Guillaume Achaz 12th March 2014

On Wednesday 12th March, Dr Guillaume Achaz, Atelier de BioInformatique, will give the talk “Epistatic constraints in evolution, theory and practice.”

Building 53 Room 4025, Highfield Campus, 4pm. All welcome. Refreshments served after the talk.

Abstract:

How constrained is life’s evolution? Can mutations occur in any order? What fundamental processes dictate how evolution can proceed? I will discuss some work on experimental and model fitness landscapes that aims at understanding what is the minimum set of rules that are needed to characterize constraints in evolving genetic systems. The work tries to maximize the fit between real biological data and theroretical models. In particular, I will illustrate how both data analysis and model building can feed each other and may utlimately converge. This project aims at taking a step further in our comprehension of the life as it was, is and will be.

Andrew Philippides 27th Nov 2013

On Wednesday 27th November, Dr Andrew Philippides, University of Sussex, will give the photo of Andy Philippidestalk “Visual route navigation in ants: a situated and embodied approach”

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

Abstract:

The use of visual information for navigation appears to be a universal strategy for sighted animals. One particular group of expert navigators are the ants. The broad cross-disciplinary interest in studies of ant navigation is in part due to their small brains; biomimetic engineers take inspiration from elegant and parsimonious control solutions, while biologists look for a description of the minimal cognitive requirements for complex spatial behaviours. We also take an interdisciplinary approach to studying visual guided navigation of ants where we emphasise tenets familiar to Adaptive Systems practitioners; to get a full understanding of complex behaviour and how it emerges from the interaction of sensory system, body and environment, you must study natural behaviour in the natural habitat.

Behavioural experiments and natural image statistics show that visual navigation need not depend on the recognition of objects. Modelling suggests how simple behavioural routines enable navigation using familiarity detection rather than explicit recall. This leads to a new navigation algorithm which successfully navigates visually complex worlds, with routes that show many characteristics of desert ants. In particular, we show that robust navigation can be achieved with simple computation, after a single training run without specifying when or what to learn. Further, the model replicates data from classic ant navigation experiments. As such, our model represents the only detailed and complete model of insect route guidance to date. I will end by discussing applications to robotic navigation.

Attila Lázár 13th Nov 2013

On Wednesday 13th November, Dr Attila Lázár, University of Southampton, will give a jointattila_lazar.jpg_SIA - JPG - Fit to Width_144_true CS4 / Sustainability Science Southampton talk “The complex challenge of achieving sustainable livelihoods in coastal Bangladesh”

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

Abstract:

Delta environments support 500 million people globally, often at very high densities (often > 1000 people per sq. km.) reflecting high agricultural productivity and more broadly high availability of ecosystem services. The future of these environments is uncertain due to multiple threats such as global climate change (e.g. sea-level rise), upstream catchment changes (e.g. new big dams) and local changes (e.g. pumping of groundwater inducing subsidence and salinisation). Hence deltas are complex social-environmental systems where the continuum of change is driven by multiple interacting factors operating at different temporal and spatial scales. The ESPA Delta project is exploring these issues through the lens of ecosystem services and poverty alleviation in the Ganges-Brahmaputra-Meghna Delta case study. The project comprises more than 20 collaborating institutions in UK, Bangladesh, India and China and wide-ranging expertise from governance, to social science to natural science and engineering. The overarching goal is to understand the dynamic link between human well-being and ecosystem services in a changing environment. In addition, the research is conducted in a participatory manner with policy stakeholders (national and local levels) and the ultimate aim is to provide tools and insights which support national and sub-national planning. Hence the diverse strands of the project need to be integrated in a meaningful way, including allowing for the complex interactions and feedback mechanisms which can occur. This presentation provides a overview of the ESPA Deltas project and how it explores concepts in system dynamics and modelling (meta-models and emulators) to provide policy relevant insights about this complex system.

CS4 Future Talk: Francisco Santos

fcsOn Wednesday 26th June May, Dr Francisco Santos, , Lisbon, will give the CS4 talk “Climate Policy: How to Cooperate in an Uncertain World”

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

Abstract:

“The welfare of our planet stands as a perfect example of what scientists commonly refer to as public goods — a global good from which everyone profits, whether or not they contribute to maintain it. Indeed, reducing the effects of global warming has been described as one of the greatest public goods problems (or “games”) we humans face, and the one we cannot afford to lose. Unfortunately, individuals, regions or nations may opt to be “free riders”, hoping to benefit from the efforts of others while choosing not to make any effort themselves. Cooperation problems faced by humans often share this setting, in which the immediate advantage of free riding drives the population into the “tragedy of the commons”, the ultimate limit of widespread defection. Moreover, nations and their leaders seek a collective goal that is shadowed by the uncertainty of its achievement.

In this seminar, I will discuss an evolutionary dynamics approach to a broad class of cooperation problems in which attempting to minimize future losses turns the risk of failure into a central issue in individual decisions. Our results suggest that global coordination for a common good should be attempted by segmenting tasks in many small to medium sized groups in which perception of risk is high and achievement of goals involves stringent requirements (whose meaning I will make precise). Moreover, whenever the perception of risk is low — as it is presently the case — we find that a polycentric approach involving multiple institutions is more effective than that associated with a single, global one, indicating that a bottom-up approach, setup at a local scale, provides a better ground on which to attempt a solution for such a complex and global dilemma. Finally, we show that, if one takes into consideration that individuals are interwoven in complex political networks, the chances for global coordination in an overall cooperating state are further enhanced.”

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.”