Extinction
This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence.[7] Notable extinct animal species include non-avian dinosaurs, palaeotheres, saber-toothed cats, dodos, mammoths, ground sloths, thylacines, trilobites, golden toads, and passenger pigeons.[15] A 2018 report indicated that the phylogenetic diversity of 300 mammalian species erased during the human era since the Late Pleistocene would require 5 to 7 million years to recover.[17][18][19] In a subsequent report, IPBES listed unsustainable fishing, hunting and logging as being some of the primary drivers of the global extinction crisis.The main cause of the extinctions is the destruction of natural habitats by human activities, such as cutting down forests and converting land into fields for farming.Species listed under this status by the International Union for Conservation of Nature (IUCN) are not known to have any living specimens in the wild and are maintained only in zoos or other artificial environments.A 2018 study indicated that the sixth mass extinction started in the Late Pleistocene could take up to 5 to 7 million years to restore mammal diversity to what it was before the human era.The coelacanth, a fish related to lungfish and tetrapods, is an example of a Lazarus taxon that was known only from the fossil record and was considered to have been extinct since the end of the Cretaceous Period.[32] Attenborough's long-beaked echidna (Zaglossus attenboroughi) is an example of a Lazarus species from Papua New Guinea that had last been sighted in 1962 and believed to be possibly extinct, until it was recorded again in November 2023.Population bottlenecks can dramatically reduce genetic diversity by severely limiting the number of reproducing individuals and make inbreeding more frequent.Extinction is likeliest for rare species coming into contact with more abundant ones;[48] interbreeding can swamp the rarer gene pool and create hybrids, depleting the purebred gene pool (for example, the endangered wild water buffalo is most threatened with extinction by genetic pollution from the abundant domestic water buffalo).Recently in geological time, humans have become an additional cause of extinction of some species, either as a new mega-predator or by transporting animals and plants from one part of the world to another.Such introductions have been occurring for thousands of years, sometimes intentionally (e.g. livestock released by sailors on islands as a future source of food) and sometimes accidentally (e.g. rats escaping from boats).[63] There have been at least five mass extinctions in the history of life on earth, and four in the last 350 million years in which many species have disappeared in a relatively short period of geological time."[69] Biologist E. O. Wilson estimated[15] in 2002 that if current rates of human destruction of the biosphere continue, one-half of all plant and animal species of life on earth will be extinct in 100 years.Biologists Paul R. Ehrlich and Stuart Pimm, among others, contend that human population growth and overconsumption are the main drivers of the modern extinction crisis.[75][76][39][77] In January 2020, the UN's Convention on Biological Diversity drafted a plan to mitigate the contemporary extinction crisis by establishing a deadline of 2030 to protect 30% of the Earth's land and oceans and reduce pollution by 50%, with the goal of allowing for the restoration of ecosystems by 2050.[80] The report warned that biodiversity will continue to decline if the status quo is not changed, in particular the "currently unsustainable patterns of production and consumption, population growth and technological developments".They added that failure of the global community to reach these targets is hardly surprising given that biodiversity loss is "nowhere close to the top of any country's priorities, trailing far behind other concerns such as employment, healthcare, economic growth, or currency stability.As a result, the scientific community embarked on a voyage of creative rationalization, seeking to understand what had happened to these species within a framework that did not account for total extinction.In October 1686, Robert Hooke presented an impression of a nautilus to the Royal Society that was more than two feet in diameter,[90] and morphologically distinct from any known living species.[87] Similarly, in 1695, Sir Thomas Molyneux published an account of enormous antlers found in Ireland that did not belong to any extant taxa in that area.When parts of the world had not been thoroughly examined and charted, scientists could not rule out that animals found only in the fossil record were not simply "hiding" in unexplored regions of the Earth.[92] Georges Cuvier is credited with establishing the modern conception of extinction in a 1796 lecture to the French Institute,[85][89] though he would spend most of his career trying to convince the wider scientific community of his theory.Instead of the catastrophic floods inferred by Cuvier, Lyell demonstrated that patterns of saltwater and freshwater deposits, like those seen in the Paris basin, could be formed by a slow rise and fall of sea levels.[103][104] Biogeographer Jared Diamond notes that while big business may label environmental concerns as "exaggerated", and often cause "devastating damage", some corporations find it in their interest to adopt good conservation practices, and even engage in preservation efforts that surpass those taken by national parks.People who live close to nature can be dependent on the survival of all the species in their environment, leaving them highly exposed to extinction risks.[110] Anthropologist Jason Hickel speculates that the reason humanity seems largely indifferent to anthropogenic mass species extinction is that we see ourselves as separate from the natural world and the organisms within it.In addition, anti-malarial and mosquito control programs offer little realistic hope to the 300 million people in developing nations who will be infected with acute illnesses this year.[124] This attempt failed: of the 285 embryos reconstructed, 54 were transferred to 12 Spanish ibexes and ibex–domestic goat hybrids, but only two survived the initial two months of gestation before they, too, died.
Extinct (disambiguation)Extinction (disambiguation)Lists of extinct speciesthylacinespeciesPalaeotheriumhominidsConservation statusExtinct in the Wild (EW)ThreatenedCritically Endangered (CR)Endangered (EN)Vulnerable (VU)Lower RiskNear Threatened (NT)Conservation Dependent (CD)Least Concern (LC)Data Deficient (DD)Not Evaluated (NE)International Union forConservation of Nature (IUCN)IUCN Red ListNatureServe statusLists of organisms by populationEvolutionary biologyDarwin's finchesJohn GouldIntroductionOutlineGlossaryEvidenceHistoryPopulation geneticsVariationDiversityMutationNatural selectionAdaptationPolymorphismGenetic driftGene flowSpeciationAdaptive radiationCo-operationCoevolutionCoextinctionContingencyDivergenceConvergenceParallel evolutionOrigin of lifeCommon descentHistory of lifeTimeline of evolutionHuman evolutionRecent human evolutionPhylogenyBiodiversityBiogeographyClassificationEvolutionary taxonomyCladisticsTransitional fossilExtinction eventOverviewRenaissanceBefore DarwinDarwinOrigin of SpeciesBefore synthesisModern synthesisMolecular evolutionEvo-devoCurrent researchHistory of speciationHistory of paleontologytimelineApplications of evolutionBiosocial criminologyEcological geneticsEvolutionary aestheticsEvolutionary anthropologyEvolutionary computationEvolutionary ecologyEvolutionary economicsEvolutionary epistemologyEvolutionary ethicsEvolutionary game theoryEvolutionary linguisticsEvolutionary medicineEvolutionary neuroscienceEvolutionary physiologyEvolutionary psychologyExperimental evolutionInvasion geneticsIsland biogeographyPhylogeneticsPaleontologySelective breedingSpeciation experimentsSociobiologySystematicsUniversal DarwinismEugenicsEvolution as fact and theoryDysgenicsSocial effectsCreation–evolution controversyTheistic evolutionObjections to evolutionLevel of supportNature-nurture controversylast memberfunctionally extinctreproduceLazarus taxafossil recordeukaryotesmicroorganismsbacterianon-avian dinosaurspalaeotheressaber-toothed catsmammothsground slothsthylacinestrilobites