Not to be confused with Ecophenotype or Subspecies.

In evolutionary ecology, an ecotype,[note 1] sometimes called ecospecies, describes a genetically distinct geographic variety, population or race within a species, which is adapted to specific environmental conditions.

Typically, though ecotypes exhibit phenotypic differences (such as in morphology or physiology) stemming from environmental heterogeneity, they are capable of interbreeding with other geographically adjacent ecotypes without loss of fertility or vigor. [1][2][3][4][5]

Range and distribution

Experiments indicate that sometimes ecotypes manifest only when separated by great spatial distances (of the order of 1,000 km). This is due to hybridization whereby different but adjacent varieties of the same species (or generally of the same taxonomic rank) interbreed, thus overcoming local selection. However other studies reveal that the opposite may happen, i.e., ecotypes revealing at very small scales (of the order of 10 m), within populations, and despite hybridization.[1]

In ecotypes, it is common for continuous, gradual geographic variation to impose analogous phenotypic and/or genetic variation.[1] This situation is called cline. A well-known example of cline is the skin color gradation in indigenous human populations worldwide, which is related to latitude and amounts of sunlight.[6] But often the distribution of ecotypes is bimodal or multimodal. This means that ecotypes may display two or more distinct and discontinuous phenotypes even within the same population. Such phenomenon may lead to speciation and can occur if conditions in a local environment change dramatically through space or time.[1]


Rangifer tarandus caribou, a member of the woodland ecotype.


Ecotypes have no main taxonomic rank in modern biological classification. However some scientists consider them "taxonomically equivalent to subspecies". This is true in the sense that ecotypes can be sometimes classified as subspecies and the opposite.

Ecotypes are closely related to morphs. In the context of evolutionary biology, genetic polymorphism is the occurrence in equilibrium of two or more distinctly different phenotypes within a population of a species, in other words, the occurrence of more than one form or morph. The frequency of these discontinuous forms (even that of the rarest) is too high to be explained by mutation. In order to be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (whose all members can potentially interbreed). Polymorphism is actively and steadily maintained in populations of species by natural selection (most famously sexual dimorphism in humans) in contrast to transient polymorphisms where conditions in a habitat change in such a way that a "form" is being replaced completely by another.

In fact, Begon, Townsend and Harper assert that

There is not always clear distinction between local ecotypes and genetic polymorphisms.

The notions "form" and "ecotype" may appear to correspond to a static phenomenon, however this is not always the case. Evolution occurs continuously both in time and space, so that two ecotypes or forms may qualify as distinct species in only a few generations. Begon, Townsend and Harper use an illuminating analogy on this:

… the origin of a species, whether allopatric or sympatric, is a process, not an event. For the formation of a new species, like the boiling of an egg, there is some freedom to argue about when it is completed.

Thus ecotypes and morphs can be thought of as precursory steps of potential speciation.

See also


  1. Greek: οίκος = home and τύπος = type, coined by Göte Turesson in 1922
  2. Banfield, who worked with both the Canadian Wildlife Service and the National Museum of Canada, in his often-cited 1961 classification, identified five subspecies of Rangifer tarandus: 1) the largely migratory barren-ground caribou subspecies Rangifer tarandus groenlandicus, which are found mainly in the Canadian territories of Nunavut and the Northwest Territories, along with western Greenland; 2) the subspecies Rangifer tarandus caribou which is divided into ecotypes: boreal woodland caribou, (also known as forest-dwelling, woodland caribou (boreal), mountain woodland caribou and migratory woodland caribou) —the migratory George River Caribou Herd, for example in the Ungava region of Quebec; 3) Rangifer tarandus pearyi (Peary caribou), the smallest of the species, known as Tuktu in Inuktitut, found in the northern islands of Nunavut and the Northwest Territories; 4) Rangifer tarandus granti subspecies Grant’s caribou, which are mainly migratory and live in Alaska and the northern Yukon and 5) the R. t. dawsoni subspecies; † Queen Charlotte Islands caribou from the Queen Charlotte Islands (extinct since 1910)


  1. 1 2 3 4 5 Ecology: From individuals to ecosystems by Begon, Townsend, Harper, Blackwell Publishing 4th ed. (2006), p.5,6,7,8
  2. Turesson, Turesson G. (1922). The genotypical response of the plant species to the habitat. Hereditas 3. pp. 211–350.
  3. Molles, Manuel C., Jr. (2005). Ecology: Concepts and Applications (3rd ed.). New York: The McGraw-Hill Companies, Inc. p. 201. ISBN 0-07-243969-6.
  4. Environmental Encyclopedia by Bortman, Brimblecombe, Mary Ann Cunningham, William P. Cunningham, Freedman - 3rd ed., p.435, "Ecotype"
  6. "Race". (2009). Encyclopædia Britannica. Ultimate Reference Suite. Chicago: Encyclopædia Britannica.
  7. Earthworm ecotypes, information from the Earthworm Society of Britain about the different ecotypes of British earthworms.
  8. "reindeer (Rangifer tarandus)" Encyclopædia Britannica. Ultimate Reference Suite. Chicago: Encyclopædia Britannica, 2009
  9. 1 2 "Designatable Units for Caribou (Rangifer tarandus) in Canada" (PDF), COSEWIC, Ottawa, Ontario: Committee on the Status of Endangered Wildlife in Canada, p. 88, 2011, retrieved 18 December 2013
  10. COSEWIC 2011:3.
  11. Banfield, Alexander William Francis (1961), "A Revision of the Reindeer and Caribou, Genus Rangifer", Bulletin, Biological Services, National Museum of Canada, 177 (66)
  12. Reindeer
  13. Bergerud, Arthur T. (1996), "Evolving Perspectives on Caribou Population Dynamics, Have We Got it Right Yet?", Rangifer, Special Issue (9): 59–115
  14. Festa-Bianchet, M.; Ray, J.C.; Boutin, S.; Côté, S.D.; Gunn, A.; et al. (2011), "Conservation of Caribou (Rangifer tarandus) in Canada: An Uncertain Future", Canadian Journal of Zoology, 89: 419–434, doi:10.1139/z11-025
  15. Mager, Karen H. (2012), Population Structure and Hybridization of Alaskan Caribou and Reindeer: Integrating Genetics and Local Knowledge (PDF) (PhD dissertation), Fairbanks, Alaska: e University of Alaska Fairbanks, retrieved 27 December 2013
  16. "Riverine and marine ecotypes of Sotalia dolphins are different species".
  17. Common bottlenose dolphin
  18. Encyclopedia of life sciences, 2007, John Wiley & Sons, "Darwin's Finches"
  19. Introduction to Ecology (1983), J.C. Emberlin, chapter 8
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