Work

PhD

Evolutionary game theory models for the origins of agriculture and the rise of social inequality.

Supervised by Professor Mark Thomas (Research Department of Genetics, Evolution and Environment), Dr Peter Bentley (Department of Computer Science) and Professor Stephen Shennan (Institute of Archaeology).

The origin of agriculture in southwest Asia at the end of the last Ice Age and its subsequent spread as the main form of human subsistence was one of the most important transformations in human evolution and continues to have major consequences today for many aspects of human health and ways of life. Recent work has challenged behavioural ecology explanations that have seen it as the endpoint of a long-term expansion of human diet breadth to incorporate lower-ranked resources with increased processing costs. Instead Bowles and Choi have developed an evolutionary game theory model of the returns from hunting and gathering versus farming in the context of different systems of property rights by comparing the payoffs of three different strategies – Sharer, Civic and Bourgeois – in relation to the different subsistence systems and the returns expected from them in different climatic conditions. However, there are weaknesses in the Bowles-Choi model.

The aim of the project is to develop alternative evolutionary game theory models for the origins of agriculture and go on to model the payoffs to different property inheritance systems and their effects on inequality.

MRes Summer Project

An Agent-based Model for Pain Expression

Supervised by Dr Peter Bentley (Department of Computer Science) and Dr Amanda Williams (Department of Clinical, Educational & Health Psychology).

Pain motivates escape, healing and recuperation. If pain can be effectively communicated in the presence of caregivers then these objectives can be achieved sooner. These aims can further be aided if pain behaviour can be suppressed in the presence of antagonists, where vulnerability can be taken advantage of. Hence, in certain social situations the amount of tissue damage can be uncorrelated to the degree of pain behaviour.

By considering the interactions of heterogeneous individuals in a range of different environments the conditions for which pain expression is favourable can be established. This project aims to achieve such a goal by developing an agent-based model where agents can either express or suppress pain if randomly injured, and aid or ignore the pain expression of others. Interactions between agents will incur costs and benefits, these will affect which agents are chosen for interactions, which agents will "die" and which agents will be selected for parenthood. Hence, the proportions of strategies in an agent population found using different parameter values will reflect the conditions needed for pain expression to prevail.

The results found are intuitive and successfully simulate the co-occurrence of pain expression with its ability to be detected and helped by others. Furthermore, results predict that social support motivates expression and an increase in social threat provokes less expression; results which have been observed experimentally.

MRes Case Presentations

Female Choosiness and Tracking Approaches in Drosophila

Supervised by Dr. Joerg Albert and Prof. Andrew Pomiankowski

During courtship in Drosophila species-specific auditory information is signalled to the female via the males courtship song. This sexually selected behaviour is interesting from an evolutionary and an anatomical level. This report considers quantifying female choosiness in Drosophila with the goal to understand courting behaviour more comprehensively. Two methods for tracking flies using Wolfram Mathematica 9 were developed and their application outlined.

Neural Representation of Spatial Location

Supervised by Prof. Neil Burgess, Prof. John O'Keefe and Dr Francesca Cacucci

Place, boundary vector, head-direction and grid cells located in the hippocampus provide neural representations of space. This representation acts as a scaffold for learning about the environment, and develops independently of spatial experience. Investigating the properties of spatial firings in hippocampal cells from young animals may yield insights into how this scaffold emerges and develops.

Measuring Semantic Ambiguity

Supervised by Prof. Gabriella Vigliocco, Dr Stefan Frank and Dr Sebastian Riedel

The reading time for a word varies with how ambiguous it is. Furthermore, the time it takes to read an ambiguous word is dependent on whether it is in context or not. Using results from latent semantic analysis and the lexical database WordNet, four ways of measuring the degree of semantic ambiguity were developed. In-context and out-of-context reading times for 190 words were used to test the relationship between ambiguity and reading time. Our results show that ambiguous words take less time to read both in-context and out-of-context.

Other work

Interspecific Kleptoparasitism, submitted for my University of Bath MSc dissertation.

Supervised by Prof. Nick Britton

Although interspecific kleptoparasitism is widespread, theoretical models of kleptoparasitism focus on the intraspecific case. This project develops a game-theoretic model of the behavioural decisions of a host species exploited by a kleptoparasite. The case where the host species can choose to fight to retain its food or immediately surrender its food is considered and the model is used to determine the optimal host strategy for different ecological conditions. This model is a modification of published intraspecific models, in particular that of Ruxton & Moody (1997).