# EDGE of Existence programme > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/EDGE_of_Existence_programme > Markdown URL: https://mediated.wiki/source/EDGE_of_Existence_programme.md > Source: https://en.wikipedia.org/wiki/EDGE_of_Existence_programme > Source revision: 1338512691 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Research and conservation initiative}} right|200px The '''''EDGE of Existence programme''''' is a research and conservation initiative that focuses on species deemed to be the world's most '''Evolutionarily Distinct and Globally Endangered (EDGE) species'''. Developed by the [Zoological Society of London](/source/Zoological_Society_of_London) (ZSL), the programme aims to raise awareness of these species, implement targeted research and conservation actions to halt their decline, and to train in-country conservationists (called EDGE Fellows) to protect them. EDGE species are [animal species](/source/animal_species) which have a high 'EDGE score', a metric combining endangered [conservation status](/source/conservation_status) with the genetic distinctiveness of the particular [taxon](/source/taxon). Distinctive species have few closely related species, and EDGE species are often the only surviving member of their [genus](/source/genus) or even higher [taxonomic rank](/source/taxonomic_rank). The extinction of such species would therefore represent a disproportionate loss of unique evolutionary history and [biodiversity](/source/biodiversity). The EDGE logo is the [echidna](/source/echidna).{{Cite web |last=Sánchez |first=Esther |date=2024-01-21 |title=Anthropologist Paul Barnes: 'The conservation of species depends almost exclusively on philanthropy and goodwill' |url=https://english.elpais.com/science-tech/2024-01-21/anthropologist-paul-barnes-the-conservation-of-species-depends-almost-exclusively-on-philanthropy-and-goodwill.html |access-date=2024-09-17 |website=EL PAÍS English |language=en-us}} Some EDGE species, such as [elephants](/source/elephants) and [panda](/source/panda)s, are well-known and already receive considerable conservation attention, but many others, such as the [vaquita](/source/vaquita) (the world's rarest [cetacean](/source/cetacean))[http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/vaquita.htm Gulf of California Harbor Porpoise/ Vaquita/ Cochito/ (Phocoena sinus)]. (2012). National Oceanographic and Atmospheric Administration Office of Protected Resources.{{Cite journal | last1 = Isaac | first1 = N. J. B. | last2 = Turvey | first2 = S. T. | last3 = Collen | first3 = B. | last4 = Waterman | first4 = C. | title = Mammals on the EDGE: conservation priorities based on threat and phylogeny | doi = 10.1371/journal.pone.0000296 | journal = PLOS ONE | volume = 2 | issue = 3 | pages = e296 | year = 2007 | pmid = 17375184| pmc =1808424 | bibcode = 2007PLoSO...2..296I | doi-access = free }} the [bumblebee bat](/source/bumblebee_bat) (arguably the world's smallest mammal) and the egg-laying [long-beaked echidnas](/source/Long-beaked_echidna), are highly threatened yet remain poorly understood, and are frequently overlooked by existing conservation frameworks. The [Zoological Society of London](/source/Zoological_Society_of_London) launched the EDGE of Existence Programme in 2007 to raise awareness and funds for the conservation of these species. As of 2024, the programme has awarded fellows funds to help conserve 157 different species in 47 countries. The programme lists key supporters as the Fondation Franklinia, On the EDGE, and [Darwin Initiative](/source/Darwin_Initiative). Donors include the [IUCN](/source/International_Union_for_Conservation_of_Nature), [US Fish and Wildlife Service](/source/United_States_Fish_and_Wildlife_Service), and numerous non-governmental organisations and foundations.{{Cite web |title=Supporters |url=https://www.edgeofexistence.org/thanks/ |access-date=2024-09-17 |website=EDGE of Existence |language=en-GB}} In 2024, researchers at the programme identified EDGE Zones that make up 0.7% of Earth's surface but are home to one-third of the world's four-legged EDGE species.{{Cite journal |last1=Pipins |first1=Sebastian |last2=Baillie |first2=Jonathan E. M. |last3=Bowmer |first3=Alex |last4=Pollock |first4=Laura J. |last5=Owen |first5=Nisha |last6=Gumbs |first6=Rikki |date=2024-09-03 |title=Advancing EDGE Zones to identify spatial conservation priorities of tetrapod evolutionary history |journal=Nature Communications |language=en |volume=15 |issue=1 |page=7672 |doi=10.1038/s41467-024-51992-5 |pmid=39237497 |issn=2041-1723|pmc=11377708 }} == Conserving EDGE species == The EDGE of Existence programme is centred on an interactive website that features information on the top EDGE species detailing their specific [conservation](/source/Conservation_biology) requirements. 70% of the mammals which have been chosen are receiving little or no conservation attention according to the inventors.{{cite journal | vauthors = Isaac NJ, Turvey ST, Collen B, Waterman C, Baillie JE | editor1-last = Reid | year = 2007 | editor1-first = Walt | title = Mammals on the EDGE: Conservation Priorities Based on Threat and Phylogeny | journal = PLOS ONE | volume = 2 | issue = 3 | pages = e296 | doi = 10.1371/journal.pone.0000296 | pmid = 17375184 | pmc = 1808424| bibcode = 2007PLoSO...2..296I | doi-access = free }} == EDGE Fellows == EDGE research and conservation is carried out by ZSL researchers, a network of partner organizations and local scientists. An important part of the EDGE programme is a fellowship scheme which provides funding and support to local scientists. EDGE Fellows participate in all phases of a research project. Each project is focused on delivering a conservation action plan. Once the action plan is completed, a meeting is held to make additions and corrections to the document. == Calculating EDGE Scores == ===ED=== [[File:Edge_tree.png|thumb|In this [phylogenetic tree](/source/phylogenetic_tree), species A has a higher ED score than either species B or C — it represents a branch rather than a twig on the tree of life. If species A were to go extinct, there would be no similar species left on the planet and a larger amount of unique evolutionary history would be lost forever.]] Some species are more distinct than others because they represent a larger amount of unique evolution. Species like the [aardvark](/source/aardvark) have few close relatives and have been evolving independently for many millions of years. Others like the domestic [dog](/source/dog) originated only recently and have many close relatives. Species uniqueness can be measured as an 'Evolutionary Distinctiveness' (ED) score, using a [phylogeny](/source/phylogeny), or evolutionary tree. ED scores are calculated relative to a [clade](/source/clade) of species descended from a common ancestor. The three clades for which the EDGE of Existence Programme has calculated scores are all [class](/source/class_(biology))es, namely [mammal](/source/mammal)s, [amphibian](/source/amphibian)s, and [coral](/source/coral)s. The phylogenetic tree has the [most recent common ancestor](/source/most_recent_common_ancestor) at the root, all the current species as the leaves, and intermediate nodes at each point of branching [divergence](/source/Genetic_divergence). The branches are divided into segments (between one node and another node, a leaf, or the root). Each segment is assigned an ED score defined as the timespan it covers (in millions of years) divided by the number of species at the end of the subtree it forms. The ED of a species is the sum of the ED of the segments connecting it to the root. Thus, a long branch which produces few species will have a high ED, as the corresponding species are relatively distinctive, with few close relatives. ED metrics are not exact, because of uncertainties in both the ordering of nodes and the length of segments. ===GE=== GE is a number corresponding to a species' [conservation status](/source/conservation_status) according to the [International Union for Conservation of Nature](/source/International_Union_for_Conservation_of_Nature) with more endangered species having a higher GE: {|class="wikitable" |- ! [Conservation status](/source/Conservation_status) || Code !! GE score |- | [Extinct](/source/Extinction) || EX || — |- | [Extinct in the wild](/source/Extinct_in_the_wild) || EW || — |- | [Critically endangered](/source/Critically_endangered_species) || CR || 4 |- | [Endangered](/source/Endangered_species) || EN || 3 |- | [Vulnerable](/source/Vulnerable_species) || VU || 2 |- | [Near threatened](/source/Near_threatened) || NT || 1 |- | [Least concern](/source/Least_concern) || LC || 0 |- | [Data deficient](/source/Data_deficient) || DD || — |- | [Not evaluated](/source/Not_evaluated) || NE || — |} ===EDGE=== The EDGE score of a species is derived from its scores for Evolutionary Distinctness (ED) and for Globally Endangered status (GE) as follows: :\text{EDGE} = \ln (1+\text{ED}) + \text{GE}\cdot \ln (2)= \ln[(1+\text{ED})\cdot 2^{\text{GE}}] This means that a doubling in ED affects the EDGE score almost as much as increasing the threat level by one (e.g. from 'vulnerable' to 'endangered'). EDGE scores are an estimate of the expected loss of evolutionary history per unit time. EDGE species are species which have an above average ED score and are [threatened](/source/threatened_species) with extinction (critically endangered, endangered or vulnerable). There are currently 564 EDGE mammal species (≈12% of the total). Potential EDGE species are those with high ED scores but whose conservation status is unclear ([data deficient](/source/data_deficient) or [not evaluated](/source/not_evaluated)). == EDGE lists and focal species == Focal species are typically selected from the priority EDGE species. However, they also prioritise species outside these rankings. Such species can also have a very high ED but fall outside the top 100 EDGE rankings. These species are conserved by 'EDGE Fellows', who collect data on these species and develop conservation action plans.{{Cite web|url=https://www.edgeofexistence.org/focal-species/|title=Focal Species|website=EDGE of Existence|language=en-GB|access-date=2019-12-12}} Fellows have previously collaborated with institutions like National Geographic and The Disney Conservation Fund.{{Cite web |title=Meet the 10 Species ZSL EDGE of Existence and National Geographic Are Working to Protect in Asia |url=https://news.nationalgeographic.org/meet-the-10-species-zsl-edge-of-existence-and-national-geographic-are-working-to-protect-in-asia/ |access-date=2024-09-17 |website=news.nationalgeographic.org |language=en}}{{Cite web |last=Bruce |date=2017-04-20 |title=The Disney Conservation Fund Names the Recipients of its 2016-2017 Grants |url=https://thewaltdisneycompany.com/disney-conservation-fund-names-recipients-2016-2017-grants/ |access-date=2024-09-17 |website=The Walt Disney Company |language=en-US}} Top 3 ranked species on the 2024 EDGE lists for [amphibians](/source/Amphibian), [birds](/source/Bird), [gymnosperms](/source/Gymnosperm), [mammals](/source/Mammal), [ray-finned fish](/source/Actinopterygii), [lepidosaurs](/source/Lepidosauria), [crocodylians](/source/Crocodilia), [testudines](/source/Turtle), and [sharks and rays](/source/Elasmobranchii):{{Cite web |title=EDGE Lists |url=https://www.edgeofexistence.org/download-edge-lists/ |access-date=2025-08-26 |website=EDGE of Existence |language=en-GB}} === Amphibians === # [Bale Mountains frog](/source/Ericabatrachus) # [Amani forest frog](/source/Parhoplophryne) # [Bale Mountains tree frog](/source/Bale_Mountains_tree_frog) === Birds === # [Giant ibis](/source/Giant_ibis) # [Kakapo](/source/K%C4%81k%C4%81p%C5%8D) # [New Caledonian owlet-nightjar](/source/New_Caledonian_owlet-nightjar) === Gymnosperms === # [Maidenhair tree](/source/Ginkgo_biloba) # [Wollemi pine](/source/Wollemia) # [Parana pine](/source/Araucaria_angustifolia) === Mammals === # [Mountain pygmy possum](/source/Mountain_pygmy_possum) # [Aye-aye](/source/Aye-aye) # [Leadbeater's possum](/source/Leadbeater's_possum) === Ray-finned fish === # [Salamanderfish](/source/Lepidogalaxias) # ''[Typhleotris pauliani](/source/Typhleotris_pauliani)'' # [Barrow cave gudgeon](/source/Milyeringa_justitia) === Lepidosaur === # [Madagascar blindsnake](/source/Xenotyphlops_grandidieri) # [Chinese crocodile lizard](/source/Chinese_crocodile_lizard) # [Borneo earless monitor](/source/Earless_monitor_lizard) === Crocodylians === # [Gharial](/source/Gharial) # [Chinese alligator](/source/Chinese_alligator) # [False gharial](/source/False_gharial) === Testudines === # [Madagascar big-headed turtle](/source/Madagascan_big-headed_turtle) # [Western swamp turtle](/source/Western_swamp_turtle) # [Big-headed turtle](/source/Big-headed_turtle) === Sharks and rays === # [Narrow sawfish](/source/Knifetooth_sawfish) # [Bowmouth guitarfish](/source/Rhina_ancylostoma) # [Largetooth sawfish](/source/Largetooth_sawfish) The only current species with an EDGE median score over 100 are the maidenhair tree and wollemi pine. Examples of Critically Endangered species with very low EDGE median scores, 1 or below due to low evolutionary distinctness, are the [Algerian fir](/source/Abies_numidica), [Visayan warty pig](/source/Visayan_warty_pig), and [pindu](/source/pindu). The number of EDGE species varies by taxonomic group. For example, 8 crocodylians are EDGE species, representing more than 30% of crocdylians. Meanwhile 908 amphibians are EDGE species, representing less than 15% of amphibians.{{Cite web |title=EDGE Lists |url=https://www.edgeofexistence.org/edge-list/ |access-date=2024-09-17 |website=EDGE of Existence |language=en-GB}} == References == {{Reflist}} == External links == *[http://www.edgeofexistence.org EDGE of Existence website] *[http://www.zsl.org ZSL−Zoological Society of London website] {{ZSL}} . Category:Endangered species Category:Environmental research Category:Zoological Society of London --- Adapted from the Wikipedia article [EDGE of Existence programme](https://en.wikipedia.org/wiki/EDGE_of_Existence_programme) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/EDGE_of_Existence_programme?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.