Biodiversity

Biodiversity is the variability of <a href="/facts/Life/DNw7NUId">life on Earth</a>. It can be measured on various levels. There is for example <a href="/facts/Genetic_variability/Fvcqh60e">genetic variability</a>, <a href="/facts/Species_diversity/jgUGx4UC">species diversity</a>, <a href="/facts/Ecosystem_diversity/t9uc6uxL">ecosystem diversity</a> and <a href="/facts/Phylogenetics/bw4rsovt">phylogenetic</a> diversity. Diversity is not distributed evenly on <a href="/facts/Earth/HLLmDfj0">Earth</a>. It is greater in the <a href="/facts/Tropics/Iv1es8Ih">tropics</a> as a result of the warm <a href="/facts/Climate/f57XrNFU">climate</a> and high <a href="/facts/Primary_productivity/14RzcF5E">primary productivity</a> in the region near the <a href="/facts/Equator/CjaxbVaN">equator</a>. Tropical forest ecosystems cover less than one-fifth of Earth's terrestrial area and contain about 50% of the world's species. There are <a href="/facts/Latitudinal_gradients_in_species_diversity/dNPYyHjP">latitudinal gradients in species diversity</a> for both marine and terrestrial taxa. 
Since <a href="/facts/Abiogenesis/BvAmLPQP">life began on Earth</a>, six major <a href="/facts/Mass_extinctions/HloJubtR">mass extinctions</a> and several minor events have led to large and sudden drops in biodiversity. The <a href="/facts/Phanerozoic/EKKuYnwl">Phanerozoic</a> aeon (the last 540 million years) marked a rapid growth in biodiversity via the <a href="/facts/Cambrian_explosion/Wg29M7PN">Cambrian explosion</a>. In this period, the majority of <a href="/facts/Multicellular_organism/rk8QBF7o">multicellular</a> <a href="/facts/Phylum/ELT3Jyax">phyla</a> first appeared. The next 400 million years included repeated, massive biodiversity losses. Those events have been classified as <a href="/facts/Mass_extinction/HloJubtR">mass extinction</a> events. In the <a href="/facts/Carboniferous/BRKlkYyd">Carboniferous</a>, <a href="/facts/Carboniferous_rainforest_collapse/Vy6pxKrh">rainforest collapse</a> may have led to a great loss of <a href="/facts/Plant/X5BMDMvS">plant</a> and <a href="/facts/Animal/4b8J33nd">animal</a> life. The <a href="/facts/Permian%25E2%2580%2593Triassic_extinction_event/d8kI8Mfn">Permian–Triassic extinction event</a>, 251 million years ago, was the worst; vertebrate recovery took 30 million years. 
<a href="/facts/Human_impact_on_the_environment/vIAWqfPB">Human activities</a> have led to an ongoing <a href="/facts/Biodiversity_loss/p7xI1P0G">biodiversity loss</a> and an accompanying loss of <a href="/facts/Genetic_diversity/GIymbUr8">genetic diversity</a>. This process is often referred to as <a href="/facts/Holocene_extinction/C1LzDDy7">Holocene extinction</a>, or sixth mass extinction. For example, it was estimated in 2007 that up to 30% of all species will be extinct by 2050. <a href="/facts/Habitat_destruction/pyPMkBCY">Destroying habitats</a> for farming is a key reason why biodiversity is decreasing today. <a href="/facts/Climate_change/rEN4BDE7">Climate change</a> also plays a role. This can be seen for example in the <a href="/facts/Effects_of_climate_change_on_biomes/twsm1MXM">effects of climate change on biomes</a>. This anthropogenic extinction may have started toward the end of the <a href="/facts/Pleistocene/0ya9eUp5">Pleistocene</a>, as some studies suggest that the <a href="/facts/Megafauna/8PukHC5A">megafaunal</a> extinction event that took place around the end of the last ice age partly resulted from overhunting.

Biodiversity open-in-new

Biodiversity