24 research outputs found

    The role of visual adaptation in cichlid fish speciation

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    D. Shane Wright (1) , Ole Seehausen (2), Ton G.G. Groothuis (1), Martine E. Maan (1) (1) University of Groningen; GELIFES; EGDB(2) Department of Fish Ecology & Evolution, EAWAG Centre for Ecology, Evolution and Biogeochemistry, Kastanienbaum AND Institute of Ecology and Evolution, Aquatic Ecology, University of Bern.In less than 15,000 years, Lake Victoria cichlid fishes have radiated into as many as 500 different species. Ecological and sexual sel ection are thought to contribute to this ongoing speciation process, but genetic differentiation remains low. However, recent work in visual pigment genes, opsins, has shown more diversity. Unlike neighboring Lakes Malawi and Tanganyika, Lake Victoria is highly turbid, resulting in a long wavelength shift in the light spectrum with increasing depth, providing an environmental gradient for exploring divergent coevolution in sensory systems and colour signals via sensory drive. Pundamilia pundamila and Pundamilia nyererei are two sympatric species found at rocky islands across southern portions of Lake Victoria, differing in male colouration and the depth they reside. Previous work has shown species differentiation in colour discrimination, corresponding to divergent female preferences for conspecific male colouration. A mechanistic link between colour vision and preference would provide a rapid route to reproductive isolation between divergently adapting populations. This link is tested by experimental manip ulation of colour vision - raising both species and their hybrids under light conditions mimicking shallow and deep habitats. We quantify the expression of retinal opsins and test behaviours important for speciation: mate choice, habitat preference, and fo raging performance

    Proceedings of the International Conference on Genetic Improvement of Sorghum and Pearl Millet

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    In 1971, an international symposium, Sorghum in the Seventies , organized by the All India Coordinated Sorghum Improvement Project with support from the Indian Council of Agricultural Research and the Rockefeller Foundation was held in Hyderabad, India. The symposium reviewed the current knowledge base of the scientific, production and nutritional aspects of sorghum as a crop and as a human food. In 1981, ICRISAT, INTSORMIL, and the Indian Council of Agricultural Research (ICAR) sponsored Sorghum in the Eighties , an international symposium at ICRISAT Center in India, to review the achievements accomplished in sorghum research during the preceding 10 years. They reviewed sorghum\u27s role as an important cereal food, feed, construction material, and fuel in the developed and developing countries. In 1994, after discussion among INTSORMIL and ICRISAT scientists, it was recognized that an international meeting on the genetic improvement of grain sorghum and pearl millet was needed and would be strongly supported by the international sorghum and millet research community. Those discussions led to the September 1996 International Conference on Genetic Improvement of Sorghum and Pearl Millet. Grain sorghum and pearl millet are major food grains in the semiarid tropics of Africa, India, and South America. Sorghum ranks fifth among the world\u27s cereals, following wheat, maize, rice, and barley. F AO includes all millets together in its production estimates. Current estimates indicate that annual world sorghum production is approximately 61 million metric tons and world millet production is approximately 20 million metric tons. The inaugural speaker of this 1996 conference, Dr. Leland House, indicated global population is projected to increase to nine billion people by the year 2030 and is projected to increase most rapidly in the developing world. This will create a growing demand for food, as well as potential new market opportunities for food products developed from these basic grains

    Evolution of the northern Australian flora: role of the Sunda-Sahul Floristic Exchange

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    Elizabeth Joyce investigated the Sunda-Sahul Floristic Exchange using floristic, phylogeographic and phylogenomic approaches. She compiled the first preliminary regional plant checklist, found the SSFE had a substantial impact on floristic composition, identified two exchange tracks from Southeast Asia into Australia, and found that in Anacardiaceae (Sapindales) extinction affected SSFE dynamics

    Soil Improving Cropping Systems for Sustainable and Profitable Farming in Europe

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    A major challenge for the future is combining both the profitability and sustainability of agriculture. The European H2020 project SoilCare aims to identify, test, and evaluate soil-improving cropping systems (SICS) which contribute to the implementation of agricultural solutions across Europe (See: https://soilcare-project.eu/en/ for the project website). The project includes 16 study sites distributed across Europe. Each study site implemented short-term experiments during the duration of the project, and most also ran long-term experiments comparing soil quality as a function of different treatments, such as soil amendments, tillage, cover crops, nutrients, and organic matter inputs. In addition, eight work-packages assess different aspects encompassing reviewing the soil-improving cropping systems, the participatory analysis of implementation and selection, methodology and analysis, upscaling at the European level, policy analysis and support, and dissemination and communication. In this way, SoilCare works on a providing a holistic approach to soil quality, spanning from biophysical to human interactions at different scales. In this Special Issue, we aim to compile scientific findings on soil-improving cropping systems (SICS) based on field experiments, including the study of policy, upscaling, and dissemination

    Fire

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    Vegetation plays a crucial role in regulating environmental conditions, including weather and climate. The amount of water and carbon dioxide in the air and the albedo of our planet are all influenced by vegetation, which in turn influences all life on Earth. Soil properties are also strongly influenced by vegetation, through biogeochemical cycles and feedback loops (see Volume 1A—Section 4). Vegetated landscapes on Earth provide habitat and energy for a rich diversity of animal species, including humans. Vegetation is also a major component of the world economy, through the global production of food, fibre, fuel, medicine, and other plantbased resources for human consumptio

    Agroforestry and Sustainable Agricultural Production

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    This book focuses on the potential of agroforestry to maximize agriculture production while minimizing negative effects on the environment. It collects several studies on agroforestry systems from around the world, including a variety of types of agroforestry systems, from traditional wood-pastures to tropical cocoa-based systems, and research approaches, from literature reviews to state-of-the-art ecological-economic models. The book highlights the potential of agroforestry as a promising approach for the creation of multifunctional landscapes able to face contemporary environmental challenges
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