I am interested in population biology (population dynamics, community ecology, evolutionary ecology). Research in the group focuses on a wide range of questions such as the population and evolutionary dynamics of life history strategies (e.g. the evolution of longevity), the role of spatial structure on shared enemy and competing enemy interactions, the effects of enrichment on the diversity of ecological communities, the interplay between noise and dynamics in multispecies interactions and the evolution of resistance to microbes.
Many of these projects involve the development of theoretical models in conjunction with experiments or observations in the field or laboratory. To this end, we aim to test different ecological and evolutionary ecology theories by fitting relevant mathematical models to appropriate ecological experimental (or observational) data. Further details of my research interests can be found here.
I have a strong interest in science policy. From 2007 - 2016 I was a member of DEFRA's Advisory Committee on Releases to the Environment (ACRE) and more recently involved in science policy work with the European Food Safety Authority (EFSA). As part of science policy work with WHO (TDR) and FNIH, I was involved in producing a report on the efficacy, biosafety and regulations of GM Mosquitoes. In June 2014, this report, as a Guidance Framwork for testing GM Mosquitoes, was published. Through July to December 2015, I served as science advisor to the House of Lords Science and Technology committee - a report was published on GM insects.
I am involved with the academic management teams on several Doctoral Training Programmes and more information on these is available here.
Publications
The value of existing regulatory frameworks for the environmental risk assessment of agricultural pest control using gene drives
2020
|
Journal article
|
Environmental Science and Policy
The application of (synthetic) gene drives is a powerful tool to control populations of insects that are agricultural pests, vectors of diseases, or a threat to biodiversity potentially leading to the local or global eradication of a species. The potential use of gene drive organisms has triggered a heated discussion regarding their environmental impacts and regulatory oversight. However, experience exists in assessing the environmental impacts of a number of established agricultural pest control methods that require the release of living organisms, that provide high levels of area-wide control and that might be irreversible. This includes classical biological control, the sterile insect technique, the incompatible insect technique that is based on the cytoplasmic incompatibility caused by Wolbachia endosymbionts, and genetically modified insects containing self-limiting traits. The different technologies are described, the regulatory practice and experience is summarized and pathways through which these control technologies could harm valued ecosystem services are presented. With a focus on the application of gene drives in agriculture, using the invasive Drosophila suzukii (Diptera: Drosophilidae) as a case study we then discuss to what extent the existing frameworks could assist the risk assessment of insects carrying gene drives. We suggest that drawing on existing practices, experiences and legislative frameworks will provide a pragmatic and proportionate approach to evaluate the environmental risks of novel solutions based on gene drive technologies.
Sleep and intrusive memories immediately after a traumatic event in emergency department patients.
2020
|
Conference paper
|
Sleep
STUDY OBJECTIVES: Intrusive memories of psychological trauma are a core clinical feature of posttraumatic stress disorder (PTSD), and in the early period post-trauma may be a potential target for early intervention. Disrupted sleep in the weeks post-trauma is associated with later PTSD. The impact of sleep and intrusive memories immediately post-trauma, and their relation to later PTSD, is unknown. This study assessed the relationship between sleep duration on the first night following a real-life traumatic event and intrusive memories in the subsequent week, and how these might relate to PTSD symptoms at two months. METHODS: Patients (n=87) recruited in the emergency department completed a sleep and intrusive memory diary from the day of their trauma and for the subsequent week, with optional actigraphy. PTSD, anxiety and depression symptoms were assessed at one week and two months. RESULTS: A U-shaped relationship was observed between sleep duration on the first night and intrusive memories over the subsequent week: sleeping "too little" or "too much" was associated with more intrusive memories. Individuals who met CAPS PTSD criteria at two months had three times more intrusive memories in the first week immediately post-trauma than those who did not (M=28.20 vs. 9.96). Post-hoc analysis showed the absence of intrusive memories in the first week post-trauma was only observed in those who did not meet CAPS criteria for PTSD at two months. CONCLUSIONS: Monitoring intrusive memories and sleep in the first week post-trauma, using a simple diary, may help identify individuals more vulnerable to later psychopathology.
Experimental subjects do not know what we think they know.
2020
|
Journal article
|
Scientific reports
Many biological, psychological and economic experiments have been designed where an organism or individual must choose between two options that have the same expected reward but differ in the variance of reward received. In this way, designed empirical approaches have been developed for evaluating risk preferences. Here, however, we show that if the experimental subject is inferring the reward distribution (to optimize some process), they will rarely agree in finite time that the expected rewards are equal. In turn, we argue that this makes discussions of risk preferences, and indeed the motivations of behaviour, not so simple or straightforward to interpret. We use this particular experiment to highlight the serious need to consider the frame of reference of the experimental subject in studies of behaviour.
Resilience: nitrogen limitation, mycorrhiza and long-term palaeoecological plant-nutrient dynamics.
2020
|
Journal article
|
Biology letters
Ecosystem dynamics are driven by both biotic and abiotic processes, and perturbations can push ecosystems into novel dynamical regimes. Plant-plant, plant-soil and mycorrhizal associations all affect plant ecosystem dynamics; however, the direction and magnitude of these effects vary by context and their contribution to ecosystem resilience over long time periods remains unknown. Here, using a mathematical framework, we investigate the effects of plant feedbacks and mycorrhiza on plant-nutrient interactions. We show evidence for strong nutrient controlled feedbacks, moderation by mycorrhiza and influence on ecological resilience. We use this model to investigate the resilience of a longitudinal palaeoecological birch-δ15N interaction to plant-soil feedbacks and mycorrhizal associations. The birch-δ15N system demonstrated high levels of resilience. Mycorrhiza were predicted to increase resilience by supporting plant-nitrogen uptake and immobilizing excess nitrogen; in contrast, long-term enrichment in available nitrogen by plant-soil feedbacks is expected to decrease ecological resilience.
Interaction modifications lead to greater robustness than pairwise non-trophic effects in food webs.
2019
|
Journal article
|
The Journal of animal ecology
Considerable emphasis has been placed recently on the importance of incorporating non-trophic effects into our understanding of ecological networks. Interaction modifications are well-established as generating strong non-trophic impacts by modulating the strength of interspecific interactions. For simplicity and comparison with direct interactions within a network context, the consequences of interaction modifications have often been described as direct pairwise interactions. The consequences of this assumption have not been examined in non-equilibrium settings where unexpected consequences of interaction modifications are most likely. To test the distinct dynamic nature of these "higher-order" effects, we directly compare, using dynamic simulations, the robustness to extinctions under perturbation of systems where interaction modifications are either explicitly modelled or represented by corresponding equivalent pairwise non-trophic interactions. Full, multi-species representations of interaction modifications resulted in a greater robustness to extinctions compared to equivalent pairwise effects. Explanations for this increased stability despite apparent greater dynamic complexity can be found in additional routes for dynamic feedbacks. Furthermore, interaction modifications changed the relative vulnerability of species to extinction from those trophically connected close to the perturbed species towards those receiving a large number of modifications. Future empirical and theoretical research into non-trophic effects should distinguish interaction modifications from direct pairwise effects in order to maximize information about the system dynamics. Interaction modifications have the potential to shift expectations of species vulnerability based exclusively on trophic networks.
