Emergence of Collective Behaviour in Motile Marine Organisms

运动实体的集体动力学是“活动物质”领域的主要领域之一，在这一领域中，从最小尺度的能量输入中出现大范围的协调。这一广阔的研究领域仍然开放，其双重目标包括了解协调运动出现背后的物理机制，以及发展能够捕捉到这种物理现象的偏微分方程式。因此，这项工作正好符合EPSRC的(I)生物物理和软物质、(Ii)数学生物学和(Iii)复杂性科学的研究范畴。在这个项目中，重点放在被称为动植物蠕虫的真核生物上，它们的大尺寸(毫米)和分布在世界各地的活动来源(纤毛地毯)使人们能够通过实验表征生物间相互作用的流体动力学，这些流体动力学推动形成显著的宏观循环涡旋的连贯游泳。它将包括对单个有机体游泳的实验研究，描述它们成对相互作用的新的流体动力学方法，以及解释作为有机体浓度函数的集体行为转变的新实验方法。同时，向集体行为的转变将由一个源于运动论的理论模型来描述，该理论模型考虑了个人和成对的动态。

Collective dynamics of motile entities is one of the primary areas within the field of 'active matter', where large-scale coordination emerges from energy input at the smallest scales. The twin goals of this broad area of research, still open, involve understanding the physical mechanisms behind the emergence of coordinated motion, and the development of partial differential equations that capture that physics. As such, the work fits squarely within the EPSRC researchareas of (i) Biological Physics and Soft Matter, (ii) Mathematical Biology, and (iii) Complexity Science. In this project, the focus is on eukaryotic organisms known as plant-animal worms, whose large size (millimetres) and distributedsource of motility (ciliary carpets) enable experimental characterisation of the fluid dynamics of inter-organism interactions that drive the formation of remarkable macroscopic circulating vortices of coherent swimming. It will involve experimental investigations of the swimming of individual organisms, novel methods of fluid dynamics to characterise their pairwise interactions, and new experimental methods to elucidate the transition to collective behaviour as a functionof the concentration of organisms. Concurrently, the transition to collective behaviour will be described by a theoretical model derived from kinetic theory, accounting for those individual and pairwise dynamics.