CS4 Future Talk: Nathaniel Virgo

me2On Wednesday 29th May, Dr Nathaniel Virgo, University of Tokyo, will give the CS4 talk “Gaia before life: Autocatalysis and the Prebiotic Ecosystem”

Building 53 Room 4025, Highfield Campus, 4-5pm. Refreshments served after the talk.

Abstract:
“Today’s Earth is populated by organisms that extract energy from their surroundings, in the form of sunlight or chemical energy. In so doing they affect the chemistry of their environment. The energy they extract flows through the system via predation and nutrient recycling, eventually being dissipated as heat. The resulting ecological and biogeochemical feedbacks lead to homeostatic self-regulation, both locally and on a global scale.

Some previous authors have suggested that these phenomena are not specific to biology and can occur in purely chemical systems, when held out of equilibrium by a source of energy. In this talk I will present some progress toward understanding how such abiotic ecosystems can form, and how they might give rise to complex chemistry and perhaps ultimately life. I will conclude that we should see Gaia not as a consequence of the biosphere, but as the context in which it first arose.

This work consists of two main strands. The first is understanding how autocatalysis (roughly, molecular self-reproduction) can arise in a system containing only relatively simple molecules that cannot act as enzymes; the second is understanding how autocatalytic systems behave in a spatial context once ‘ecological’ feedbacks are added, such as a limitation in the energy or nutrient supply. I will present modelling results suggesting that autocatalytic cycles can arise more easily in chemical systems than previously thought, and that ecological-type feedbacks can “tune” a system’s parameters into the range where complex spatial patterning occurs.

In addition to theoretical modelling work, we plan to test these ideas experimentally using the polymerisation of hydrogen cyanide (HCN) as the energy source, and I will briefly present our progress toward such experiment and the challenges it is likely to present.”

CS4 Future Talk: Matthew Turner

On Wednesday 15th May, Professor Matthew Turner, University of Warwick, will give the CS4 talk “Social Fluids”mstvelvet5

Building 53 Room 4025, Highfield Campus, 4-5pm. Refreshments served after the talk.

Abstract

“Bird flocks, insect swarms and fish shoals resemble fluids made up of many individuals in which the controlling interactions are social rather than physical in character. It may be that these animal systems tell us something about human societies or inform developments in swarm robotics. Some progress has been made recently on reverse-engineering candidate models for the interactions between animals that are local in space, either in a metric-based or topological sense. A question that has been largely overlooked is whether the interactions should be expected to be local in the first place. I will present evidence that they must have a non-local character and, furthermore, that there is a natural choice for this that is consistent with the cognitive limitations of animal vision. This leads us to propose a non-local hybrid-projection model. We use this model to make predictions about the global character of the swarm and present experimental data on bird flocks that confirm these predictions. Finally, I will discuss how these models are naturally associated with evolutionary fitness.”