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"Endemic" redirects here. Endemism_sentence_0

For the epidemiological context, see Endemic (epidemiology). Endemism_sentence_1

Endemism is the state of a species being native to a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. Endemism_sentence_2

For example, the Cape sugarbird is exclusively found in southwestern South Africa. Endemism_sentence_3

The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. Endemism_sentence_4

A rare alternative term for a species that is endemic is 'precinctive', which applies to species (and other taxonomic levels) that are restricted to a defined geographical area. Endemism_sentence_5

Etymology Endemism_section_0

The word endemic is from New Latin endēmicus, from Greek ενδήμος, endēmos, "native". Endemism_sentence_6

Endēmos is formed of en meaning "in", and dēmos meaning "the people". Endemism_sentence_7

The word entered the English language as a loan word from French endémique, and originally seems to have been used in the sense of diseases which occur at a constant amount in a country, as opposed to epidemic diseases, which are exploding in cases. Endemism_sentence_8

The word was used in biology in 1872 to mean a species restricted to a specific location by Charles Darwin. Endemism_sentence_9

The more uncommon term 'precinctive' has been used by a some entomologists as the equivalent of 'endemism'. Endemism_sentence_10

Precinctive was coined in 1900 by David Sharp when describing the Hawaiian insects, as he was uncomfortable with the usage of the word 'endemic' in a medical sense. Endemism_sentence_11

The word was first used in botany by Vaughan MacCaughey in Hawaii in 1917. Endemism_sentence_12

Overview Endemism_section_1

Endemism in general excludes examples kept by humans in botanical gardens or zoological parks, as well as populations introduced outside of their native ranges. Endemism_sentence_13

Juan J. Morrone states that a species may be endemic to any particular geographic region, regardless of size, thus the cougar is endemic to the Americas, however, endemism is normally used only where there is a considerable restriction in the area of distribution. Endemism_sentence_14

All species are not endemics, some species may be cosmopolitan. Endemism_sentence_15

All endemics are not necessarily rare -some might be common where they occur. Endemism_sentence_16

All rare species are not necessarily endemics, some may have a large range but be rare throughout this range. Endemism_sentence_17

Endemism is caused by historical and ecological factors. Endemism_sentence_18

Vicariant events caused by drifting continents, dispersal and extinction are some possible historical factors. Endemism_sentence_19

Ecological factors can explain the present limits on a distribution. Endemism_sentence_20

Endemic species are especially likely to develop on geographically and biologically isolated areas such as islands and remote island groups, including Hawaii, the Galápagos Islands and Socotra, because of the potential for isolation and therefore evolution through allopatric speciation. Endemism_sentence_21

Darwin's finches in the Galápagos archipelago are examples of species endemic to islands. Endemism_sentence_22

Similarly, isolated mountainous regions like the Ethiopian Highlands, or large bodies of water far from other lakes, like Lake Baikal, can also have high rates of endemism. Endemism_sentence_23

The stability of a region's climate and habitat through time may also contribute to high rates of endemism (especially paleoendemism), acting as refuges for species during times of climate change like Ice Ages. Endemism_sentence_24

These changes may have caused species to repeatedly restrict their ranges into these refuges, leading to regions with many small-ranged species. Endemism_sentence_25

In many cases biological factors, such as low rates of dispersal or returning to the spawning area (philopatry), can cause a particular group of organisms to have high speciation rates and thus many endemic species. Endemism_sentence_26

for example, cichlids in the East African Rift Lakes have diversified into many more endemic species than the other fish families in the same lakes, possibly due to such factors. Endemism_sentence_27

Plants which become endemic on isolated islands are often those which have a high rate of dispersal, and are able to reach such islands by being dispersed by birds. Endemism_sentence_28

Microorganisms were traditionally not believed to form endemics. Endemism_sentence_29

The hypothesis 'everything is everywhere', first stated in Dutch by Lourens G.M. Endemism_sentence_30

Baas Becking in 1934, describes the theory that the distribution of organisms smaller than 2mm is cosmopolitan where habitats occur that support their growth. Endemism_sentence_31

Subtypes Endemism_section_2

The first subcategories were first introduced by Claude P. E. Favager and Juliette Contandriopoulis in 1961: schizoendemics, apoendemics and patroendemics. Endemism_sentence_32

Using this work, Ledyard Stebbins and Jack Major then introduced the concepts of neoendemics and paleoendemics in 1965 to describe the endemics of California. Endemism_sentence_33

Endemic taxa can also be classified into autochtonous, allochtonous, taxonomic relicts and biogeographic relicts. Endemism_sentence_34

Paleoendemism refers to species that were formerly widespread but are now restricted to a smaller area. Endemism_sentence_35

Neoendemism refers to species that have recently arisen, such as through divergence and reproductive isolation or through hybridization and polyploidy in plants, and have not dispersed beyond a limited range. Endemism_sentence_36

Paleoendemism is more or less synonymous with the concept of a 'relict species': a population or taxon of organisms that was more widespread or more diverse in the past. Endemism_sentence_37

A 'relictual population' is a population that currently occurs in a restricted area, but whose original range was far wider during a previous geologic epoch. Endemism_sentence_38

Similarly, a 'relictual taxon' is a taxon (e.g. species or other lineage) that is the sole surviving representative of a formerly diverse group. Endemism_sentence_39

Schizoendemics, apoendemics and patroendemics can all be classified as types of neoendemics. Endemism_sentence_40

Schizoendemics arise from a wider distributed taxon which has become reproductively isolated without becoming (potentially) genetically isolated - a schizoendemic has the same chromosome count as the parent taxon it evolved from. Endemism_sentence_41

An apoendemic is a polyploid of the parent taxon (or taxa in the case of allopolyploids), whereas a patroendemic has a lower, diploid chromosome count than the related, more widely distributed polyploid taxon. Endemism_sentence_42

Mikio Ono coined the term 'aneuendemics' in 1991 for species which have more or less chromosomes than their relatives due to aneuploidy. Endemism_sentence_43

Pseudoendemics are taxa which have possibly recently evolved from a mutation. Endemism_sentence_44

Holoendemics is a concept introduced by Richardson 1978 to describe taxa which have remained endemic to a restricted distribution for a very long time. Endemism_sentence_45

In a 2000 paper, Myers and de Grave further attempted to redefine the concept. Endemism_sentence_46

In their view, everything is endemic, even cosmopolitan species are endemic to earth, and earlier definitions restricting endemics to specific locations are wrong. Endemism_sentence_47

Thus the subdivisions neoendemics and paleoendemics are without merit regarding the study of distributions, because these concepts consider that an endemic has a distribution limited to one place. Endemism_sentence_48

Instead, they propose four different categories: holoendemics, euryendemics, stenoendemics and rhoendemics. Endemism_sentence_49

In their scheme cryptoendemics and euendemics are further subdivisions of rhoendemics. Endemism_sentence_50

In their view, a holoendemic is a cosmopolitan species. Endemism_sentence_51

Stenoendemics, also known as local endemics, have a reduced distribution and are synonymous with the word 'endemics' in the traditional sense, whereas euryendemics have a larger distribution -both these have distributions which are more or less continuous. Endemism_sentence_52

A rhoendemic has a disjunct distribution. Endemism_sentence_53

Where this disjunct distribution is caused by vicariance, in an euendemic the vicariance was geologic in nature, such as the movement of tectonic plates, but in a cryptoendemic the disjunct distribution was due to extinction of the intervening populations. Endemism_sentence_54

There is yet another possible situation which can cause a disjunct distribution, where a species is able to colonise new territories by crossing over areas of unsuitable habitat, such as plants colonising an island -this situation they dismiss as extremely rare and do not devise a name for. Endemism_sentence_55

Traditionally, none of Myers and de Grave's categories would be considered endemics except stenoendemics. Endemism_sentence_56

Soil Endemism_section_3

Serpentine soils act as 'edaphic islands' of low fertility and these soils lead to high rates of endemism. Endemism_sentence_57

These soils are found in the Balkan Peninsula, Turkey, Alps, Cuba, New Caledonia, the North American Appalachians, and a scattered distribution in California, Oregon, and Washington and elsewhere For example, Mayer and Soltis considered the widespread subspecies Steptanthus glandulosus subsp. Endemism_sentence_58 glandulosus which grows on normal soils, to be a paleoendemic, whereas closely related endemic forms of S. glandulosus occurring on serpentine soil patches are neoendemics which recently evolved from subsp. Endemism_sentence_59

glandulosus. Endemism_sentence_60

Islands Endemism_section_4

Isolated islands commonly develop a number of endemics. Endemism_sentence_61

Mountains Endemism_section_5

Mountains can be seen as 'sky islands': refugia of endemics because species that live in the cool climates of mountain peaks are geographically isolated. Endemism_sentence_62

For example, in the Alpes-Maritimes department of France, Saxifraga florulenta, is an endemic plant that may have evolved in the Late Miocene and could have once been widespread across the Mediterranean Basin. Endemism_sentence_63

Conservation Endemism_section_6

Endemics might more easily become endangered or extinct because they are already restricted in distribution. Endemism_sentence_64

Some scientists claim that the presence of endemic species in an area is a good method to find geographical regions which can be considered priorities for conservation. Endemism_sentence_65

Endemism can thus be studied as a proxy for measuring biodiversity of a region. Endemism_sentence_66

The concept of finding endemic species which occur in the same region to designate 'endemism hotspots' was first proposed by Paul Müller in a 1973 book. Endemism_sentence_67

According to him, this is only possible where 1.) Endemism_sentence_68

the taxonomy of the species in question is not in dispute; 2.) Endemism_sentence_69

the species distribution is accurately known; and 3.) Endemism_sentence_70

the species have relatively small distributional ranges. Endemism_sentence_71

In a 2000 article, Myers et al. Endemism_sentence_72

used the standard of having more than 0.5% of the world's plant species being endemics of a the region to designate 25 geographical areas of the world as 'biodiversity hotspots'. Endemism_sentence_73

In response to the above, the World Wildlife fund has split the world into a few hundred geographical 'ecoregions'. Endemism_sentence_74

These have been designed to include as many species as possible which only occur in a single ecoregion, and these species are thus 'endemics' to these ecoregions. Endemism_sentence_75

Other scientists have argued that endemism is not an appropriate measure of biodiversity, because the levels of threat or biodiversity are not actually correlated to areas of high endemism. Endemism_sentence_76

When using bird species as an example, it was found that only 2.5% of biodiversity hotspots correlate with endemism and the threatened nature of a geographic region. Endemism_sentence_77

A similar pattern had been found before regarding mammals, Lasioglossum bees, Plusiinae moths, and swallowtail butterflies in North America: these different groups of taxa did not correlate geographically with each other regarding endemism and species richness. Endemism_sentence_78

Especially using mammals as flagship species proved to be a poor system of identifying and protecting areas of high invertebrate biodiversity. Endemism_sentence_79

In response to this, other scientists again defended the concept by using WWF ecoregions and reptiles, finding that most reptile endemics occur in WWF ecoregions with high biodiversity. Endemism_sentence_80

Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Endemism.