Climate, density-dependence and population dynamics: towards an integrated perspective

Supervisors: Dr Dylan Childs (primary)
Dr Andrew Beckerman

Key words: climate change, population biology, Soay sheep, evolution, life history, modelling

Ecologists have long been fascinated by the dynamics of natural populations. The changes in abundance that we observe result from a complex interplay between environmental change, variation in resource availability via density dependent feedbacks, and the physiological structure of the population. It has become clear that such processes are also important for understanding not only ecology, but also natural selection: ecology provides the theatre in which evolution plays out. Since they are difficult to study directly, much of our understanding of these complex processes comes from the development of models of well-studied natural populations. Such models make a number of simplifying assumptions to keep them tractable. For example, they typically assume that each individual has the same density dependent impact on a population regardless of its own state, or that the environment varies over a single time scale. We know that these assumptions are not realistic, but we still don’t yet know if they matter. The central question of this PhD is: does improving the way we represent environmental (e.g. climate) and density-dependent processes substantively change our predictions about ecological and evolutionary processes?

This project will use data from the long-term study of Soay sheep on St Kilda, Scotland. The student will use this dataset to develop novel ways of modelling the environmentally driven, density-dependent population dynamics of Soay sheep. These models will be used to understand how population dynamics and natural selection change under different regimes of climate variation. The student will have an opportunity to visit St Kilda during at least once and will work closely with our collaborators in Oxford and St Andrews.

To apply, please complete an online application form which can be found at www.shef.ac.uk/postgraduate/research/apply/applying
The closing date is 15th January 2013