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  • 2012-2021
  • UKRI|NERC
  • 2013
  • 2016

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  • Funder: UKRI Project Code: NE/J024481/1
    Funder Contribution: 372,389 GBP

    We will examine the genetic basis of sex ratio behaviour in the parasitoid wasp Nasonia vitripennis. Female N. vitripennis facultatively change their offspring sex ratios in line with Hamilton's theory of Local Mate Competition (LMC). LMC arises from competition between related males (e.g. brothers) for mates, and can occur when mating occurs in localised groups, for instance amongst groups of kin. When LMC is intense (e.g. if all males are brothers), the optimal sex ratio is a female-biased one. This bias reduces competition amongst sons and increases the number of mates for those sons. As LMC declines, so does the predicted sex ratio bias. The degree of LMC depends on how many females lay eggs on a patch of hosts (and how many eggs they lay). Over the last decade, we have explored the cues female Nasonia use when allocating sex under LMC. With a robust theoretical framework, we now have a remarkably good understanding of facultative sex allocation under LMC at the phenotypic level in Nasonia. However, our understanding of the genetics of sex ratio is more rudimentary, especially in terms of the mechanism of sex allocation. Thus far, we have some picture of the quantitative genetics of sex ratio in Nasonia (estimates of heritability, input of new mutations, and the identification of four Quantitative Trait Loci, or QTL). We have also begun to explore what genes are expressed during oviposition. In this proposal, we will build on this work to explore the genetic basis of sex ratio variation and control in Nasonia, using three complementary approaches. First, we will first follow-up our recent QTL study using a Restriction Site Associated DNA sequencing ("RAD-seq") approach and a repeat of the cross between High and Low sex ratio lines drawn from the same natural population. RAD-seq can generate thousands of markers across a genome enabling finer-scale QTL mapping projects. We will also use the data we generate to test for clutch size variation QTL, testing for loci pleiotropically influencing both sex ratio and clutch size. Second, we will follow-up our recent gene expression work to explore changes in gene expression associated with exposure to different LMC environments and different combinations of LMC cues. Back in 2004, Shuker & West experimentally showed that female Nasonia vitripennis responded differentially to "host" versus "social" LMC cues. We will follow a similar protocol, assaying the transcriptomes of the focal females using RNA-seq on the Illumina platform. Our aim is to see whether we can link patterns of gene expression to subtle environmental differences which we know have a big effect on the sex ratio phenotype. Third, we will test whether or not epigenetic modifications of DNA (specifically DNA methylation) are associated with the regulation of sex ratio behaviour. The extent to which epigenetic control of gene expression influences behaviour is currently the focus of much interest, both in humans and other vertebrates, but also increasingly in insects. First, we will look for patterns of differential methylation associated with either mating (as females switch from mate-searching to host-searching) and/or interactions with LMC cues whilst ovipositing. Second, we will disrupt DNA methylation and look for changes in sex allocation. If DNA methylation helps regulate gene networks associated with sex ratio behaviour, then we will see patterns of differential methylation across the treatments in the first experiment and changes in sex allocation across the treatments in the second. Taken together, these approaches will address both the genetic architecture of sex ratio variation and also the genes and gene pathways associated with sex allocation, and whether or not the regulation of those pathways involves DNA methylation. They will provide complementary sets of candidate genes, enabling the functional genomic/molecular evolution studies required to fully realise the genotype-phenotype link.

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  • Funder: UKRI Project Code: NE/J01219X/1
    Funder Contribution: 278,765 GBP

    All living organisms that make up life on Earth are made from a profusion of elements in the periodic table, including trace metals. However, in addition to oxygen (O) and hydrogen (H), the constituents of water, the three most important are Carbon (C), Nitrogen (N) and Phosphorus (P). These have become known as the Macro-Nutrients. These macronutrients are in constant circulation between living organisms (microbes, plants, animals, us) and the environment (atmosphere, land, rivers, oceans). Until human intervention (circa post industrial revolution and even more so since WWII) these 'cycles' were largely in balance: plants took up CO2 and produced O2 and, in order to do so, took up limited amounts of N and P from the environment (soils, rivers) and, on death, this "sequestered" C,N,P was returned back to the Earth. The problem is that human or anthropogenic activity has put these key macro-nutrient cycles out of balance. For example, vast quantities of once fossilised carbon, taken out of the atmosphere before the age of the dinosaurs, are being burnt in our power stations and this has increased atmospheric CO2 by about 30 % in recent times. More alarmingly, perhaps, is that man's industrial efforts have more than doubled the amount of N available to fertilize plants, and vast amounts of P are also released through fertilizer applications and via sewage. As the population continues to grow, and the developing world catches up, and most likely overtakes, the western world, these imbalances in the macro-nutrient cycles are set to be exacerbated. Indeed, such is the impact of man's activity on Earth that some are calling this the 'Anthropocene': Geology's new age. The environmental and social problems associated with these imbalances are diverse and complex; most people would be familiar with the ideas behind global warming and CO2 but fewer may appreciate the links to methane and nitrous oxide or the potential health impacts of excess nitrate in our drinking water. These imbalances are not being ignored and indeed a great deal of science, policy and management has been expended to mitigate the impacts of these imbalances. However, despite our progress in the science underpinning this understanding over the last 30-40 years or so, too much of this science has been focused on the individual macro-nutrients e.g. N, and in isolated parts of the landscape e.g. rivers. To compound this even further, such knowledge and understanding has often been garnered using disparate, or sometimes even antiquated, techniques. Anthropogenic activity has spread this macro-nutrient pollution all over the landscape. Some of it is taken up by life, some is stored, but a good deal of it works its way through the landscape towards our already threatened seas. We need to understand what happens to the macronutrients as they move, or flux, through different parts of the landscape and such understanding can only come about by a truly integrated science programme which examines the fate of the macronutrients simultaneously in different parts of the landscape. Here we will for the first time make parallel measurements, using truly state-of-the-art technologies, of the cycling and flux of all three macronutrients on the land and in the rivers that that land drains and, most importantly, the movement of water that transports the macro-nutrients from the land to the rivers e.g. the hydrology. Moreover, we will compare these parallel measurements across land to river in different types of landscapes: clay, sandstone and chalk, subjected to different agricultural usage in order to understand how the cycling on the land is connected, via the movement of water, to that in the rivers.

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  • Funder: UKRI Project Code: NE/J023833/1
    Funder Contribution: 503,777 GBP

    Over 100 million people drink groundwaters containing naturally occurring arsenic (As) higher than the WHO guide value (10 ppb). In Bangladesh alone, 20% of all deaths in impacted areas are attributable to such exposure (ARGOS, 2010) - this corresponds to about 30,000 premature deaths every year. Studies provide evidence for both in-aquifer and near-surface sediment As sources. ISLAM (2004) demonstrated that As release occurs from within the aquifer sediments & highlighted the importance of organic matter (OM) in this process. BENNER (2008) & POLIZZOTTO (2008) have suggested, instead, that As release mostly occur in near-surface sediments BEFORE entering the aquifer. Determining the relative importance and controls of As release from the near surface sediments (typically 5 m - 15 m depth) from that which occurs within the aquifer, as well as assessing the various controls on As once in solution, are critical if we are to develop the required process oriented understanding of As mobility in drinking water supplies. Identifying study areas that reveal these processes is hard. For example, massive groundwater abstraction in the densely populated areas of West Bengal and Bangladesh has resulted in a complex subsurface hydrological environment which makes tracking As release mechanisms almost impossible. However, the absence of such extensive abstraction in As-rich aquifers of Cambodia means that this subsurface hydrological environment remains largely unaltered. Recent work by project partners (Stanford) means that a representative high As area has been identified and the hydrogeology established - but not on a scale or with the geochemical techniques required to establish a full understanding. We will drill 77 new and relatively inexpensive boreholes at the Cambodian site after using geophysics (supplied by our BGS partner) to determine the best locations. These new wells will allow us to collect samples across established As hotspots at a scale over which the As release process must be operating. Three well nests will sample an oxbow lake overlying an As contaminated aquifer, a sand 'window' through the overlying clay sediments and a control through the clay sediment overlying the As contaminated main aquifer. Two further well sequences will allow sampling of the main aquifer along its flow path. A 5-20m tube-well separation represents ~5-250 years of aquifer chemical evolution. Our Cambodian partners at RUPP & RDI will give local logistic support. We have been working closely our NERC Radiocarbon Lab partner. We show within our proposal that 14-C dating of organic matter in sediments and of dissolved inorganic and organic carbon in groundwaters provides a profound technique for identifying organic matter sources, central to resolving As release mechanisms. Similarly, pilot work withour NERC stable isotope facility partner has shown the utility of applying delta-18O and delta-D data to quantify surface water input into the main aquifer. Both of these approaches, combined with Manchester anion, cation and inorganic assay of sediments as well as tritium and 4-He techniques to date any young water input or ancient fluid contribution, will provide a fully comprehensive geochemical approach. With the high spatial resolution of sampling we expect this approach to make a major contribution in: i) quantifying the flux of As on a spatial scale alongside secular changes in As hazard from these two potential As sources; ii) identifying the dominant source of OM responsible for driving As release from these locations; and iii) identifying the controlling processes and mechanisms responsible for As release in these profiles. Together this understanding will enable the development of a quantitative model with predictive capacity that will inform governmental agencies responsible for drinking water and irrigation supplies to assess how continuation of, or changing, water use practice will impact future water supply As risks.

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  • Funder: UKRI Project Code: NE/K001701/1
    Funder Contribution: 718,461 GBP

    The large continental land masses are surrounded by extensive shallow (ca 100m depth) seas known as the 'shelf seas'. These act as the boundary between the massively perturbed terrestrial environment and the vast open ocean marine system, and have huge socio-economic importance. They are the primary regions of human marine resource exploitation, including both renewable and fossil fuel energy sources, recreation, trade and food production. Although comprising only about 5% of the global ocean surface area, the shelf seas provide 90% of the global fish catches which form an important source of food to much of the global population. They also play an important role in the ecosystem services provided by the oceans as a whole, in particular in storing carbon away from the atmosphere. Physical and biochemical processes in shelf seas influence the removal of CO2 from the atmosphere and the subsequent storage of carbon in the deep ocean. Biological growth draws carbon out of the water, which is then replaced by carbon in CO2 from the atmosphere. In the shelf seas this growth is supported by terrestrial and open ocean sources of nutrients, implying intimate roles for both the terrestrial biosphere and the open ocean environment in regulating shelf sea climate services. The oceans can also be a major source or sink for other greenhouse gases, including nitrous oxide (N2O), with the shallow shelf seas thought to play a key role. The spatial extent of the submerged continental shelves varies greatly. The NW European shelf sea is one of the largest and hence is likely to play a significant role in marine biogeochemical cycling, alongside providing a useful model for other systems However, even in this relatively well studied region, we lack a good understanding of the principal controls on the cycling of carbon and the major nutrient elements, nitrogen, phosphorous and silicon. Consequently it is also difficult to predict how the cycling of these elements and hence the carbon removal they support may be altered by ongoing and potential future global change. Our proposal aims to address these uncertainties through a comprehensive study of the cycling of the major nutrients and carbon throughout the water column over the NW European shelf sea system. Through close collaboration with a range of partners, we will undertake a year-long observation programme of the whole NW European continental shelf. We will measure the seawater concentrations of the major forms of carbon and nutrients. Combining these with physical water transports and measured transfer of gases (specifically CO2 and N2O) between the air and sea surface, we will quantify the major fluxes of nutrients and carbon between the shelf sea and both the adjacent deep ocean and atmosphere. This will definitively establish the role of this shelf system in the global carbon and nutrient cycles. We will also undertake 4 dedicated research cruises focused on understanding the seasonal cycle of biological and chemical processing of the different forms of the nutrients and carbon. We will measure the rates at which both the photosynthetic and consumer plankton incorporate nutrients and carbon into their cellular material, and subsequently how the combined activity of this biological/chemical system influences the cycling of the major elements. This will allow us to understand the ways in which the role of the shelf system in global cycles is maintained. The combined work delivered by both this proposal and the other programme workpackages will allow us to identify aspects of the NW European shelf system which may be susceptible to ongoing or future environmental changes. Such knowledge will provide both enhanced scientific understanding and improved predictive tools for policy makers and other stakeholders.

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  • Funder: UKRI Project Code: NE/K011057/1
    Funder Contribution: 25,455 GBP

    Generation of ocean lithosphere by seafloor spreading at mid-ocean ridges is one of the fundamental geological processes operating on Earth. One of the most important yet most intractable problems is to understand how the magma reservoir beneath ridges generates the lower crust, especially at fast spreading rates. Gabbroic rocks from the lower crust are normally inaccessible, but are exposed tectonically on the flanks of the Hess Deep rift in the Pacific Ocean. IODP Expedition 345 aims to provide a unique suite of lower oceanic crustal samples from this locality that will yield insights into magmatic and tectonic processes involved in seafloor spreading. As part of this endeavour, palaeomagnetic data will be collected from recovered core pieces and will be critical to understanding the evolution of the lower crust at this site. These data will provide valuable information on the direction and strength of magnetization locked into the gabbroic rocks we expect to encounter, providing a marker that can be used to infer the amount of tectonic rotation that has affected the site and insights into the contribution that lower crustal rocks make to marine magnetic anomalies. In addition, we intend to use a combination of palaeomagnetic data and geophysical images of the inside of borehole walls to reorient some of the core pieces recovered by drilling, thereby allowing other directional properties (e.g. structural data) to be restored to the correct geographical reference frame.

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  • Funder: UKRI Project Code: NE/K002430/1
    Funder Contribution: 68,520 GBP

    The proposal aims to advance our understanding and predictions of interactions between hydrology and nutrient transfers in headwater catchments in the UK, under climate and land use change scenarios to 2050, using the very latest data and modeling approaches available for the UK. The study catchments will be the UK Demonstration Test Catchments (DTCs) and the aims will be achieved through: (1) using existing climate model scenarios to set baseline outcomes for change; (2) localized DTC-focused stakeholder elicitation workshops to develop scenarios for land use changes in response to the climate scenarios; (3) simulating current hydrological events and future changes in catchment hydrology in response to changing climate/land use; (4) new understanding of phosphorus (P) behaviour in extreme hydrological conditions, using experiments and newly available high resolution observations from the DTCs to inform model development; (5) improved prediction (with uncertainty) of future P behaviour scenarios arising from the new understanding of hydrology-P interactions; (6) attempting to scale up the information from headwater-catchment to full basin scale, and; (7) compare model performance with existing P models and assess uncertainties involved in this process, with further iterations of stakeholder consultation. We shall focus on the 10 km2 scale because this matches the size of the nine study catchments of the Defra DTCs (from the Eden, Wensum and Avon DTCs), which are our chosen study areas; this scale also represents the ideal size for studying processes along the mobilisation-delivery-in-stream impact 'transfer continuum'. These integrated studies will produce a prototype quantitative assessment and prediction of nutrient fluxes. Our hypothesis is that increased seasonal variability in storm patterns (more extreme events, long drought periods), combined with interactions with land use change, will greatly alter future dissolved and particulate P fluxes across the land-water continuum and subsequent retention in-stream and downstream eutrophication risk. We shall extend our initial 'Systems Evidence Based Assessment Methodology (SEBAM)' study that focused on mobilization of P at the farm scale (recently published by the team), into a prototype modeling framework that includes source, mobilization, delivery and in-stream processing functions for predicting P fluxes from UK headwater catchments, and considers land use change, and use this framework (combined with knowledge from other projects involving the team) to scale up our information to define the potential for predicting other nutrient behaviours at the full basin scale. We will capitalize on the new and unique high quality, high temporal resolution P monitoring data that is starting to emerge from the nine Defra DTC sub-catchments. A unique and exciting aspect of the work will be the use of expert elicitation procedures that incorporate fuzzy uncertainty-based analyses to develop tailored land use scenarios (building on the UK Land Use Foresight Initiative) for each of the unique landscape typologies for the 9 DTC focus catchments. Combining this information with the latest climate scenarios for the UK, we will include new developments in high-resolution numerical weather prediction. We shall then use these scenarios to study the impacts of climate and land use change to 2050 on hydrology, P mobilization, delivery and in-stream processing, informed from new empirical learning and experimentation. Model outputs will then be validated for other catchments in the wider UK (Conwy, Ribble, Tarland) using data from linked projects and our partners. Throughout the project, the outcomes will be tested with stakeholders. This will deliver a locally owned knowledge-based framework for understanding and managing future nutrient transfers from rural catchment systems, and some exciting new science on P transfers.

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  • Funder: UKRI Project Code: NE/L000253/1
    Funder Contribution: 406,064 GBP

    The impact of radioactivity on humans and the wider environment is controlled by the behaviour of the radionuclides in groundwaters, soils and sediments, and this behaviour is dictated by the quantities of radionuclides, and their chemical forms. We will study some of the radionuclides which are particularly important because they are potentially present in relatively large quantities, are environmentally mobile, and are readily taken up by living organisms. The main radionuclides we are going to study are: Carbon-14, which occurs in nature, but was produced back in the 1950s and 60s through nuclear weapons testing, and is also present in nuclear wastes; and Uranium (together with its decay product radium) which is present in nature, and also in some nuclear wastes. We will use four areas of the UK which contain elevated levels of these radionuclides as our study sites. These are South Terras (an old uranium mine in Cornwall), the Needle's Eye (a uranium mineral vein in SW Scotland), the Esk Estuary in NW England, and offshore sediments in the NE Irish Sea. At these last two sites, the sediments contain elevated levels of radioactivity from authorised Sellafield discharges, mainly in the 1970s. As well as studying how radioactivity occurs in, and moves through, the soils, waters, plants and (in the offshore sediments) animals, we want to understand the environmental and biological processes which control this movement. To do this, we will do a series of laboratory experiments, looking at the way soil/sediment conditions influence the radionuclide concentrations in solution, the form of the radionuclides in the solution, the way radionuclides are taken up into plants and animals, and the way they are distributed in plant tissues. We will use the results from our field and laboratory studies to develop and test mathematical models of radionuclide transport and transfer processes. These are important because they allow us to predict behaviour, rather than having to make measurements. These predictive models can be used in assessing environmental impacts, cleaning up contaminated land and predicting the long term impact of radioactive waste disposals.

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  • Funder: UKRI Project Code: NE/K00459X/1
    Funder Contribution: 49,606 GBP

    Many conservation organisations have initiatives for protecting plants and animals which operate at the landscape scale. For example there are currently 110 Living Landscape Initiatives (Wildlife Trusts), 40 Futurescapes (RSPB), and 8 Integrated Biodiversity Delivery Areas (Natural England), plus the Nature Improvement Areas (Defra). Food webs are very useful tool for studying communities of plants and animals and over a decade they have developed from simple descriptions of communities, to tools that can predict the results of environmental changes, such as global warming or species loss. Despite the strong move to landscape-level conservation though, food web studies are almost invariably conducted in small plots (e.g. 100 m2) in single habitats, to investigate, for example, pests and their natural enemies in a crop field, or pollinators and their nectar plants in a meadow. Our aim here is to initiate a major change in the way we study food webs by working at the scale of the landscape (defined as a mosaic of different habitats). This proposal will allow us for the first time to understand how food webs interact in real world landscapes and how the various habitats (e.g. woodlands vs heathland vs salt marsh) affect the structure of landscape food webs, and delivery of ecosystem services such as pest control and pollination. Our pilot data suggest that a mosaic of habitats is likely to be more resilient in to environmental damage than individual habitats. Similarly we predict better delivery of ecosystem services if a mixture of habitats are conserved. There is considerable opportunity for win : win scenarios here - better conservation of wildlife and better provision of pollination and pest control, the latter being critical for food security. There are five objectives in our proposal: Objective 1: Time is money in practical conservation biology, and networks which are more efficient to construct (i.e. cheaper!) are more likely to be used by conservation biologists. We will test whether food webs based on reduced sampling can still be used to identify the functionally most important species (i.e. those that support the most other species). Objective 2: We will test whether landscapes composed of multiple habitats are more resilient to species loss than landscapes composed of fewer habitats. Objective 3: Species that move between habitats are rarely considered in practical conservation, but could be critical for ecosystem resilience as they effectively "glue" the various habitats together. We will develop new mathematical tools to calculate how separate the various habitats are in a landscape, and conversely, how well they are glued together. Objective 4: If nature reserves are adjacent to farmland, there is potential for the former to provide ecosystem services to the latter via mobile pollinators and parasitoids. We will test whether pollination and pest control improve in patches of strawberry plants as the number of adjacent natural habitats increases. Objective 5: We will publish our findings in scientific journals and convey them to a wider audience, by: a) running three workshops for 90 nature reserve managers; b) working with the Bee Guardian Foundation to turn five towns in England into Bee Guardians; c) commissioning final year students to write reports for practitioners; d) running a blog; e) communicating findings to influential policy-makers. The research team has the skills and experience to conduct research which will improve landscape conservation projects significantly. Led by Memmott, the team consists of ecologists and computer scientists, museum taxonomists and conservation ecologists. The latter all have long-term interests and influence in multiple landscape conservation projects and as can be seen from the letters of support, our project will provide the information that practitioners need for evidence-based landscape conservation.

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  • Funder: UKRI Project Code: NE/K004697/1
    Funder Contribution: 435,600 GBP

    In 1992 John Gray wrote a now famous book 'Men are from Mars, Women are from Venus' (Harper Collins). In this he illustrated the many differences between males and females using the book title as the central metaphor. He imagined that the sexes are so different that one might as well consider them as originating from different planets. One of the main ideas in the book is that men and women assess or 'score' the currency of their relationship - but that they score according to different scales! This is evident, Gray suggests, when the amount of give and take within a relationship is not assessed or scored equitably. This can lead to a perceived or actual imbalance in the relationship, leading to resentment and so on. Overall, the ideas in this book proved to be a popular way of thinking about how relationships work - or not - in terms of sex differences. Whatever one thinks about the book and its legacy, the central ideas described above accord surprisingly well with evidence drawn from plants and animals. It was realised in the 1970s, for example, that rather than being co-operative ventures, the interactions between the sexes over reproduction are often characterized by conflict rather than co-operation. Hence the sexes often 'disagree' about how much energy and resources to invest in reproduction and how often to make that investment. A good example is evolutionary disagreements over how often to mate. Males often gain from mating frequently and females often do not. Furthermore, females often suffer significantly reduced lifespan from mating too frequently (an effect that we now know is also true in humans). Such lifespan reduction arising from mating frequently is not incurred to anything like the same degree in males. It has recently been realised that these sexual interactions, i.e. the effect of males on female lifespan and vice versa, could actually underlie an important and long-standing puzzle: why it is that males and females often have very different longevity. For example, human females generally live at least 4 years longer than men. Such sex differences are also extremely common in the animal world, and can occur in either direction. In experimental settings the way that lifespan is measured, and longevity 'genes' identified, is often to use non-reproductive individuals, or those that are mated early in life and then kept away from the other sex. Such tests are therefore missing something important - the effects of regular exposure to the other sex. It is now believed that the 'sexual conflicts' of the sort described by Gray and earlier considered by evolutionary biologists such as Geoff Parker, Richard Dawkins and Bill Rice can go a long way to explaining sex differences in lifespan and ageing by considering the effects of one sex upon the other. The central aim of the research proposed here is to evaluate this idea and to examine the underlying genetic basis of the differences in these necessary, but sometimes dangerous, liaisons between the sexes. The work is important because it will be the first full test of these ideas and the first to probe the genomic basis of sex differences caused by sexual conflict. Our proof of principle data gathered for this proposal show that the methods proposed can identify novel ageing genes. The work is also useful because these ideas can also be fed directly into husbandry practices for pest control in the applied sector. Overall this is an exciting and novel project that will test whether sexual conflict can lead to increased ageing and will identify the underlying genes that are responsible.

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  • Funder: UKRI Project Code: NE/K006185/1
    Funder Contribution: 60,924 GBP

    Methane is the second most important greenhouse gas and contributes to the atmospheric chemistry affecting ozone. Southern tropical methane sources and sinks constitute a significant component of the global methane budget. The current major anomaly in southern methane growth rate is among the largest on record. Yet despite its importance, tropical methane variability has received relatively little study. This proposal is to investigate the southern tropical methane budget. The work will improve quantification of southern tropical sources and the understanding of the mechanisms of sudden growth events. Southern tropical methane sources are varied, each having their own isotopic signature in the methane they produce. Wetlands are very extensive in southern tropical S. America and in western parts of southern sub-equatorial Africa, but data on methane emissions from these wetlands are very sparse. Fires in savanna grasslands in Africa and S. America are also significant sources, as are the large ruminant animal populations. Anthropogenic sources are also increasing, with major recent hydrocarbon discoveries. Tropical OH is the major global methane sink. Ascension Is. is a uniquely located, UK-administered, experimental site for studying the methane budget. At surface the air is almost always SE Trade wind, which arrives from the South Atlantic middle latitudes, and, after Ascension, becomes the background air for Amazonia. Above the trade wind inversion, the air over Ascension is tropical, its origin switching regularly between Africa and S. America. Currently Royal Holloway sustains continuous high-precision CH4 and CO2 measurement (CRDS instrument) and also flask measurement of d13C in CH4 on Ascension, as well as on E. Falkland Is. and on RRS JC Ross. Methodologically, the project will focus on the measurement of methane in the southern tropics, carrying out campaign studies, especially on Ascension, and modelling the results. Measurement will include continuous measurement by CRDS in Ascension, E. Falklands, bi-annual Atlantic transects by RRS JC Ross, and Tedlar bag sample collection for CH4 and d13C of CH4 in Uganda, Peru and Bolivia. Campaign studies will include installation of a CRDS instrument in Peru and use of an unmanned aerial system (UAV) to sample above the Trade Wind Inversion on Ascension, as well as source campaigns to characterise d13C signatures of CH4 emissions in Africa and S. America. The proposed helicopter UAV deployment exploits new expertise and would represent an important UK deployment of a substantial UAV for atmospheric sampling. This deployment therefore addresses one of the key science challenges set out in the NERC scoping study for next-generation platforms for Earth & Environmental Science. Modelling studies are also state-of-the-art, and will include regional trajectory analysis to assess source inputs across Africa and S. America, and global modelling of d13C of CH4, tested against the measurements made in the project. The results will be used to assess the importance of southern tropical methane in the global budget, the causes of rapid past changes, and the possibility of future rapid growth in emissions.

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  • Funder: UKRI Project Code: NE/J024481/1
    Funder Contribution: 372,389 GBP

    We will examine the genetic basis of sex ratio behaviour in the parasitoid wasp Nasonia vitripennis. Female N. vitripennis facultatively change their offspring sex ratios in line with Hamilton's theory of Local Mate Competition (LMC). LMC arises from competition between related males (e.g. brothers) for mates, and can occur when mating occurs in localised groups, for instance amongst groups of kin. When LMC is intense (e.g. if all males are brothers), the optimal sex ratio is a female-biased one. This bias reduces competition amongst sons and increases the number of mates for those sons. As LMC declines, so does the predicted sex ratio bias. The degree of LMC depends on how many females lay eggs on a patch of hosts (and how many eggs they lay). Over the last decade, we have explored the cues female Nasonia use when allocating sex under LMC. With a robust theoretical framework, we now have a remarkably good understanding of facultative sex allocation under LMC at the phenotypic level in Nasonia. However, our understanding of the genetics of sex ratio is more rudimentary, especially in terms of the mechanism of sex allocation. Thus far, we have some picture of the quantitative genetics of sex ratio in Nasonia (estimates of heritability, input of new mutations, and the identification of four Quantitative Trait Loci, or QTL). We have also begun to explore what genes are expressed during oviposition. In this proposal, we will build on this work to explore the genetic basis of sex ratio variation and control in Nasonia, using three complementary approaches. First, we will first follow-up our recent QTL study using a Restriction Site Associated DNA sequencing ("RAD-seq") approach and a repeat of the cross between High and Low sex ratio lines drawn from the same natural population. RAD-seq can generate thousands of markers across a genome enabling finer-scale QTL mapping projects. We will also use the data we generate to test for clutch size variation QTL, testing for loci pleiotropically influencing both sex ratio and clutch size. Second, we will follow-up our recent gene expression work to explore changes in gene expression associated with exposure to different LMC environments and different combinations of LMC cues. Back in 2004, Shuker & West experimentally showed that female Nasonia vitripennis responded differentially to "host" versus "social" LMC cues. We will follow a similar protocol, assaying the transcriptomes of the focal females using RNA-seq on the Illumina platform. Our aim is to see whether we can link patterns of gene expression to subtle environmental differences which we know have a big effect on the sex ratio phenotype. Third, we will test whether or not epigenetic modifications of DNA (specifically DNA methylation) are associated with the regulation of sex ratio behaviour. The extent to which epigenetic control of gene expression influences behaviour is currently the focus of much interest, both in humans and other vertebrates, but also increasingly in insects. First, we will look for patterns of differential methylation associated with either mating (as females switch from mate-searching to host-searching) and/or interactions with LMC cues whilst ovipositing. Second, we will disrupt DNA methylation and look for changes in sex allocation. If DNA methylation helps regulate gene networks associated with sex ratio behaviour, then we will see patterns of differential methylation across the treatments in the first experiment and changes in sex allocation across the treatments in the second. Taken together, these approaches will address both the genetic architecture of sex ratio variation and also the genes and gene pathways associated with sex allocation, and whether or not the regulation of those pathways involves DNA methylation. They will provide complementary sets of candidate genes, enabling the functional genomic/molecular evolution studies required to fully realise the genotype-phenotype link.

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  • Funder: UKRI Project Code: NE/J01219X/1
    Funder Contribution: 278,765 GBP

    All living organisms that make up life on Earth are made from a profusion of elements in the periodic table, including trace metals. However, in addition to oxygen (O) and hydrogen (H), the constituents of water, the three most important are Carbon (C), Nitrogen (N) and Phosphorus (P). These have become known as the Macro-Nutrients. These macronutrients are in constant circulation between living organisms (microbes, plants, animals, us) and the environment (atmosphere, land, rivers, oceans). Until human intervention (circa post industrial revolution and even more so since WWII) these 'cycles' were largely in balance: plants took up CO2 and produced O2 and, in order to do so, took up limited amounts of N and P from the environment (soils, rivers) and, on death, this "sequestered" C,N,P was returned back to the Earth. The problem is that human or anthropogenic activity has put these key macro-nutrient cycles out of balance. For example, vast quantities of once fossilised carbon, taken out of the atmosphere before the age of the dinosaurs, are being burnt in our power stations and this has increased atmospheric CO2 by about 30 % in recent times. More alarmingly, perhaps, is that man's industrial efforts have more than doubled the amount of N available to fertilize plants, and vast amounts of P are also released through fertilizer applications and via sewage. As the population continues to grow, and the developing world catches up, and most likely overtakes, the western world, these imbalances in the macro-nutrient cycles are set to be exacerbated. Indeed, such is the impact of man's activity on Earth that some are calling this the 'Anthropocene': Geology's new age. The environmental and social problems associated with these imbalances are diverse and complex; most people would be familiar with the ideas behind global warming and CO2 but fewer may appreciate the links to methane and nitrous oxide or the potential health impacts of excess nitrate in our drinking water. These imbalances are not being ignored and indeed a great deal of science, policy and management has been expended to mitigate the impacts of these imbalances. However, despite our progress in the science underpinning this understanding over the last 30-40 years or so, too much of this science has been focused on the individual macro-nutrients e.g. N, and in isolated parts of the landscape e.g. rivers. To compound this even further, such knowledge and understanding has often been garnered using disparate, or sometimes even antiquated, techniques. Anthropogenic activity has spread this macro-nutrient pollution all over the landscape. Some of it is taken up by life, some is stored, but a good deal of it works its way through the landscape towards our already threatened seas. We need to understand what happens to the macronutrients as they move, or flux, through different parts of the landscape and such understanding can only come about by a truly integrated science programme which examines the fate of the macronutrients simultaneously in different parts of the landscape. Here we will for the first time make parallel measurements, using truly state-of-the-art technologies, of the cycling and flux of all three macronutrients on the land and in the rivers that that land drains and, most importantly, the movement of water that transports the macro-nutrients from the land to the rivers e.g. the hydrology. Moreover, we will compare these parallel measurements across land to river in different types of landscapes: clay, sandstone and chalk, subjected to different agricultural usage in order to understand how the cycling on the land is connected, via the movement of water, to that in the rivers.

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  • Funder: UKRI Project Code: NE/J023833/1
    Funder Contribution: 503,777 GBP

    Over 100 million people drink groundwaters containing naturally occurring arsenic (As) higher than the WHO guide value (10 ppb). In Bangladesh alone, 20% of all deaths in impacted areas are attributable to such exposure (ARGOS, 2010) - this corresponds to about 30,000 premature deaths every year. Studies provide evidence for both in-aquifer and near-surface sediment As sources. ISLAM (2004) demonstrated that As release occurs from within the aquifer sediments & highlighted the importance of organic matter (OM) in this process. BENNER (2008) & POLIZZOTTO (2008) have suggested, instead, that As release mostly occur in near-surface sediments BEFORE entering the aquifer. Determining the relative importance and controls of As release from the near surface sediments (typically 5 m - 15 m depth) from that which occurs within the aquifer, as well as assessing the various controls on As once in solution, are critical if we are to develop the required process oriented understanding of As mobility in drinking water supplies. Identifying study areas that reveal these processes is hard. For example, massive groundwater abstraction in the densely populated areas of West Bengal and Bangladesh has resulted in a complex subsurface hydrological environment which makes tracking As release mechanisms almost impossible. However, the absence of such extensive abstraction in As-rich aquifers of Cambodia means that this subsurface hydrological environment remains largely unaltered. Recent work by project partners (Stanford) means that a representative high As area has been identified and the hydrogeology established - but not on a scale or with the geochemical techniques required to establish a full understanding. We will drill 77 new and relatively inexpensive boreholes at the Cambodian site after using geophysics (supplied by our BGS partner) to determine the best locations. These new wells will allow us to collect samples across established As hotspots at a scale over which the As release process must be operating. Three well nests will sample an oxbow lake overlying an As contaminated aquifer, a sand 'window' through the overlying clay sediments and a control through the clay sediment overlying the As contaminated main aquifer. Two further well sequences will allow sampling of the main aquifer along its flow path. A 5-20m tube-well separation represents ~5-250 years of aquifer chemical evolution. Our Cambodian partners at RUPP & RDI will give local logistic support. We have been working closely our NERC Radiocarbon Lab partner. We show within our proposal that 14-C dating of organic matter in sediments and of dissolved inorganic and organic carbon in groundwaters provides a profound technique for identifying organic matter sources, central to resolving As release mechanisms. Similarly, pilot work withour NERC stable isotope facility partner has shown the utility of applying delta-18O and delta-D data to quantify surface water input into the main aquifer. Both of these approaches, combined with Manchester anion, cation and inorganic assay of sediments as well as tritium and 4-He techniques to date any young water input or ancient fluid contribution, will provide a fully comprehensive geochemical approach. With the high spatial resolution of sampling we expect this approach to make a major contribution in: i) quantifying the flux of As on a spatial scale alongside secular changes in As hazard from these two potential As sources; ii) identifying the dominant source of OM responsible for driving As release from these locations; and iii) identifying the controlling processes and mechanisms responsible for As release in these profiles. Together this understanding will enable the development of a quantitative model with predictive capacity that will inform governmental agencies responsible for drinking water and irrigation supplies to assess how continuation of, or changing, water use practice will impact future water supply As risks.

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  • Funder: UKRI Project Code: NE/K001701/1
    Funder Contribution: 718,461 GBP

    The large continental land masses are surrounded by extensive shallow (ca 100m depth) seas known as the 'shelf seas'. These act as the boundary between the massively perturbed terrestrial environment and the vast open ocean marine system, and have huge socio-economic importance. They are the primary regions of human marine resource exploitation, including both renewable and fossil fuel energy sources, recreation, trade and food production. Although comprising only about 5% of the global ocean surface area, the shelf seas provide 90% of the global fish catches which form an important source of food to much of the global population. They also play an important role in the ecosystem services provided by the oceans as a whole, in particular in storing carbon away from the atmosphere. Physical and biochemical processes in shelf seas influence the removal of CO2 from the atmosphere and the subsequent storage of carbon in the deep ocean. Biological growth draws carbon out of the water, which is then replaced by carbon in CO2 from the atmosphere. In the shelf seas this growth is supported by terrestrial and open ocean sources of nutrients, implying intimate roles for both the terrestrial biosphere and the open ocean environment in regulating shelf sea climate services. The oceans can also be a major source or sink for other greenhouse gases, including nitrous oxide (N2O), with the shallow shelf seas thought to play a key role. The spatial extent of the submerged continental shelves varies greatly. The NW European shelf sea is one of the largest and hence is likely to play a significant role in marine biogeochemical cycling, alongside providing a useful model for other systems However, even in this relatively well studied region, we lack a good understanding of the principal controls on the cycling of carbon and the major nutrient elements, nitrogen, phosphorous and silicon. Consequently it is also difficult to predict how the cycling of these elements and hence the carbon removal they support may be altered by ongoing and potential future global change. Our proposal aims to address these uncertainties through a comprehensive study of the cycling of the major nutrients and carbon throughout the water column over the NW European shelf sea system. Through close collaboration with a range of partners, we will undertake a year-long observation programme of the whole NW European continental shelf. We will measure the seawater concentrations of the major forms of carbon and nutrients. Combining these with physical water transports and measured transfer of gases (specifically CO2 and N2O) between the air and sea surface, we will quantify the major fluxes of nutrients and carbon between the shelf sea and both the adjacent deep ocean and atmosphere. This will definitively establish the role of this shelf system in the global carbon and nutrient cycles. We will also undertake 4 dedicated research cruises focused on understanding the seasonal cycle of biological and chemical processing of the different forms of the nutrients and carbon. We will measure the rates at which both the photosynthetic and consumer plankton incorporate nutrients and carbon into their cellular material, and subsequently how the combined activity of this biological/chemical system influences the cycling of the major elements. This will allow us to understand the ways in which the role of the shelf system in global cycles is maintained. The combined work delivered by both this proposal and the other programme workpackages will allow us to identify aspects of the NW European shelf system which may be susceptible to ongoing or future environmental changes. Such knowledge will provide both enhanced scientific understanding and improved predictive tools for policy makers and other stakeholders.

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  • Funder: UKRI Project Code: NE/K011057/1
    Funder Contribution: 25,455 GBP

    Generation of ocean lithosphere by seafloor spreading at mid-ocean ridges is one of the fundamental geological processes operating on Earth. One of the most important yet most intractable problems is to understand how the magma reservoir beneath ridges generates the lower crust, especially at fast spreading rates. Gabbroic rocks from the lower crust are normally inaccessible, but are exposed tectonically on the flanks of the Hess Deep rift in the Pacific Ocean. IODP Expedition 345 aims to provide a unique suite of lower oceanic crustal samples from this locality that will yield insights into magmatic and tectonic processes involved in seafloor spreading. As part of this endeavour, palaeomagnetic data will be collected from recovered core pieces and will be critical to understanding the evolution of the lower crust at this site. These data will provide valuable information on the direction and strength of magnetization locked into the gabbroic rocks we expect to encounter, providing a marker that can be used to infer the amount of tectonic rotation that has affected the site and insights into the contribution that lower crustal rocks make to marine magnetic anomalies. In addition, we intend to use a combination of palaeomagnetic data and geophysical images of the inside of borehole walls to reorient some of the core pieces recovered by drilling, thereby allowing other directional properties (e.g. structural data) to be restored to the correct geographical reference frame.

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  • Funder: UKRI Project Code: NE/K002430/1
    Funder Contribution: 68,520 GBP

    The proposal aims to advance our understanding and predictions of interactions between hydrology and nutrient transfers in headwater catchments in the UK, under climate and land use change scenarios to 2050, using the very latest data and modeling approaches available for the UK. The study catchments will be the UK Demonstration Test Catchments (DTCs) and the aims will be achieved through: (1) using existing climate model scenarios to set baseline outcomes for change; (2) localized DTC-focused stakeholder elicitation workshops to develop scenarios for land use changes in response to the climate scenarios; (3) simulating current hydrological events and future changes in catchment hydrology in response to changing climate/land use; (4) new understanding of phosphorus (P) behaviour in extreme hydrological conditions, using experiments and newly available high resolution observations from the DTCs to inform model development; (5) improved prediction (with uncertainty) of future P behaviour scenarios arising from the new understanding of hydrology-P interactions; (6) attempting to scale up the information from headwater-catchment to full basin scale, and; (7) compare model performance with existing P models and assess uncertainties involved in this process, with further iterations of stakeholder consultation. We shall focus on the 10 km2 scale because this matches the size of the nine study catchments of the Defra DTCs (from the Eden, Wensum and Avon DTCs), which are our chosen study areas; this scale also represents the ideal size for studying processes along the mobilisation-delivery-in-stream impact 'transfer continuum'. These integrated studies will produce a prototype quantitative assessment and prediction of nutrient fluxes. Our hypothesis is that increased seasonal variability in storm patterns (more extreme events, long drought periods), combined with interactions with land use change, will greatly alter future dissolved and particulate P fluxes across the land-water continuum and subsequent retention in-stream and downstream eutrophication risk. We shall extend our initial 'Systems Evidence Based Assessment Methodology (SEBAM)' study that focused on mobilization of P at the farm scale (recently published by the team), into a prototype modeling framework that includes source, mobilization, delivery and in-stream processing functions for predicting P fluxes from UK headwater catchments, and considers land use change, and use this framework (combined with knowledge from other projects involving the team) to scale up our information to define the potential for predicting other nutrient behaviours at the full basin scale. We will capitalize on the new and unique high quality, high temporal resolution P monitoring data that is starting to emerge from the nine Defra DTC sub-catchments. A unique and exciting aspect of the work will be the use of expert elicitation procedures that incorporate fuzzy uncertainty-based analyses to develop tailored land use scenarios (building on the UK Land Use Foresight Initiative) for each of the unique landscape typologies for the 9 DTC focus catchments. Combining this information with the latest climate scenarios for the UK, we will include new developments in high-resolution numerical weather prediction. We shall then use these scenarios to study the impacts of climate and land use change to 2050 on hydrology, P mobilization, delivery and in-stream processing, informed from new empirical learning and experimentation. Model outputs will then be validated for other catchments in the wider UK (Conwy, Ribble, Tarland) using data from linked projects and our partners. Throughout the project, the outcomes will be tested with stakeholders. This will deliver a locally owned knowledge-based framework for understanding and managing future nutrient transfers from rural catchment systems, and some exciting new science on P transfers.

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  • Funder: UKRI Project Code: NE/L000253/1
    Funder Contribution: 406,064 GBP

    The impact of radioactivity on humans and the wider environment is controlled by the behaviour of the radionuclides in groundwaters, soils and sediments, and this behaviour is dictated by the quantities of radionuclides, and their chemical forms. We will study some of the radionuclides which are particularly important because they are potentially present in relatively large quantities, are environmentally mobile, and are readily taken up by living organisms. The main radionuclides we are going to study are: Carbon-14, which occurs in nature, but was produced back in the 1950s and 60s through nuclear weapons testing, and is also present in nuclear wastes; and Uranium (together with its decay product radium) which is present in nature, and also in some nuclear wastes. We will use four areas of the UK which contain elevated levels of these radionuclides as our study sites. These are South Terras (an old uranium mine in Cornwall), the Needle's Eye (a uranium mineral vein in SW Scotland), the Esk Estuary in NW England, and offshore sediments in the NE Irish Sea. At these last two sites, the sediments contain elevated levels of radioactivity from authorised Sellafield discharges, mainly in the 1970s. As well as studying how radioactivity occurs in, and moves through, the soils, waters, plants and (in the offshore sediments) animals, we want to understand the environmental and biological processes which control this movement. To do this, we will do a series of laboratory experiments, looking at the way soil/sediment conditions influence the radionuclide concentrations in solution, the form of the radionuclides in the solution, the way radionuclides are taken up into plants and animals, and the way they are distributed in plant tissues. We will use the results from our field and laboratory studies to develop and test mathematical models of radionuclide transport and transfer processes. These are important because they allow us to predict behaviour, rather than having to make measurements. These predictive models can be used in assessing environmental impacts, cleaning up contaminated land and predicting the long term impact of radioactive waste disposals.

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  • Funder: UKRI Project Code: NE/K00459X/1
    Funder Contribution: 49,606 GBP

    Many conservation organisations have initiatives for protecting plants and animals which operate at the landscape scale. For example there are currently 110 Living Landscape Initiatives (Wildlife Trusts), 40 Futurescapes (RSPB), and 8 Integrated Biodiversity Delivery Areas (Natural England), plus the Nature Improvement Areas (Defra). Food webs are very useful tool for studying communities of plants and animals and over a decade they have developed from simple descriptions of communities, to tools that can predict the results of environmental changes, such as global warming or species loss. Despite the strong move to landscape-level conservation though, food web studies are almost invariably conducted in small plots (e.g. 100 m2) in single habitats, to investigate, for example, pests and their natural enemies in a crop field, or pollinators and their nectar plants in a meadow. Our aim here is to initiate a major change in the way we study food webs by working at the scale of the landscape (defined as a mosaic of different habitats). This proposal will allow us for the first time to understand how food webs interact in real world landscapes and how the various habitats (e.g. woodlands vs heathland vs salt marsh) affect the structure of landscape food webs, and delivery of ecosystem services such as pest control and pollination. Our pilot data suggest that a mosaic of habitats is likely to be more resilient in to environmental damage than individual habitats. Similarly we predict better delivery of ecosystem services if a mixture of habitats are conserved. There is considerable opportunity for win : win scenarios here - better conservation of wildlife and better provision of pollination and pest control, the latter being critical for food security. There are five objectives in our proposal: Objective 1: Time is money in practical conservation biology, and networks which are more efficient to construct (i.e. cheaper!) are more likely to be used by conservation biologists. We will test whether food webs based on reduced sampling can still be used to identify the functionally most important species (i.e. those that support the most other species). Objective 2: We will test whether landscapes composed of multiple habitats are more resilient to species loss than landscapes composed of fewer habitats. Objective 3: Species that move between habitats are rarely considered in practical conservation, but could be critical for ecosystem resilience as they effectively "glue" the various habitats together. We will develop new mathematical tools to calculate how separate the various habitats are in a landscape, and conversely, how well they are glued together. Objective 4: If nature reserves are adjacent to farmland, there is potential for the former to provide ecosystem services to the latter via mobile pollinators and parasitoids. We will test whether pollination and pest control improve in patches of strawberry plants as the number of adjacent natural habitats increases. Objective 5: We will publish our findings in scientific journals and convey them to a wider audience, by: a) running three workshops for 90 nature reserve managers; b) working with the Bee Guardian Foundation to turn five towns in England into Bee Guardians; c) commissioning final year students to write reports for practitioners; d) running a blog; e) communicating findings to influential policy-makers. The research team has the skills and experience to conduct research which will improve landscape conservation projects significantly. Led by Memmott, the team consists of ecologists and computer scientists, museum taxonomists and conservation ecologists. The latter all have long-term interests and influence in multiple landscape conservation projects and as can be seen from the letters of support, our project will provide the information that practitioners need for evidence-based landscape conservation.

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  • Funder: UKRI Project Code: NE/K004697/1
    Funder Contribution: 435,600 GBP

    In 1992 John Gray wrote a now famous book 'Men are from Mars, Women are from Venus' (Harper Collins). In this he illustrated the many differences between males and females using the book title as the central metaphor. He imagined that the sexes are so different that one might as well consider them as originating from different planets. One of the main ideas in the book is that men and women assess or 'score' the currency of their relationship - but that they score according to different scales! This is evident, Gray suggests, when the amount of give and take within a relationship is not assessed or scored equitably. This can lead to a perceived or actual imbalance in the relationship, leading to resentment and so on. Overall, the ideas in this book proved to be a popular way of thinking about how relationships work - or not - in terms of sex differences. Whatever one thinks about the book and its legacy, the central ideas described above accord surprisingly well with evidence drawn from plants and animals. It was realised in the 1970s, for example, that rather than being co-operative ventures, the interactions between the sexes over reproduction are often characterized by conflict rather than co-operation. Hence the sexes often 'disagree' about how much energy and resources to invest in reproduction and how often to make that investment. A good example is evolutionary disagreements over how often to mate. Males often gain from mating frequently and females often do not. Furthermore, females often suffer significantly reduced lifespan from mating too frequently (an effect that we now know is also true in humans). Such lifespan reduction arising from mating frequently is not incurred to anything like the same degree in males. It has recently been realised that these sexual interactions, i.e. the effect of males on female lifespan and vice versa, could actually underlie an important and long-standing puzzle: why it is that males and females often have very different longevity. For example, human females generally live at least 4 years longer than men. Such sex differences are also extremely common in the animal world, and can occur in either direction. In experimental settings the way that lifespan is measured, and longevity 'genes' identified, is often to use non-reproductive individuals, or those that are mated early in life and then kept away from the other sex. Such tests are therefore missing something important - the effects of regular exposure to the other sex. It is now believed that the 'sexual conflicts' of the sort described by Gray and earlier considered by evolutionary biologists such as Geoff Parker, Richard Dawkins and Bill Rice can go a long way to explaining sex differences in lifespan and ageing by considering the effects of one sex upon the other. The central aim of the research proposed here is to evaluate this idea and to examine the underlying genetic basis of the differences in these necessary, but sometimes dangerous, liaisons between the sexes. The work is important because it will be the first full test of these ideas and the first to probe the genomic basis of sex differences caused by sexual conflict. Our proof of principle data gathered for this proposal show that the methods proposed can identify novel ageing genes. The work is also useful because these ideas can also be fed directly into husbandry practices for pest control in the applied sector. Overall this is an exciting and novel project that will test whether sexual conflict can lead to increased ageing and will identify the underlying genes that are responsible.

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  • Funder: UKRI Project Code: NE/K006185/1
    Funder Contribution: 60,924 GBP

    Methane is the second most important greenhouse gas and contributes to the atmospheric chemistry affecting ozone. Southern tropical methane sources and sinks constitute a significant component of the global methane budget. The current major anomaly in southern methane growth rate is among the largest on record. Yet despite its importance, tropical methane variability has received relatively little study. This proposal is to investigate the southern tropical methane budget. The work will improve quantification of southern tropical sources and the understanding of the mechanisms of sudden growth events. Southern tropical methane sources are varied, each having their own isotopic signature in the methane they produce. Wetlands are very extensive in southern tropical S. America and in western parts of southern sub-equatorial Africa, but data on methane emissions from these wetlands are very sparse. Fires in savanna grasslands in Africa and S. America are also significant sources, as are the large ruminant animal populations. Anthropogenic sources are also increasing, with major recent hydrocarbon discoveries. Tropical OH is the major global methane sink. Ascension Is. is a uniquely located, UK-administered, experimental site for studying the methane budget. At surface the air is almost always SE Trade wind, which arrives from the South Atlantic middle latitudes, and, after Ascension, becomes the background air for Amazonia. Above the trade wind inversion, the air over Ascension is tropical, its origin switching regularly between Africa and S. America. Currently Royal Holloway sustains continuous high-precision CH4 and CO2 measurement (CRDS instrument) and also flask measurement of d13C in CH4 on Ascension, as well as on E. Falkland Is. and on RRS JC Ross. Methodologically, the project will focus on the measurement of methane in the southern tropics, carrying out campaign studies, especially on Ascension, and modelling the results. Measurement will include continuous measurement by CRDS in Ascension, E. Falklands, bi-annual Atlantic transects by RRS JC Ross, and Tedlar bag sample collection for CH4 and d13C of CH4 in Uganda, Peru and Bolivia. Campaign studies will include installation of a CRDS instrument in Peru and use of an unmanned aerial system (UAV) to sample above the Trade Wind Inversion on Ascension, as well as source campaigns to characterise d13C signatures of CH4 emissions in Africa and S. America. The proposed helicopter UAV deployment exploits new expertise and would represent an important UK deployment of a substantial UAV for atmospheric sampling. This deployment therefore addresses one of the key science challenges set out in the NERC scoping study for next-generation platforms for Earth & Environmental Science. Modelling studies are also state-of-the-art, and will include regional trajectory analysis to assess source inputs across Africa and S. America, and global modelling of d13C of CH4, tested against the measurements made in the project. The results will be used to assess the importance of southern tropical methane in the global budget, the causes of rapid past changes, and the possibility of future rapid growth in emissions.

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