Projects and supervisors
Choose from the projects listed below.
Evolutionary ecology of host-parasite Interactions
50 per cent of all animal species are parasites, and how they interact with their hosts impacts ecology and evolution from individuals – e.g. host reproductive fitness – to ecosystems – e.g. parasites determine ecosystem structure and stability. We work on the interactions between parasites and social insects (mostly bumblebees, but also ants) using a range of approaches, including fieldwork, infection experiments, functional immunology, and molecular ecology. Projects available in this area include: (i) the impact and epidemiology of natural and emergent diseases, (ii) parasites in invasive species, (iii) how hosts defend themselves against parasites, and (iv) parasite phylogeography. Please contact me for further information.
Conservation: the behaviour and ecology of bumble bees
Bumblebees are a major, and attractive component of UK (and global) ecosystems, providing the essential service of pollination to wildflowers and crops. Our interests include understanding the ecological needs of bumble bees, understanding patterns of decline, and mitigating and reversing these declines. Available projects include: (i) conservation ecology of bumblebees in England, (ii) conservation of the 'flying mouse’, Bombus dahlbomii, the world’s largest bumblebee in South America, (iii) the behaviour and ecology of bumblebee queens, and (iv) the impact of pathogens on bumblebee health. Please contact me for further information.
Biology of social insects
Social insects are the ecologically dominant terrestrial animals, playing roles as major herbivores and predators, as well as providing the services of pest control, soil production and maintenance, and pollination. We are broadly interested in the biology of social insects, and are happy to support MSc projects in this area. Please look at my webpage and publications to see examples of previous work, and contact me for further information.
How does connection to nature affect science attainment in school pupils
This Masters is part of the Royal Holloway Schools’ Biodiversity Project and will investigate how working with children in their school grounds affects their connection to nature and science attainment, particuarly in biology but also more generally. You will visit children weekly and work with them on projects to monitor species or create habitats in their grounds. The ability to work with children and to handle a wide range of species is essential. You will learn social science surveying and analysis techniques as well as identification, surveying and data collection techniques suited to citizen science projects centred around children.
Models for social interaction in microbes
Microbes interact in various ways, for instance they can release antibiotics to stave off competitors, or they can release substances which help other microbes take up iron from the environment. In this way basic ecological interactions, such as competition or mutualisms can be realised in very simple organisms. This project aims to develop simple models for the interaction of microbes. Once such a model is formulated and analysed, it can then be used to study the evolution of microbes in a theoretical fashion. This project will concentrate on the production of siderophores, which allow microbes to interact through the production of a public good. This is a theoretical project that will require some experience and interest in mathematical modelling.
Models for social interaction between fungi and plants
Fungi interact with plants in various ways, for instance as pathogen, but they can also engage in a mutualistic interaction through the formation of mycorrhizas. They can release antibiotics to stave off competitors, or they can release substances which help other microbes take up iron from the environment. In this way basic ecological interactions, such as antagonisms or mutualisms can be realised. This project aims to develop simple models for the plant-fungal interaction of microbe. Once such a model is formulated and analysed, it can then be used to study the evolution of microbes in a theoretical fashion. This is a theoretical project that will require some experience and interest in mathematical modelling
Behaviourally mediated trophic cascades
Predators can affect herbivores not only directly, through predation, but also by altering their behaviour and habitat use. For instance, a common tactic for ungulates in the presence of predator risk is to increase vigilance levels while foraging, which might change their feeding behaviour and resulting browsing pressure on plants. Behaviourally mediated trophic cascades (BMTCs) occur when the fear of predation among herbivores enhances plant productivity. This dry project will summarize evidence of effects of predation risk on herbivore behaviour and habitat use as well as resulting effects on plant damage. Results of published studies on BMTCs will be combined by means of meta-analysis, which is a set of statistical methods designed to combine the results from independent studies on the same topic. Training in meta-analysis will be provided.
Buchanan A.L., Hermann S.L., Lund M., Szendrei Z. 2017. A meta-analysis of non-consumptive predator effects in arthropods: the influence of organismal and environmental characteristics. Oikos 126: 1233-1240.
Kauffman et al. 2010. Are wolves saving Yellowstone’s aspen? A landscape-level test of a behaviorally mediated trophic cascade. Ecology 91: 2742-2755.
Preisser E.L., Bolnick D.I., Bernard M.F. 2005. Scared to death? The effects of intimidation and consumption in predator-prey interactions. Ecology 86: 501-509.
Schmitz O. et al. 1997. Behaviorally mediated trophic cascades: effects of predation risk on food web interactions. Ecology 78: 1388-1399.
Effects of plant diversity on plant defences against herbivores
Diverse plant communities composed of several plant species or genotypes are known to be more resistant to herbivores as compared to species or genetic monocultures. Several mechanisms such as host plant dilution effects and physical and olfactorial masking can explain these effects. More recently evidence started to accumulate that plant defensive traits may also vary depending on whether the plant is surrounded by conspecific or heterospecific (or genetically different) neighbours. This dry project will summarize evidence of effects of plant diversity on plant anti-herbivore defences (such as chemical, physical and biotic defences) by means of meta-analysis of published studies. Meta-analysis is a set of statistical methods designed to combine the results from independent studies on the same topic; training in meta-analysis will be provided.
Kostenko O., Muder P.P.J., Courbois M., Bezemer T.M. 2017. Effects of plant diversity on the concentration of secondary plant metabolites and the density of arthropods on focal plants in the field. Journal of Ecology 105: 647-660.
Moreira X., Abdala-Roberts L., Parra-Tabla V., Mooney K. 2014. Positive effects of plant genotypic and species diversity on anti-herbivore defences in a tropical tree species. Plos One 9(8): e105438.
Next-generation pesticides: evaluating the impacts of post-neonicotinoid insecticides on bumblebee colonies
An enormous body of evidence documenting negative impacts of neonicotinoid pesticides on wild and managed bees has led to a Europe-wide ban on the use of these substances in outdoor agricultural settings. Potential replacement agrochemicals have already entered the market, and we have recently shown that Sulfoxaflor- a next-generation pesticide now registered in 81 countries, including within the EU- may have comparably negative effects on bumblebee reproductive success. There may be means to mitigate these effects, for example through exposure timings, but the extensive data required to identify these measures does not yet exist. The aim of this project is to start building this critical, and potentially high-impact, evidence base. The student will work with live bumblebee colonies in the field (our parkland campus), carrying out intensive fieldwork over the spring and early summer period, to evaluate identify high- and low-risk exposure periods and routes for bumblebee colonies. This project has the potential to provide an important and timely contribution to pollinator conservation, and students who have a strong interest in current conservation issues and fieldwork are particularly encouraged to apply.
Useful reading: Siviter H et al (2018) Sulfoxaflor exposure reduces bumblebee colony reproductive success. Nature 561:109-112
Accumulation of microplastic in the gastric mill of invasive River Thames Chinese mitten crabs
Current PhD research recently led to the publication of a paper on the high prevalence of plastic ingestion by two species of crabs, Eriocheir sinensis and Carcinus maenas in the Thames Estuary. This proposed Masters project will expand on this research and examine the gastric mill of juvenile mitten crabs migrating back upstream to complete the majority of their lifecycle in freshwater. These crabs will be collected on the Thames foreshore and then taken to the RHUL lab for microplastic examination. Polymer composition of the ingested microplastic will then be determined using the Fourier Transform Infrared Spectroscopy instrument at the Natural History Museum, London. In addition, or as the main focus for a separate project, collected Thames mitten crabs will be maintained in the RHUL aquarium. These crabs with be fed food spiked with fluorescent nylon fibres and these will be tracked and traced through the digestive tract. Furthermore, some crabs will be held until they moult with a view to clarifying if ecdysis, including replacement of the gastric mill, plays a role in removal of accumulated plastic microfibres.
McGoran, A.R., Clark, P.F., Smith, B.D & Morritt, D. (2020) High prevalence of plastic ingestion by Eriocheir sinensis and Carcinus maenas (Crustacea: Decapoda: Brachyura) in the Thames Estuary. Environmental Pollution 265: Part A, 114972. https://doi.org/10.1016/j.envpol.2020.114972
The impacts of Thames plastic pollution on native biota
Previous Masters Projects have focused on plastic pollution in the River Thames and these results have been recently published. Rowley et al., (2020) looked at the volume of microplastics (excluding fibres) in the Thames water column at Putney and Greenwich. McCoy et al., (2020) restricted her studies to the wet wipe reefs on the south back at Hammersmith and their effects on the invasive invasive Asian clam, Corbicula fluminea (Mollusca: Bivalvia). The proposed focus of this project will build on this work and will study the impacts of Thames plastic pollution on native Thames biota. This may include collecting 3 species of bivalves, gastropod snails and the crustacean, amphipod, Gammarus zaddachi. Laboratory work will comprise preparing this material for microplastic extraction and then identifying the polymer composition of these tiny fragments using the Fourier Transform Infrared Spectroscopy instrument at the Natural History Museum, London. Additional laboratory work could look at the effects of microplastics on behaviour and / or the tracking of microplastics through the digestive system to determine gut residence time in a selected model species.
McCoy, K.A., Hodgson, D.J., Clark, P.F. & Morritt, D. (2020). The effects of wet wipe pollution on the invasive Asian clam, Corbicula fluminea (Mollusca: Bivalvia) in the River Thames, London. Environmental Pollution 264: http://dx.doi.org/org/10.1016/j.envpol.2020.114577
Rowley, K., Cucknell, A-C., Smith, B.D., Clark, P.F. & Morritt, D. (2020) London’s river of plastic: high levels of microplastics in the Thames water column. Science of the Total Environment 740: http://dx.doi.org/org/10.1016/j.scitotenv.2020.140018
The shifting baseline syndrome and its impact on perceptions of environmental change
Shifting baseline syndrome describes how a lack of information about past ecological conditions can change the decisions made in conservation and environmental management. This information may be lacking as ecological information (for example from surveys) was never collected. Where this information is not available, managers may forget past ecological conditions or be too young to have experienced them, leading them to set inappropriate targets for conservation. Recent evidence however suggests that shifting baseline syndrome may have little effect on target setting by conservation managers, but could still be a big problem for public understanding of environmental change. This project will investigate the success of methods for communicating information about past environmental change. Please contact me for further information.
Useful reading: Jones et al. (2021) ‘Is there evidence of shifting baseline syndrome in environmental managers? An assessment using perceptions of bird population targets in UK nature reserves.’ Journal of Environmental Management 297: 113308.
How do we choose what to conserve? Understanding preferences for species to encourage conservation support
Why are conservation programs for fungi rare, yet conservation efforts continue for the Hainan gibbon, even though the 25 remaining individuals are unlikely to form a viable population? There are various suggestions of factors which influence people’s preferences for what to conserve, including both animal appearance and information people have about the animals, as well as individual preferences and cultural associations. This is a long-term project which aims to understand preferences for different species to promote conservation support. Current research on this topic is partnering with conservation organisations so specific questions and opportunities are always changing; please contact me for further information.
Useful reading: Curtin and Papworth (2020) ‘Colouring and size influence preferences for imaginary animals, and can predict actual donations to species-specific conservation charities’. Conservation Letters 13: e12723
Evolution of Eggshell Surface Structure and Physiology
Avian eggshells exhibit some of the most diverse and fascinating arrays of complex biological variability within the animal kingdom. The variation seen in eggshell colour and maculation (pigment spots), for example, can be found between species, within species, and even between eggs in a clutch from the same female. Eggshell maculation has fascinated scientists for decades, and many functional explanations for this maculation have been posited including crypsis, thermoregulation, microbial defence and sexual-signalling. While the variation and function of eggshell maculation has received much attention, the actual structure of the eggshell itself has received comparatively little focus. The relatively few studies that have investigated eggshell structure, particularly that of the egg surface, have found large variation in surface-structures and shell thickness. However, little is known about how these structures function, or rather, what their true function is. This project aims to characterise eggshell surface structure along the avian phylogenetic tree, and determine – through novel mechanical and structural engineering approaches – how different eggshell surface structures function. Bird eggs offer a fascinating model system, as birds breed on all seven continents on Earth; at altitudes greater than 4000 m above sea level, in temperatures ranges between -40°C and 50°C, and in environments varying from water-saturated to extremely xeric. Egg size can range from 1.4 kg to 0.4 g (for Common Ostriches Struthio camelus and Vervain Hummingbirds Mellisuga minima, respectively), while clutch size can vary from a single egg to broods of over fourteen.
Mathematical Models of Parent-of-Origin Expression
Genomic imprinting refers to the silencing of genes according to their parental origin (either paternally silenced and maternally expressed or vice versa). In this research I am interested in elaborating mathematical models that explore why would natural selection favour losing the advantages of diploidy to produce a functionally haploid locus
Mathematical Models of Gene Transmission
Meiotic drive refers to the preferential transmission of an allele (driving allele) during meiosis in diploid individuals. In this research I am interested in elaborating mathematical models that explore why is fair (Mendelian) segregation the rule and not the exception
Examining the processes that generate, maintain, and threaten biological diversity
Research in my group addresses one of the fundamental questions in evolutionary ecology: what are the ecological and evolutionary processes that generate, maintain, and constrain/threaten biological diversity? Using integrative and highly collaborative approaches, we try to answer the questions of (i) how and why organisms diversify phenotypically, (ii) what ecological and evolutionary forces shape reproductive barriers important in facilitating an initial reduction in gene flow between diverging populations, and (iii) what role human-induced environmental change has on biodiversity in general, and the stability of population differentiation among diverging populations in particular. Our main study system, currently, are livebearing fishes of the family Poeciliidae. Here, we work on invasive populations with a focus on trying to identify the mechanisms that facilitate invasion success. We also work on fish diversification along environmental gradients (including temperature, salinity, oxygen availability or resource availability gradients), and this includes work on fish from extreme environments (e.g., gradients of toxicity and pollution). There are always on-going and potential research projects available to MSc students in my lab, so for further information please contact me (email@example.com).
Gomes Silva G, E Cyubahiro, T Wronski, R Riesch, A Apio & M Plath (2020) Water pollution affects fish community structure and alters evolutionary trajectories of invasive guppies (Poecilia reticulata). Science of the Total Environment 730: 138912
Santi F, R Riesch, J Baier, M Grote, S Hornung, H Jüngling, M Plath & J Jourdan (2020) A century later: adaptive plasticity and rapid evolution contribute to geographic variation in invasive mosquitofish. Science of the Total Environment 726: 137908
Riesch R, RA Martin & RB Langerhans (2020) Multivariate character suites across multifarious environments: integrated responses of morphology and life history in Bahamas mosquitofish. Oikos 129(4): 480-492
Gao J, F Santi, L Zhou, X Wang, R Riesch & M Plath (2019) Geographical and temporal variation of multiple paternity in invasive mosquitofish (Gambusia holbrooki, Gambusia affinis). Molecular Ecology 28(24): 5315-5329
Invasion of Demon Shrimp
Demon Shrimp (Dikerogammarus haemobaphes) have established and spread across much of the UK. There is a relatively poor understanding of the impacts associated with D. haemobaphes in comparison to the closely related D. villosus, which has been extensively studied. There is some evidence to suggest that they could pose a similar threat to native organisms in freshwater systems.
There has been a recent incursion of this species into Surrey’s rivers, and there remains no effective means of controlling the spread of either Dikerogammarus species. This project would compare affected and non-affected areas, and map the spread throughout the catchment. The aim would be to model the predicted future spread as well as to assess the severity of the impact of the invader on the sampled areas.
The project, which is run in collaboration with Surrey Wildlife Trust, would comprise of both field and desk based work. River invertebrate surveys would be conducted on a selection of control and invaded sites, as well as observation of physical and chemical variables which could be indicative of impacts (e.g turbidity). Students would use currently available data on species distribution to analyse the spread of the species and model possible future dispersal using GIS. Training and assistance with both aspects would be provided.