I am a theoretical ecologist, and I use mathematical models to understand how organisms interact with each other and with their environment. I started by career as a statistical physicist, studying for a DPhil at Oxford and then working as a postdoc in Switzerland, Canada, and the UK. In 1998 I switched to biology, first as a postdoc at the University of Cambridge, followed by a faculty position at the University of Leeds. I moved to Liverpool in 2013.
Biology has been described as a science of differences, and these differences manifest themselves at many levels: species use different strategies to survive, individuals of the same species can display a wide diversity of traits and life histories, and populations change over space and time. I am particularly interested in the ways that these different kinds of heterogeneity affect how species coexist, invade, and evolve.
Much of my research focuses on building mathematical approaches that can take account of this heterogeneity without ending up with models that are hopelessly complicated. For example, to describe a population exactly one would have to know the characteristics of every individual in the system, but in many cases good approximations can be derived by describing the distribution of their attributes using a random process. For some years now I have been developing methods for quantifying the impact of spatial structure, stochasticity (noise), and other sorts of heterogeneity, which can be applied to the dynamics of a very wide range of systems of interacting populations.