Endemism

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The orange-breasted sunbird (Nectarinia violacea) is exclusively found in South African fynbos vegetation. Orange-breasted Sunbird (Nectarinia violacea).jpg
The orange-breasted sunbird (Nectarinia violacea) is exclusively found in South African fynbos vegetation.
Bicolored frog (Clinotarsus curtipes) is endemic to the Western Ghats of India Bicolored Frog ( Clinotarsus curtipes ).jpg
Bicolored frog (Clinotarsus curtipes) is endemic to the Western Ghats of India

Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, nation, country or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species that is endemic is precinctive, which applies to species (and subspecific categories) that are restricted to a defined geographical area.

In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined.

In biogeography, a species is indigenous to a given region or ecosystem if its presence in that region is the result of only natural processes, with no human intervention. The term is equivalent to the concept of native or autochthonous species. Every wild organism has its own natural range of distribution in which it is regarded as indigenous. Outside this native range, a species may be introduced by human activity, either intentionally or unintentionally; it is then referred to as an introduced species within the regions where it was anthropogenically introduced.

Cosmopolitan distribution Biogeographic term

In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. Such a taxon is said to exhibit cosmopolitanism or cosmopolitism. The opposite extreme is endemism.

Contents

Etymology

The word endemic is from New Latin endēmicus, from Greek ενδήμος, endēmos, "native". Endēmos is formed of en meaning "in", and dēmos meaning "the people". [1] The term "precinctive" has been suggested by some scientists as the equivalent of "endemism", [lower-alpha 1] and was first used in botany by MacCaughey in 1917. [2] Precinction was perhaps first used by Frank and McCoy. [3] [4] Precinctive seems to have been coined by David Sharp when describing the Hawaiian fauna in 1900: [5] "I use the word precinctive in the sense of 'confined to the area under discussion' ... 'precinctive forms' means those forms that are confined to the area specified." That definition excludes artificial confinement of examples by humans in far-off botanical gardens or zoological parks.

New Latin Form of the Latin language between c. 1375 and c. 1900

New Latin was a revival in the use of Latin in original, scholarly, and scientific works between c. 1375 and c. 1900. Modern scholarly and technical nomenclature, such as in zoological and botanical taxonomy and international scientific vocabulary, draws extensively from New Latin vocabulary. In such use, New Latin is subject to new word formation. As a language for full expression in prose or poetry, however, it is often distinguished from its successor, Contemporary Latin.

Greek language Language spoken in Greece, Cyprus and Southern Albania

Greek is an independent branch of the Indo-European family of languages, native to Greece, Cyprus and other parts of the Eastern Mediterranean and the Black Sea. It has the longest documented history of any living Indo-European language, spanning at least 3500 years of written records. Its writing system has been the Greek alphabet for the major part of its history; other systems, such as Linear B and the Cypriot syllabary, were used previously. The alphabet arose from the Phoenician script and was in turn the basis of the Latin, Cyrillic, Armenian, Coptic, Gothic, and many other writing systems.

Overview

Chorus cicada, a species endemic to New Zealand Chorus cicada.jpg
Chorus cicada, a species endemic to New Zealand

Physical, climatic, and biological factors can contribute to endemism. The orange-breasted sunbird is exclusively found in the fynbos vegetation zone of southwestern South Africa. The glacier bear is found only in limited places in Southeast Alaska. Political factors can play a part if a species is protected, or actively hunted, in one jurisdiction but not another.[ citation needed ]

Orange-breasted sunbird species of bird

The orange-breasted sunbird is the only member of the bird genus Anthobaphes; however, it is sometimes placed in the genus Nectarinia. This sunbird is endemic to the fynbos habitat of southwestern South Africa. They are sexually dimorphic with females being olive green while the males are orange to yellow on the underside with bright green, blue and purple on the head and neck.

Fynbos Shrubland and heathland ecoregion of southwestern South Africa

Fynbos is a small belt of natural shrubland or heathland vegetation located in the Western Cape and Eastern Cape provinces of South Africa. This area is predominantly winter rainfall coastal and mountainous areas with a Mediterranean climate. The fynbos ecoregion is within the Mediterranean forests, woodlands, and scrub biome. In fields related to biogeography, fynbos is known for its exceptional degree of biodiversity and endemism, consisting about 80% species of the Cape floral kingdom where nearly 6,000 of them are endemic. This land has faced severe threats and still does, but due to the many economic uses conservation efforts are being made to help restore it.

South Africa Republic in the southernmost part of Africa

South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by 2,798 kilometres (1,739 mi) of coastline of Southern Africa stretching along the South Atlantic and Indian Oceans; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; and to the east and northeast by Mozambique and Eswatini (Swaziland); and it surrounds the enclaved country of Lesotho. South Africa is the largest country in Southern Africa and the 24th-largest country in the world by land area and, with over 58 million people, is also the world's 24th-most populous nation. It is the southernmost country on the mainland of the Old World or the Eastern Hemisphere. About 80 percent of South Africans are of Bantu ancestry, divided among a variety of ethnic groups speaking different African languages, nine of which have official status. The remaining population consists of Africa's largest communities of European, Asian (Indian), and multiracial (Coloured) ancestry.

There are two subcategories of endemism: paleoendemism and neoendemism. Paleoendemism refers to species that were formerly widespread but are now restricted to a smaller area. Neoendemism refers to species that have recently arisen, such as through divergence and reproductive isolation or through hybridization and polyploidy in plants.

Paleoendemism along with neoendemism is one of two sub-categories of endemism. Paleoendemism refers to species that were formerly widespread but are now restricted to a smaller area. Neoendemism refers to species that have recently arisen, such as through divergence and reproductive isolation or through hybridization and polyploidy in plants.

Neoendemism is one of two sub-categories of endemism, the ecological state of a species being unique to a defined geographic location. Specifically, neoendemic species are those that have recently arisen, through divergence and reproductive isolation or through hybridization and polyploidy in plants. Paleoendemism, the other sub-category, refers to species that were formerly widespread but are now restricted to a smaller area.

Polyploidy Chromosomal constitution of a cell containing multiples of the normal number of chromosomes

Polyploidy is the state of a cell or organism having more than two paired (homologous) sets of chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two sets of chromosomes—one set inherited from each parent. However, some organisms are polyploid, and polyploidy is especially common in plants. In addition, polyploidy occurs in some tissues of animals that are otherwise diploid, such as human muscle tissues. This is known as endopolyploidy. Species whose cells do not have nuclei, that is, prokaryotes, may be polyploid, as seen in the large bacterium Epulopiscium fishelsoni. Hence ploidy is defined with respect to a cell. Most eukaryotes have diploid somatic cells, but produce haploid gametes by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis, the sporophyte generation is diploid and produces spores by meiosis.

Endemic types or species are especially likely to develop on geographically and biologically isolated areas such as islands and remote island groups, such as Hawaii, the Galápagos Islands, and Socotra; they can equally develop in biologically isolated areas such as the highlands of Ethiopia, or large bodies of water far from other lakes, like Lake Baikal. Hydrangea hirta is an example of an endemic species found in Japan.

Located about 2300 miles (3680 km) from the nearest continental shore, the Hawaiian Islands are the most isolated group of islands on the planet. The plant and animal life of the Hawaiian archipelago is the result of early, very infrequent colonizations of arriving species and the slow evolution of those species—in isolation from the rest of the world's flora and fauna—over a period of at least 5 million years. As a consequence, Hawai'i is home to a large number of endemic species. The radiation of species described by Charles Darwin in the Galapagos Islands which was critical to the formulation of his theory of evolution is far exceeded in the more isolated Hawaiian Islands.

Galápagos Islands Achipelago and protected area of Ecuador in the Pacific Ocean

The Galápagos Islands, part of the Republic of Ecuador, are an archipelago of volcanic islands distributed on either side of the equator in the Pacific Ocean surrounding the centre of the Western Hemisphere, 906 km (563 mi) west of continental Ecuador. The islands are known for their large number of endemic species and were studied by Charles Darwin during the second voyage of HMS Beagle. His observations and collections contributed to the inception of Darwin's theory of evolution by means of natural selection.

Socotra The largest of four islands of the Socotra archipelago, Yemen

Socotra, also called Soqotra, located between the Guardafui Channel and the Arabian Sea, is the largest of four islands in the Socotra archipelago. The territory is located near major shipping routes and is officially part of Yemen, and had long been a subdivision of the Aden Governorate. In 2004, it became attached to the Hadhramaut Governorate, which is much closer to the island than Aden. In 2013, the archipelago became its own governorate, the Socotra Governorate.

Endemics can easily become endangered or extinct if their restricted habitat changes, particularly—but not only—due to human actions, including the introduction of new organisms. There were millions of both Bermuda petrels and Bermuda cedars in Bermuda when it was settled at the start of the seventeenth century. By the end of the century, the petrels were thought extinct. Cedars, already ravaged by centuries of shipbuilding, were driven nearly to extinction in the twentieth century by the introduction of a parasite. Bermuda petrels and cedars are now rare, as are other species endemic to Bermuda.

Introduced species species introduced either deliberately or accidentally through human activity

An introduced species, alien species, exotic species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there by human activity, either deliberate or accidental. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are called invasive species. The process of human-caused introduction is distinguished from biological colonization, in which species spread to new areas through "natural" (non-human) means such as storms and rafting.

Bermuda petrel species of bird

The Bermuda petrel is a gadfly petrel. Commonly known in Bermuda as the cahow, a name derived from its eerie cries, this nocturnal ground-nesting seabird is the national bird of Bermuda and can be found on Bermudian money. It is the second rarest seabird on the planet and a symbol of hope for nature conservation. They are known for their medium-sized body and long wings. The Bermuda petrel has a greyish-black crown and collar, dark grey upper-wings and tail, white upper-tail coverts and white under-wings edged with black, and the underparts are completely white.

<i>Juniperus bermudiana</i> species of plant

Juniperus bermudiana is a species of juniper endemic to Bermuda. This species is most commonly known as Bermuda cedar, but is also referred to as Bermuda juniper. Historically, this tree formed woodland that covered much of Bermuda. Settlers cleared part of the forest and the tree was used for many purposes including building construction and was especially prized for shipbuilding. However scale insects introduced during World War II devastated the forests, killing over 99% of the Bermuda cedar. Since then, the salt tolerant casuarina has been planted as a replacement species, and a small number of Bermuda cedars have been found to be resistant to the scale insects. Populations of certain endemic birds which had co-evolved with the tree have plummeted as a result of its demise.

Threats to highly endemistic regions

Principal causes of habitat degradation and loss in highly endemistic ecosystems include agriculture, urban growth, surface mining, mineral extraction, logging operations, [6] [7] and slash-and-burn agriculture.

Notes

  1. Precinctivity

Related Research Articles

Black-capped petrel species of bird

The black-capped petrel is a small seabird in the gadfly petrel genus, Pterodroma. It is also known as the diablotín. It is a long-winged petrel with a grey-brown back and wings, with a white nape and rump. Underparts are mainly white apart from a black cap and some dark underwing markings. It picks food items such as squid from the ocean surface.

Ecotone transition area between two biomes

An ecotone is a transition area between two biomes. It is where two communities meet and integrate. It may be narrow or wide, and it may be local or regional. An ecotone may appear on the ground as a gradual blending of the two communities across a broad area, or it may manifest itself as a sharp boundary line.

A biodiversity hotspot is a biogeographic region with significant levels of biodiversity that is threatened by human habitation.

Wildlife of Bermuda

The flora and fauna of Bermuda form part of a unique ecosystem due to Bermuda's isolation from the mainland of North America. The wide range of endemic species and the islands form a distinct ecoregion, the Bermuda subtropical conifer forests.

An Endemic Bird Area (EBA) is an area of land identified by BirdLife International as being important for habitat-based bird conservation because it contains the habitats of restricted-range bird species, which are thereby endemic to them. An EBA is formed where the distributions of two or more such restricted-range species overlap. Using this guideline, 218 EBAs were identified when Birdlife International established their Biodiversity project in 1987. A secondary EBA comprises the range of only one restricted-range species.

Galápagos petrel species of bird

The Galápagos petrel is one of the six endemic seabirds of the Galápagos. Its scientific name derives from Ancient Greek: Pterodroma originates from pteron and dromos, meaning "wing" and "runner", and phaeopygia comes from phaios and pugios, meaning "dusky" and "rump". Members of Pterodroma genus are also called the gadfly petrels because their erratic twisting and turning in flight resemble that of gadflies.

Hawaiian petrel species of bird

The Hawaiian petrel or ʻuaʻu is a large, dark grey-brown and white petrel that is endemic to Hawaiʻi.

Calcareous glade

A calcareous glade is an ecological community that is found in the central eastern United States. Calcareous glades occur where bedrock such as limestone occurs near or at the surface, and have very shallow and little soil development. Because of the shallow soil and the extreme conditions created by it, trees are often unable to grow in the glades. This creates a habitat that is usually sunny, dry, and hot. Calcareous glade vegetation is more similar to that of a desert habitat than a grassland, being dominated by small spring annuals with occasional geophytic or succulent perennials.

Fauna of Puerto Rico Animals found in the United States Territory of Puerto Rico

The fauna of Puerto Rico is similar to other island archipelago faunas, with high endemism, and low, skewed taxonomic diversity. Bats are the only extant native terrestrial mammals in Puerto Rico. All other terrestrial mammals in the area were introduced by humans, and include species such as cats, goats, sheep, the small Asian mongoose, and escaped monkeys. Marine mammals include dolphins, manatees, and whales. Of the 349 bird species, about 120 breed in the archipelago, and 47.5% are accidental or rare.

Fauna of Ghana

The wildlife of Ghana is composed of its biodiversity of flora and fauna.

<i>Cassine laneana</i> species of plant

Cassine laneana, commonly known as the Bermuda olivewood, is a species of large tree in the staff vine family, Celastraceae, that is endemic to the islands of Bermuda. Although once found in the extensive subtropical coniferous forests that covered the islands, it is currently restricted to small protected areas, such as Spittal Pond. C. laneana can grow anywhere from 25 to 40 feet tall, with leaves that are 1 to 2.5 inches long and 0.5 to 1.5 inches wide. The leaves are also a deep green colour when they are older and a bright green colour when they are younger. C. laneana flowers in late spring and early summer and produces a small ovate berry that is an olive colour and 0.25 to 0.5 inches long.

Wildlife of Sri Lanka includes its flora and fauna and their natural habitats. Sri Lanka has one of the highest rates of biological endemism in the world.

An adventive species is a species that has arrived in a new locality. It may have had help from humans as an introduced species or it may not.

<i>Xylocopa sonorina</i> species of insect

Xylocopa sonorina, the Hawaiian Carpenter Bee, is a carpenter bee found in the eastern Pacific islands. Males are golden brown and lack stingers; females are black and larger than the males and considered shy. In tropical climates, females will lay eggs all year, with interruptions due to cold weather. After collecting pollen and preparing tunneled chambers out of wood, a single female will deposit eggs on pollen balls within the chamber and seal it. The eggs will hatch two to three days later, with larvae maturing in two weeks, and prepupal and pupal stages lasting 3–4 weeks. New adults will begin buzzing a week later and flying in two to three more weeks.

Short-range endemic (SRE) invertebrates are animals that display restricted geographic distributions, nominally less than 10,000 km2, that may also be disjunct and highly localised. The most appropriate analogy is that of an island, where the movement of fauna is restricted by the surrounding marine waters, therefore isolating the fauna from other terrestrial populations. Isolating mechanisms and features such as roads, urban infrastructure, large creek lines and ridges can act to prevent the dispersal and gene flow of the less mobile invertebrate species. Subterranean fauna, which include stygofauna and troglofauna, typically comprise short-range endemics.

In biogeography and paleontology a relict is a population or taxon of organisms that was more widespread or more diverse in the past. A relictual population is a population that presently occurs in a restricted area, but whose original range was far wider during a previous geologic epoch. Similarly, a relictual taxon is a taxon that is the sole surviving representative of a formerly diverse group.

References

  1. "Endemic". Reference.com. Retrieved 6 December 2014.
  2. MacCaughey, Vaughan (August 1917). "A survey of the Hawaiian land flora" (PDF). Botanical Gazette. LXIV (2): 92. doi:10.1086/332097.
  3. Frank, J. H.; McCoy, E. D. (March 1990). "Endemics and epidemics of shibboleths and other things causing chaos". Florida Entomologist. 73 (1): 1–9. JSTOR   3495327.
  4. Frank, J. H.; McCoy, E. D. (March 1995). "Precinctive insect species in Florida". Florida Entomologist. 78 (1): 21–35. JSTOR   3495663. [also uses word precinction]
  5. Sharp, D. 1900. Coleoptera. I. Coleoptera Phytophaga, pp. 91–116 in D. Sharp [ed.]. Fauna Hawaiiensis, Being the Land-Fauna of the Hawaiian Islands. Cambridge Univ. Press; Cambridge, vol. 2 part 3 [see p. 91].
  6. Smiet, Fred (June 1982). "Threats to the Spice Islands". Oryx. 16 (4): 323–328. doi:10.1017/S0030605300017774.
  7. Foley, Jonathan A.; et al. (February 2007). "Amazonia revealed: forest degradation and loss of ecosystem goods and services in the Amazon Basin". Frontiers in Ecology and the Environment. Ecological Society of America. 5 (1): 25–32. doi:10.1890/1540-9295(2007)5[25:ARFDAL]2.0.CO;2.

Further reading