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Constant parameters of homeostasisThese constants are not strictly fixed. There may be some deviation from the average in one way or another in a kind of "corridor". For each parameter limits the maximum possible deviations own. Also, they differ on the time during which the body can tolerate a violation of a specific parameter of homeostasis without any serious consequences. Examples: § The homeostasis constants of animals are the volume, the composition of the blood and other body fluids. § Homeostasis is the maintenance of a population is determined by the spatial structure, density, and genetic diversity. Because of homeostatic regulation is maintained constant composition and populations in the community. § At the ecosystem level homeostasis is manifested in the most stable forms of interaction between the species, which is reflected in the adaptation to the peculiarities of the environment and the maintenance cycles cycling of nutrients.
Historically, ecological succession was seen as having a stable end-stage called the climax sometimes referred to as the 'potential biodiversity' of a site, shaped primarily by the local climate. This idea has been largely abandoned by modern ecologists in favor of non-equilibrium ideas of how ecosystems function, as most natural ecosystems experience disturbance at a rate that makes a "climax" community unattainable.
Picture 3. The Krakatoa In the Gaia hypothesis, James Lovelock stated that the entire mass of living matter on Earth (or any planet with life) functions as a vast homeostatic superorganism that actively modifies its planetary environment to produce the environmental conditions necessary for its own survival. In this view, the entire planet maintains homeostasis. Whether this sort of system is present on Earth is still open to debate. However, some relatively simple homeostatic mechanisms are generally accepted. For example, it is sometimes claimed that when atmospheric carbon dioxide levels rise, certain plants are able to grow better and thus act to remove more carbon dioxide from the atmosphere. However, warming has exacerbated droughts, making water the actual limiting factor on land. When sunlight is plentiful and atmospheric temperature climbs, it has been claimed that the phytoplankton of the ocean surface waters may thrive and produce more dimethyl sulfide, DMS. The DMS molecules act ascloud condensation nuclei, which produce more clouds, and thus increase the atmospheric albedo, and this feeds back to lower the temperature of the atmosphere. However, rising sea temperature has stratified the oceans, separating warm, sunlit waters from cool, nutrient-rich waters. Thus, nutrients have become the limiting factor, and plankton levels have actually fallen over the past 50 years, not risen. As scientists discover more about Earth, vast numbers of positive and negative feedback loops are being discovered, that, together, maintain a metastable condition, sometimes within very broad range of environmental conditions. Environmental pressure, such as competition or change in temperature, can lead to adaptation/extinction of species over time. Conclusions Homeostasis is the property of a system that regulates its internal environment and tends to maintain a stable. It can be either an open or closed system. In simple terms, it is a process in which the body's internal environment is kept stable. Date: 2015-12-11; view: 2471
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