39 research outputs found
Dietary variation and overlap in Central and Northwest European Stephanorhinus kirchbergensis and S. hemitoechus (Rhinocerotidae, Mammalia) influenced by habitat diversity
To trace the dietary evolution of the two abundant Middle to Late Pleistocene rhinoceros species Stephanorhinus kirchbergensis and Stephanorhinus hemitoechus in Europe over several climatic cycles, we examined comprehensive material of stratigraphically well-defined alaeopopulations from different regions and interglacials. Using morphometrics and mesowear analysis, these reconstructions of Stephanorhinus diets indicate that habitat diversity and interspecific competition with closely related rhinoceros species induced variation in feeding behaviour. Although anatomical features of both species suggest significantly higher dietary specializations compared to the Early to early Middle Pleistocene Stephanorhinus hundsheimensis, their mesowear signals are characteristic of a mixed feeder diet, similar to that of extant mammal species in relatively open habitats. Both species retained a degree of dietary flexibility, enabling them to survive in a range of environments. Although each of these rhinoceroses preferred different habitats, species identity alone is not sufficient to establish the real dietary traits of a Stephanorhinus palaeopopulation. As a consequence, their occurrence in a faunal assemblage alone cannot be taken to indicate a specific habitat.
S. kirchbergensis and S. hemitoechus were embedded in a dynamic process of temporo-spatial replacements and interspecific differentiation of rhinoceroses in the western Palaearctic. However, dietary specialization in these Middle to Late Pleistocene European rhinoceroses was not the result of a directed time-transgressive evolution. Rather, within the range of each species' ecological tolerance, it was controlled by environmental parameters, with habitat variability as the main factor
The effect of preparation methods on dung fungal spores: Implications for recognition of megafaunal populations
Spores from coprophilous fungi are emerging as an important palaeoecological indicator of the presence of large herbivores, but the methods by which they are recovered may have a significant impact on their preservation and recognition. Here, we test a number of chemical and mechanical techniques used in palynology. Spore occurrence, size and shape is affected by preparation technique and is particularly affected by acetolysis. This has important implications for recognition of past megafaunal populations
Relating dung fungal spore influx rates to animal density in a temperate environment: Implications for palaeoecological studies
The management of the remainder of Europe’s once extensive forests is hampered by a poor understanding of the character of the vegetation and drivers of change before the onset of clearance for farming. Pollen data indicate a closed-canopy, mixed-deciduous forest, contrasting with the assertion that large herbivores would have maintained a mosaic of open grassland, regenerating scrub and forested groves. Coprophilous fungal spores from sedimentary sequences are increasingly used as a proxy for past herbivore impact on vegetation, but the method faces methodological and taphonomical issues. Using pollen trap data from a long-running experiment in Chillingham Wild Cattle Park, UK, we investigate the first steps in the mechanisms connecting herbivore density to the incorporation of fungal spores in sediments and assess the effects of environmental variables on this relationship. Herbivore utilisation levels correlate with dung fungal spore abundance. Chillingham is densely populated by large herbivores, but dung fungal spore influx is low. Herbivores may thus be present on the landscape but go undetected. The absence of dung fungal spores is therefore less informative than their presence. Dung fungal spores likely enter the sediment record through a different pathway from wind-borne pollen and thus dung fungal abundance is better expressed as influx rates than as percentage of total pollen. Landscape openness, vegetation type and site wetness do not distort the impact of utilisation levels on dung fungal spore representation. However, dung fungal spore influx varies markedly between seasons and years. Spores travel, leading to a background level of spore deposition across the landscape, and at times a depletion of spores, especially under wet weather conditions. Animal behaviour, as well as husbandry practices, can lead to the accumulation of dung, and thus fungal spores, in specific locations on the landscape that do not directly reflect grazing pressure
Multi-proxy evidence for woodland clearance in northeast Northumberland (England) during the Iron Age
Pollen diagrams covering the Bronze Age to Roman period from northeast Northumberland are scarce. We present a 14C-dated pollen record from a peat-filled forest hollow in Chillingham Wild Cattle Park, northeast Northumberland, that spans the Iron Age. For the first time for this part of Northumberland, fungal spores are also analysed to investigate whether clearances took place in the context of crop cultivation or pastoralism. The pollen diagram shows significant woodland cover during the Late Bronze Age, with small-scale landscape openness potentially representing crop cultivation and animal grazing under a tree canopy. A local clearance event, with arboreal pollen falling to 13.2%, is radiocarbon dated to the late Early to Middle Iron Age, likely coinciding with the construction and occupancy of the nearby Ros Castle hillfort. A significant rise in dung fungal spores and the presence of Plantago and other open vegetation taxa indicate animal husbandry played an important role in this clearance phase. A subsequent large decrease in dung fungi and a small rise in arboreal pollen may reflect a degree of abandonment of the area after the climate cooled. Peat formation ceased in the late Middle to Late Iron Age as the hollow filled up. Limited renewed peat growth occurred in the last century or so, after peat shrinkage due to drying and consequent oxidation provided the possibility for renewed peat formation within the hollow
Valuing beyond economics : a pluralistic evaluation framework for participatory policymaking
The sustainability challenges facing societies call for policies and governance systems that are attuned to the diversity of goods that support and enrich human life via ecological, technical and other kinds of systems, and to the plurality of values that people hold across diverse cultures and belief systems. A pluralistic evaluation framework (PEF) is here presented as a tool for considering diverse kinds of goodness as perceived by diverse stakeholders in the design and evaluation of policies or projects. It arises from considering a suite of aspects of meaning (biotic, economic, aesthetic, etc.) at each of three stages, namely: identifying relevant stakeholders, mapping real-world systems and assessing modes of valuing. This framework, drawing on the philosophical work of Herman Dooyeweerd and Dirk Vollenhoven, offers a joined-up, participatory approach to policymaking. We report pilot trials of the PEF with groups of policymakers at a series of workshops, demonstrating that it provides additional perspectives and unification of core issues and can be used in a wide range of areas of policymaking and project assessment. We also illustrate its potential application to a controversial environmental project and outline how a pluralistic evaluation framework can be used in tandem with existing frameworks
Genome-wide association and transcriptome studies identify target genes and risk loci for breast cancer
Genome-wide association studies (GWAS) have identified more than 170 breast cancer susceptibility loci. Here we hypothesize that some risk-associated variants might act in non-breast tissues, specifically adipose tissue and immune cells from blood and spleen. Using expression quantitative trait loci (eQTL) reported in these tissues, we identify 26 previously unreported, likely target genes of overall breast cancer risk variants, and 17 for estrogen receptor (ER)-negative breast cancer, several with a known immune function. We determine the directional effect of gene expression on disease risk measured based on single and multiple eQTL. In addition, using a gene-based test of association that considers eQTL from multiple tissues, we identify seven (and four) regions with variants associated with overall (and ER-negative) breast cancer risk, which were not reported in previous GWAS. Further investigation of the function of the implicated genes in breast and immune cells may provide insights into the etiology of breast cancer.Peer reviewe
Mendelian randomisation study of height and body mass index as modifiers of ovarian cancer risk in 22,588 BRCA1 and BRCA2 mutation carriers.
BackgroundHeight and body mass index (BMI) are associated with higher ovarian cancer risk in the general population, but whether such associations exist among BRCA1/2 mutation carriers is unknown.MethodsWe applied a Mendelian randomisation approach to examine height/BMI with ovarian cancer risk using the Consortium of Investigators for the Modifiers of BRCA1/2 (CIMBA) data set, comprising 14,676 BRCA1 and 7912 BRCA2 mutation carriers, with 2923 ovarian cancer cases. We created a height genetic score (height-GS) using 586 height-associated variants and a BMI genetic score (BMI-GS) using 93 BMI-associated variants. Associations were assessed using weighted Cox models.ResultsObserved height was not associated with ovarian cancer risk (hazard ratio [HR]: 1.07 per 10-cm increase in height, 95% confidence interval [CI]: 0.94-1.23). Height-GS showed similar results (HR = 1.02, 95% CI: 0.85-1.23). Higher BMI was significantly associated with increased risk in premenopausal women with HR = 1.25 (95% CI: 1.06-1.48) and HR = 1.59 (95% CI: 1.08-2.33) per 5-kg/m2 increase in observed and genetically determined BMI, respectively. No association was found for postmenopausal women. Interaction between menopausal status and BMI was significant (Pinteraction ConclusionOur observation of a positive association between BMI and ovarian cancer risk in premenopausal BRCA1/2 mutation carriers is consistent with findings in the general population
Genome-wide association and transcriptome studies identify target genes and risk loci for breast cancer
Genome-wide association studies (GWAS) have identified more than 170 breast cancer susceptibility loci. Here we hypothesize that some risk-associated variants might act in non-breast tissues, specifically adipose tissue and immune cells from blood and spleen. Using expression quantitative trait loci (eQTL) reported in these tissues, we identify 26 previously unreported, likely target genes of overall breast cancer risk variants, and 17 for estrogen receptor (ER)-negative breast cancer, several with a known immune function. We determine the directional effect of gene expression on disease risk measured based on single and multiple eQTL. In addition, using a gene-based test of association that considers eQTL from multiple tissues, we identify seven (and four) regions with variants associated with overall (and ER-negative) breast cancer risk, which were not reported in previous GWAS. Further investigation of the function of the implicated genes in breast and immune cells may provide insights into the etiology of breast cancer