International Union for Conservation of Nature and Natural Resources or IUCN is the regulatory body that deals with biodiversity and the loss of biodiversity.The IUCN Red List makes an assessment of the status of biodiversity to show how vulnerable a species is to get extinct.Biodiversity is a dynamic environmental factor, which keeps changing with the environment and time.As new species may get added as a result of speciation, existing species may become extinct, leading to loss of biodiversity.Adverse human activities may increase the rate at which species become extinct, leading to mass extinctions.IUCN Red List helps to check this drastic loss of biodiversity by introducing conservation strategies for the species which are more likely to get extinct in the near future.Important PointsAccording to IUCN, about 40,000 species are facing the threat of extinction.Analysis has shown that extinctions are not random and some groups of organisms are more vulnerable than the others.The variation of animals facing extinction:Amphibians - 40%Sharks and Rays - 37%Conifers - 34%Coral Reefs - 33%Mammals - 26%Birds - 13%IUCN divides species into 9 categories:Not EvaluatedData DeficientLeast ConcernNear ThreatenedVulnerableEndangeredCritically EndangeredExtinct in the WildExtinctThe "Endangered" and "Critically Endangered" categories include all the species that are currently facing the threat of extinction.Therefore, the highest percentage of endangered species are of amphibians.