving populations of digital organisms, which provide a unique perspective on the de novo evolution of division of labor in an open-ended system. We provide experimental results that address a fundamental question regarding these selective pressures: Does the ability to improve group efficiency through the reduction of task-switching costs promote the evolution of division of labor? Our results demonstrate that as task-switching costs rise, groups increasingly evolve division of labor strategies. We analyze the mechanisms by which organisms coordinate their roles and discover strategies with striking biological parallels, including communication, spatial patterning, and task-partitioning behaviors. In many cases, under high task-switching costs, individuals cease to be able to perform tasks in isolation, instead requiring the context of other group members. The simultaneous loss of functionality at a lower level and emergence of new functionality at a higher level indicates that task-switching costs may drive both the evolution of division of labor and also the loss of lower-level autonomy, which are both key components of major transitions in evolution.

从微生物到人类，诸多生物的成功均依托于特化群体成员间的任务分工。这类任务分工策略的演化，乃是演化重大过渡事件的重要组成部分。正因如此，探明驱动群体层面任务分工产生的具体演化压力，已成为生物学家高度关注的研究课题。为克服在自然系统中研究该主题所面临的诸多挑战，我们采用了持续演化的数字生物种群，其为开放系统中任务分工的从头演化提供了独特的研究视角。我们通过实验结果解答了关于这些选择压力的一个核心问题：通过降低任务切换成本以提升群体效率的能力，是否会推动任务分工的演化？实验结果表明，随着任务切换成本升高，群体愈发倾向于演化出任务分工策略。我们分析了生物协调自身角色的机制，并发现了与生物学现象高度相似的策略，包括通信、空间格局构建与任务分配行为。在诸多情形下，当任务切换成本较高时，个体将无法独立完成任务，转而依赖其他群体成员所处的环境。低层级功能的同时丧失与高层级新功能的涌现，表明任务切换成本可能同时推动任务分工的演化以及低层级自主性的丧失——而这二者均为演化重大过渡事件的核心组成部分。