Benjamin Simons

From wave-like excitations of atoms in solids to dissipationless transport in superfluids, complex interactions at the microscale often translate into new emergent behaviours at the macroscale. A triumph of 20th Century physics was to understand how such collective phenomena can be encapsulated within the framework of minimal “coarse-grained”, hydrodynamic theories. As well as being fundamental in their own right, such phenomenologies provide a common mathematical language to understand cooperative behaviours across a broad range of physical contexts. But does this approach translate to biology? In contrast to physics, the focus in biology is on evolved systems driven far from equilibrium –a hallmark of living systems– where the applicability of such approaches is not guaranteed. Yet, by placing emphasis on the behaviour of statistical ensembles, be they molecules, cells, tissues or communities, concepts from physics can provide a language to address emergent phenomena in biological systems. Here, using case studies from gene silencing memory, stem cell biology and the morphogenesis of branching tissues, I will show how approaches from statistical physics and dynamical systems can provide mechanistic insights into biological processes, from the molecular and cellular to the tissue and organ scale.