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Ecology
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Ecology (from Greek: οἶκος, "house", or "environment"; -λογία, "study of") is a branch of biology that studies the interactions among organisms and their biophysical environment, which includes both biotic and abiotic components. Topics of interest include the biodiversity, distribution, biomass, and populations of organisms, as well as cooperation and competition within and between species. Ecosystems are dynamically interacting systems of organisms, the communities they make up, and the non-living components of their environment. Ecosystem processes, such as primary production, pedogenesis, nutrient cycling, and niche construction, regulate the flux of energy and matter through an environment. These processes are sustained by organisms with specific life history traits.

Ecology is not synonymous with environmentalism, natural history, or environmental science. It overlaps with the closely related sciences of evolutionary biology, genetics, and ethology. An important focus for ecologists is to improve the understanding of how biodiversity affects ecological function. Ecologists seek to explain:

  • Life processes, interactions, and adaptations
  • The movement of materials and energy through living communities
  • The successional development of ecosystems
  • The abundance and distribution of organisms and biodiversity in the context of the environment.

Ecology has practical applications in conservation biology, wetland management, natural resource management (agroecology, agriculture, forestry, agroforestry, fisheries), city planning (urban ecology), community health, economics, basic and applied science, and human social interaction (human ecology). For example, the Circles of Sustainability approach treats ecology as more than the environment 'out there'. It is not treated as separate from humans. Organisms (including humans) and resources compose ecosystems which, in turn, maintain biophysical feedback mechanisms that moderate processes acting on living (biotic) and non-living (abiotic) components of the planet. Ecosystems sustain life-supporting functions and produce natural capital like biomass production (food, fuel, fiber, and medicine), the regulation of climate, global biogeochemical cycles, water filtration, soil formation, erosion control, flood protection, and many other natural features of scientific, historical, economic, or intrinsic value.

The word "ecology" ("Ökologie") was coined in 1866 by the German scientist Ernst Haeckel. Ecological thought is derivative of established currents in philosophy, particularly from ethics and politics. Ancient Greek philosophers such as Hippocrates and Aristotle laid the foundations of ecology in their studies on natural history. Modern ecology became a much more rigorous science in the late 19th century. Evolutionary concepts relating to adaptation and natural selection became the cornerstones of modern ecological theory.

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The hierarchy of biological classification's eight major taxonomic ranks, which is an example of definition by genus and differentia. Life is divided into domains, which are subdivided into further groups. Intermediate minor rankings are not shown.
Pictured left: The hierarchy of biological classification's eight major taxonomic ranks, which is an example of definition by genus and differentia. Life is divided into domains, which are subdivided into further groups. Intermediate minor rankings are not shown.

Life (cf. biota) is a characteristic that distinguishes objects that have signaling and self-sustaining processes (i. e., living organisms) from those that do not, either because such functions have ceased (death), or else because they lack such functions and are classified as inanimate. Biology is the science concerned with the study of life.

Living organisms undergo metabolism, maintain homeostasis, possess a capacity to grow, respond to stimuli, reproduce and, through natural selection, adapt to their environment in successive generations. More complex living organisms can communicate through various means. A diverse array of living organisms (life forms) can be found in the biosphere on Earth, and the properties common to these organisms—plants, animals, fungi, protists, archaea, and bacteria—are a carbon- and water-based cellular form with complex organization and heritable genetic information.

It is still a challenge for scientists and philosophers to define life in unequivocal terms. Defining life is difficult—in part—because life is a process, not a pure substance. Any definition must be sufficiently broad to encompass all life with which we are familiar, and it should be sufficiently general that, with it, scientists would not miss life that may be fundamentally different from life on Earth.

Evidence suggests that life on Earth has existed for about 3.7 billion years, with the oldest traces of life found in fossils dating back 3.4 billion years. All known life forms share fundamental molecular mechanisms, and based on these observations, theories on the origin of life attempt to find a mechanism explaining the formation of a primordial single cell organism from which all life originates. There are many different hypotheses regarding the path that might have been taken from simple organic molecules via pre-cellular life to protocells and metabolism. Many models fall into the "genes-first" category or the "metabolism-first" category, but a recent trend is the emergence of hybrid models that combine both categories.

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Carbon cycle-cute diagram.jpeg
Credit: NASA

The carbon cycle is the biogeochemical cycle by which carbon is exchanged between the biosphere, geosphere, hydrosphere, and atmosphere of the Earth. Burning fossil fuels leads to the addition of extra carbon into the cycle over what naturally occurs and is a major cause of climate change.

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Aziz Nacib Ab'Sáber (born October 24, 1924) is an environmentalist and one of Brazil´s most respected scientists, honored with the highest awards of Brazilian science in geography, geology, ecology and archaeology. Graduated in geography, he is a former president and current honororary president of the SBPC (Brazilian Society for the Advancement of Science), Emeritus Professor of the University of São Paulo and member of the highest rank - Order Grão-Cruz in Earth Sciences - of the Academy of Science.

The contributions of Ab`Saber to science range from the first research of oil camps in Brazil's northeast to surveys of Brazil's natural realms and the restoration of the history of forests, camps and primitive humans over geologic time in South America. He made central contributions to biology, South American archaeology, and to Brazilian ecology, geology and geography.

Ab'Sáber was the first person to classify scientifically the Brazilian and South-America territory in morphoclimatic domains. He also contributed to the "Pleistocene refuge hypothesis", an attempt to explain the distribution of Neotropical taxa as a function of their isolation in forest fragments during glacial periods, which allowed populations to speciate.

Did you know...

Coptotermes formosanus shiraki USGov k8204-7.jpg
...in many cultures, termites (particularly the winged ones known as alates) are used for food?

(Pictured left: Formosan subterranean termites)

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U.S. consumers and industry dispose of enough aluminum to rebuild the commercial air fleet every three months; enough iron and steel to continuously supply all automakers; enough glass to fill New York's World Trade Center every two weeks.


Environmental Defense Fund advertisement, The Christian Science Monitor, 1990

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The Journal of Applied Ecology is a peer-reviewed scientific journal publishing research in all areas of environmental management. It began publication in 1964 and is the third oldest journal of the British Ecological Society (after the Journal of Ecology and the Journal of Animal Ecology). It is available both in print and online.

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