Dr Robyn Araujo

Internal Models and the ‘Rules of Life’: Universal Robustness-Promoting Structures in Biological Networks

Although all of nature is subject to the laws of physics and chemistry, the notion of purpose or ‘function’, differentiates biology from other natural sciences. In particular, evolutionary selection for function has given rise to vast and elaborate networks of interacting molecules within each living cell, comprising mostly proteins, which allow cells to interpret their external environments, make decisions, and orchestrate complex responses. These signalling networks are now recognised to be a rich source of fascinating mathematical problems.

In this talk, I will discuss the search for fundamental design principles in complex cellular networks in the context of a ubiquitously-observed phenomenon known as Robust Perfect Adaptation (RPA). We have recently discovered that all RPA-capable collections of interacting molecules are able to compute integrals by exploiting special structural constraints on their underlying chemical reactions, thereby implementing the well-established engineering strategy known as integral control. We have also suggested a resolution to the complexity-robustness paradox through the discovery that RPA-capable networks must be decomposable into topological basis modules with well-defined architectures. This newly-discovered modularisation, and the remarkable computational potential of self-organising molecular networks, has important implications for evolutionary biology, embryology and development, cancer research, and drug development.