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Genetic Erosion
Genetic erosion (also known as genetic depletion or genomic erosion) is a process where the limited gene pool of an endangered species diminishes even more when reproductive individuals die off before reproducing with others in their endangered low population. The term is sometimes used in a narrow sense, such as when describing the loss of particular alleles or genes, as well as being used more broadly, as when referring to the loss of a phenotype or whole species. Genetic erosion occurs because each individual organism has many unique genes which get lost when it dies without getting a chance to breed. Low genetic diversity in a population of wild animals and plants leads to a further diminishing gene pool – inbreeding and a weakening immune system can then "fast-track" that species towards eventual extinction. By definition, endangered species suffer varying degrees of genetic erosion. Many species benefit from a human-assisted breeding program to keep their population ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Pool
The gene pool is the set of all genes, or genetic information, in any population, usually of a particular species. Description A large gene pool indicates extensive genetic diversity, which is associated with robust populations that can survive bouts of intense selection. Meanwhile, low genetic diversity (see inbreeding and population bottlenecks) can cause reduced biological fitness and an increased chance of extinction, although as explained by genetic drift new genetic variants, that may cause an increase in the fitness of organisms, are more likely to fix in the population if it is rather small. When all individuals in a population are identical with regard to a particular phenotypic trait, the population is said to be 'monomorphic'. When the individuals show several variants of a particular trait they are said to be polymorphic. History The Russian geneticist Alexander Sergeevich Serebrovsky first formulated the concept in the 1920s as ''genofond'' (gene fund), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Recombination
Genetic recombination (also known as genetic reshuffling) is the exchange of genetic material between different organisms which leads to production of offspring with combinations of traits that differ from those found in either parent. In eukaryotes, genetic recombination during meiosis can lead to a novel set of genetic information that can be further passed on from parents to offspring. Most recombination occurs naturally and can be classified into two types: (1) ''interchromosomal'' recombination, occurring through independent assortment of alleles whose loci are on different but homologous chromosomes (random orientation of pairs of homologous chromosomes in meiosis I); & (2) ''intrachromosomal'' recombination, occurring through crossing over. During meiosis in eukaryotes, genetic recombination involves the pairing of homologous chromosomes. This may be followed by information transfer between the chromosomes. The information transfer may occur without physical exchange (a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Fragmentation
Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological processes that slowly alter the layout of the physical environment (suspected of being one of the major causes of speciation), and human activity such as land conversion, which can alter the environment much faster and causes the extinction of many species. More specifically, habitat fragmentation is a process by which large and contiguous habitats get divided into smaller, isolated patches of habitats. Definition The term habitat fragmentation includes five discrete phenomena: * Reduction in the total area of the habitat * Decrease of the interior: edge ratio * Isolation of one habitat fragment from other areas of habitat * Breaking up of one patch of habitat into several smaller patches * Decrease in the average size of each patch of habit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildlife Corridor
A wildlife corridor, also known as a habitat corridor, or green corridor, is a designated area habitat (ecology), that connects wildlife populations that have been separated by human activities or structures, such as development, roads, or land clearings. These corridors enable movement of individuals between populations, which helps to prevent negative effects of inbreeding and reduced genetic diversity, often caused by genetic drift, that can occur in isolated populations. Additionally, corridors support the re-establishment of populations that may have been reduced or wiped out due to Stochastic process, random events like fires or disease. They can also mitigate some of the severe impacts of habitat fragmentation, a result of urbanization that divides habitat areas and restricts animal movement. Habitat fragmentation from human development poses an increasing threat to biodiversity, and habitat corridors help to reduce its harmful effects. Corridors aside from their benefit t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecosystem
An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and energy flows. Ecosystems are controlled by external and internal Environmental factor, factors. External factors—including climate—control the ecosystem's structure, but are not influenced by it. By contrast, internal factors control and are controlled by ecosystem processes; these include decomposition, the types of species present, root competition, shading, disturbance, and succession. While external factors generally determine which Resource (biology), resource inputs an ecosystem has, their availability within the ecosystem is controlled by internal factors. Ecosystems are wikt:dynamic, dynamic, subject to periodic disturbances and always in the process of recovering from past disturbances. The tendency of an ecosystem to remain clo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Park
A national park is a nature park designated for conservation (ethic), conservation purposes because of unparalleled national natural, historic, or cultural significance. It is an area of natural, semi-natural, or developed land that is protected and owned by a government. Although governments hold different standards for national park designation, the conservation of 'wild nature' for posterity and as a symbol of national pride is a common motivation for the continued protection of all national parks around the world. National parks are almost always accessible to the public.Gissibl, B., S. Höhler and P. Kupper, 2012, ''Civilizing Nature, National Parks in Global Historical Perspective'', Berghahn, Oxford Usually national parks are developed, owned and managed by national governments, though in some countries with federal government, federal or Devolution, devolved forms of government, "national parks" may be the responsibility of subnational, regional, or local authorities. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildlife Sanctuaries
A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, funga, or features of geological or other special interest, which is reserved and managed for purposes of conservation and to provide special opportunities for study or research. They may be designated by government institutions in some countries, or by private landowners, such as charities and research institutions. Nature reserves fall into different IUCN categories depending on the level of protection afforded by local laws. Normally it is more strictly protected than a nature park. Various jurisdictions may use other terminology, such as ecological protection area or private protected area in legislation and in official titles of the reserves. History Cultural practices that roughly equate to the establishment and maintenance of reserved areas for animals dat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Resources
Genetic resources are genetic material of actual or potential value, where genetic material means any material of plant, animal, microbial genetics, microbial or other origin containing functional units of heredity. Genetic resources is one of the three levels of biodiversity defined by the Convention on Biological Diversity in Rio, 1992. __NOTOC__ Examples *Animal genetic resources for food and agriculture *Forest genetic resources *Germplasm, genetic resources that are preserved for various purposes such as breeding, preservation, and research *Plant genetic resources *Genetic resources conservation and sustainable use See also *Cryoconservation of animal genetic resources, a strategy to preserve genetic resources cryogenically *Commission on Genetic Resources for Food and Agriculture, the only permanent intergovernmental body that addresses biological diversity for food and agriculture *International Treaty on Plant Genetic Resources for Food and Agriculture, an internationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Genetic Resources For Food And Agriculture
Animal genetic resources for food and agriculture (AnGR), also known as farm animal genetic resources or livestock biodiversity, are genetic resources (i.e., genetic material of actual or potential value) of avian and mammalian species, which are used for food and agriculture purposes. AnGR is a subset of and a specific element of agricultural biodiversity. AnGR could be embodied in live populations or in conserved genetic materials such as cryoconserved semen or embryos. The diversity of animal genetic resources includes diversity at species, breed and within-breed level. Known are currently 8,800 different breeds of birds and mammals within 38 species used for food and agriculture.FAO. 2015The Second Report on the State of the World's Animal Genetic Resources for Food and Agriculture. Section A, p 5. Rome The main animal species used for food and agriculture production are cattle, sheep, goats, chickens and pigs. In the livestock world, these species are often referred to as " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overgrazing
Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature reserves. It can also be caused by immobile, travel restricted populations of native or non-native wild animals. Overgrazing reduces the usefulness, productivity and biodiversity of the land and is one cause of desertification and erosion. Overgrazing is also seen as a cause of the spread of invasive species of non-native plants and of weeds. Degrading land, emissions from animal agriculture and reducing the biomass in a ecosystem contribute directly to climate change between grazing events. Successful planned grazing strategies have been in support of the American bison of the Great Plains, or migratory wildebeest of the African savannas, or by holistic planned grazing. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Environmental Degradation
Environment most often refers to: __NOTOC__ * Natural environment, referring respectively to all living and non-living things occurring naturally and the physical and biological factors along with their chemical interactions that affect an organism or a group of organisms Other physical and cultural environments *Ecology, the branch of ethology that deals with the relations of organisms to one another and to their physical surroundings *Environment (systems), the surroundings of a physical system that may interact with the system by exchanging mass, energy, or other properties. *Built environment, constructed surroundings that provide the settings for human activity, ranging from the large-scale civic surroundings to the personal places *Social environment, the culture that an individual lives in, and the people and institutions with whom they interact *Market environment, business term Arts, entertainment and publishing * Environment (magazine), ''Environment'' (magazine), a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population Pressure
Population pressure, a term summarizing the stress brought about by an excessive population density and its consequences, is used both in conjunction with human overpopulation and with other animal populations that suffer from too many individuals per area (or volume in the case of aquatic organisms). In the case of humans, absolute numbers of individuals may lead to population pressure, but the same is true for overexploitation and overconsumption of available resources and ensuing environmental degradation by otherwise-normal population densities. Similarly, when the carrying capacity of the environment goes down, unchanged population numbers may prove too high and again produce significant pressure. Governments and international organizations have responded to increasing population pressure by implementing a range of policy measures that include family planning programs, investments in healthcare and education, and efforts to improve gender equality. These interventions aim to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
