Iwamoto Mayuko, Ueyama Daishin
Department of Mathematics and Computer Science, Interdisciplinary Graduate School of Science and Engineering, Shimane University, 1060 Nishikawatsu Matsue-city, Shimane 690-8504, Japan; Meiji Institute for Advanced Study of Mathematical Sciences (MIMS), 4-21-1 Nakano, Nakano-ku, Tokyo 164-8525, Japan.
Department of Mathematical Engineering, Faculty of Engineering, Musashino University, 3-3-3 Ariake Kohtoh-ku, Tokyo 135-8181, Japan; Meiji Institute for Advanced Study of Mathematical Sciences (MIMS), 4-21-1 Nakano, Nakano-ku, Tokyo 164-8525, Japan.
J Theor Biol. 2018 Mar 7;440:112-120. doi: 10.1016/j.jtbi.2017.12.028. Epub 2017 Dec 28.
One of the fundamental problems in biology concerns the method by which a cluster of organisms can regulate the proportion of individuals that perform various roles or modes as if each individual is aware of the overall situation without a leader. In various species, a specific ratio exists at multiple levels, from the process of cell differentiation in multicellular organisms to the situation of social dilemma in a group of human beings. This study determines a common basis for regulating collective behavior that is realized by a series of local contacts between individuals. In this theory, the most essential behavior of individuals is to change their internal mode by sharing information when in contact with others. Our numerical simulations regulate the proportion of population in two kinds of modes. Furthermore, using theoretical analysis and numerical calculations, we show that asymmetric properties in local contacts are essential for adaptive regulation in response to global information such as group size and overall density. Particle systems are crucial in allowing flexible regulation in no-leader groups, and the critical condition that eliminates overlap with other individuals (the excluded volume effect) also affects the resulting proportion at high densities. The foremost advantage of this strategy is that no global information is required for each individual, and minimal mode switching can regulate the overall proportion. This simple mechanism indicates that proportion regulation in well-organized groups in nature can be realized through and limited to local contacts, and has the potential to explain various phenomena in which microscopic individual behavior results in orderly macroscopic behavior.
生物学中的一个基本问题涉及这样一种方式，即一群生物体能够调节执行各种角色或模式的个体比例，就好像每个个体在没有领导者的情况下都知晓整体情况一样。在各种物种中，从多细胞生物中的细胞分化过程到一群人类面临的社会困境情形，在多个层面都存在特定的比例。本研究确定了一种调节集体行为的共同基础，这种集体行为是通过个体之间一系列局部接触实现的。在该理论中，个体最基本的行为是在与他人接触时通过共享信息来改变其内部模式。我们的数值模拟调节了处于两种模式下的种群比例。此外，通过理论分析和数值计算，我们表明局部接触中的不对称特性对于响应诸如群体大小和整体密度等全局信息的适应性调节至关重要。粒子系统对于在无领导者群体中实现灵活调节至关重要，并且消除与其他个体重叠的临界条件（排除体积效应）在高密度时也会影响最终的比例。这种策略的首要优势在于每个个体无需全局信息，并且最小程度的模式切换就能调节整体比例。这种简单机制表明，自然界中组织良好的群体中的比例调节可以通过局部接触并受其限制来实现，并且有潜力解释各种微观个体行为导致宏观有序行为的现象。
