Understanding policing as a mechanism of cheater control in cooperating bacteria

Policing occurs in insect, animal and human societies, where it evolved as a mechanism maintaining cooperation. Recently, it has been suggested that policing might even be relevant in enforcing cooperation in much simpler organisms such as bacteria. Here, we used individual‐based modelling to develop an evolutionary concept for policing in bacteria, and identify the conditions under which it can be adaptive. We modelled interactions between cooperators, producing a beneficial public good, cheaters exploiting the public good without contributing to it, and public good producing policers that secrete a toxin to selectively target cheaters. We found that toxin‐mediated policing is favoured when (i) toxins are potent and durable, (ii) cheap to produce, (iii) cell and public good diffusion is intermediate, and (iv) toxins diffuse farther than the public good. While our simulations identify the parameter space where toxin‐mediated policing can evolve, we further found that policing decays whe...

监管行为（policing）广泛存在于昆虫、动物及人类社会中，其演化成为维持群体合作的核心机制。近期已有研究指出，监管行为甚至可在细菌这类更为简单的生物体中发挥强化合作的作用。本文采用基于个体的建模方法（individual-based modelling），构建了细菌监管行为的演化理论框架，并明确了其具备适应性优势的演化条件。我们构建了三类群体的相互作用模型：产生有益公共物品（public good）的合作者、不付出任何贡献却侵占公共物品的欺骗者，以及分泌毒素以特异性靶向欺骗者的公共物品生产型监管者。研究结果表明，当满足以下条件时，毒素介导的监管行为更易被自然选择所青睐：（1）毒素具备高效性与持久性；（2）毒素的生产成本低廉；（3）细胞与公共物品的扩散程度处于中等水平；（4）毒素的扩散范围大于公共物品。尽管本研究的模拟实验明确了毒素介导监管行为可演化的参数空间，但我们进一步发现，监管行为会在……时衰退