Biodiversity: Growth and Extinction

Only available on StudyMode
  • Download(s) : 19
  • Published : May 24, 2013
Open Document
Text Preview
Bio Diversity and it’s loss in growth

Biodiversity is the degree of variation of life forms within a given species, ecosystem, biome, or an entire planet. Biodiversity is a measure of thehealth of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regionssupport fewer species. Rapid environmental changes typically cause mass extinctions. One estimate is that less than 1% of the species that have existed on Earth areextant.[1][verification needed] Since life began on Earth, five major mass extinctions and several minor events have led to large and sudden drops in biodiversity. The Phanerozoiceon (the last 540 million years) marked a rapid growth in biodiversity via the Cambrian explosion—a period during which the majority of multicellularphyla first appeared.[2] The next 400 million years included repeated, massive biodiversity losses classified as mass extinction events. In theCarboniferous, rainforest collapse led to a great loss of plant and animal life.[3] The Permian–Triassic extinction event, 251 million years ago, was the worst; vertebrate recovery took 30 million years.[4] 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.[5] The period since the emergence of humans has displayed an ongoing biodiversity reduction and an accompanying loss of genetic diversity. Named theHolocene 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.[6] The United Nations designated 2011-2020 as the United Nations Decade on Biodiversity.
tracking img