Biodiversity - Biodiversity Wikipedia the free encyclopedia...

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Coral reefs are amongst the most diverse ecosystems on earth. Rainforests are an example of biodiversity on the planet and typically possess a great deal of species diversity. This is the Gambia River in Senegal's Niokolo-Koba National Park. Biodiversity From Wikipedia, the free encyclopedia Biodiversity is the degree of variation of life forms within a given species, ecosystem, biome, or planet. Terrestrial biodiversity tends to be highest at low latitudes near the equator, [1] which seems to be the result of the warm climate and high primary productivity. [2] Marine biodiversity tends to be highest along coasts in the Western Pacific, where sea surface temperature is highest and in mid-latitudinal band in all oceans. [3] Biodiversity generally tends to cluster in hotspots, [4] and has been increasing through time [5][6] but will be likely to slow in the future. [7] Rapid environmental changes typically cause mass extinctions. [8][9][10] One estimate is that <1%-3% of the species that have existed on Earth are extant. [11] Since life began on Earth, five major mass extinctions and several minor events have led to large and sudden drops in biodiversity. The Phanerozoic eon (the last 540 million years) marked a rapid growth in biodiversity via the Cambrian explosion—a period during which the majority of multicellular phyla first appeared. [12] The next 400 million years included repeated, massive biodiversity losses classified as mass extinction events. In the Carboniferous, rainforest collapse led to a great loss of plant and animal life. [13] The Permian–Triassic extinction event, 251 million years ago, was the worst; vertebrate recovery took 30 million years. [14] The most recent, the Cretaceous–Paleogene extinction event, occurred 65 million years ago and has often attracted more attention than others because it resulted in the extinction of the dinosaurs. [15] The period since the emergence of humans has displayed an ongoing biodiversity reduction and an accompanying loss of genetic diversity. Named the Holocene extinction, the reduction is caused primarily by human impacts, particularly habitat destruction. Conversely, biodiversity impacts human health in a number of ways, both positively and negatively. [16] The United Nations designated 2011-2020 as the United Nations Decade on Biodiversity. Contents 1 Etymology 2 Definitions 3 Distribution 3.1 Latitudinal gradients 3.2 Hotspots 4 Evolution and history 4.1 Evolutionary diversification 5 Biodiversity and ecosystem services Biodiversity - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Biodiversity 1 of 32 28/08/13 9:21 PM
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5.1 The balance of evidence 5.1.1 Services enhanced by biodiversity 5.1.1.1 Provisioning services 5.1.1.2 Regulating services 5.1.2 Services with mixed evidence 5.1.2.1 Provisioning services 5.1.2.2 Regulating services 5.1.3 Services for which biodiversity is a hindrance 5.1.3.1 Provisioning services 5.1.3.2 Regulating services 5.1.4 Services for which there is insufficient data to draw conclusions 5.1.4.1 Provisioning services 5.1.4.2 Regulating services 5.2 Biodiversity and agriculture 5.3 Biodiversity and human health
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