Eurytherm

Thermoregulation in animals

A eurytherm is an organism, often an endotherm, that can function at a wide range of ambient temperatures.[1] To be considered a eurytherm, all stages of an organism's life cycle must be considered, including juvenile and larval stages.[2] These wide ranges of tolerable temperatures are directly derived from the tolerance of a given eurythermal organism's proteins.[3] Extreme examples of eurytherms include Tardigrades (Tardigrada), the desert pupfish (Cyprinodon macularis), and green crabs (Carcinus maenas), however, nearly all mammals, including humans, are considered eurytherms.[4][5][6] Eurythermy can be an evolutionary advantage: adaptations to cold temperatures, called cold-eurythemy, are seen as essential for the survival of species during ice ages.[7] In addition, the ability to survive in a wide range of temperatures increases a species' ability to inhabit other areas, an advantage for natural selection.

Eurythermy is an aspect of thermoregulation in organisms. It is in contrast with the idea of stenothermic organisms, which can only operate within a relatively narrow range of ambient temperatures.[8] Through a wide variety of thermal coping mechanisms, eurythermic organisms can either provide or expel heat for themselves in order to survive in cold or hot, respectively, or otherwise prepare themselves for extreme temperatures. Certain species of eurytherm have been shown to have unique protein synthesis processes that differentiate them from relatively stenothermic, but otherwise similar, species.

Picture of Canon Miles, Yukon, Canada
A boreal forest in Canada. This forest would likely house deciduous conifers.
  1. ^ Giomi, Folco; Pörtner, Hans-Otto (15 May 2013). "A role for haemolymph oxygen capacity in heat tolerance of eurythermal crabs". Frontiers in Physiology. 4: 110. doi:10.3389/fphys.2013.00110. PMC 3654213. PMID 23720633.
  2. ^ Dybern, Bernt I. (1965). "The Life Cycle of Ciona intestinalis (L.) f. typica in Relation to the Environmental Temperature". Oikos. 16 (1/2): 109–131. doi:10.2307/3564870. JSTOR 3564870.
  3. ^ Johnston, Ian A.; Bennett, Albert F., eds. (1996). Animals and temperature: phenotypic and evolutionary adaptation. Cambridge [England]: Cambridge University Press. p. 54. ISBN 978-0-521-49658-2. OCLC 34472042.
  4. ^ Lowe, Charles H.; Heath, Wallace G. (1969). "Behavioral and Physiological Responses to Temperature in the Desert Pupfish Cyprinodon macularius". Physiological Zoology. 42 (1): 53–59. doi:10.1086/physzool.42.1.30152465. ISSN 0031-935X. S2CID 86942420.
  5. ^ Horikawa, Daiki D. (2011-08-23), "Survival of Tardigrades in Extreme Environments: A Model Animal for Astrobiology", Anoxia, Cellular Origin, Life in Extreme Habitats and Astrobiology, vol. 21, Springer Netherlands, pp. 205–217, doi:10.1007/978-94-007-1896-8_12, ISBN 978-94-007-1895-1
  6. ^ Le Roux, P. J.; Branch, G. M.; Joska, M. A. P. (1990). "On the distribution, diet and possible impact of the invasive European shore crab Carcinus maenas (L.) along the South African coast". South African Journal of Marine Science. 9: 85–93. doi:10.2989/025776190784378835.
  7. ^ Portner, Hans O. (2004). "Climate Variability and the Energetic Pathways of Evolution: The Origin of Endothermy in Mammals and Birds" (PDF). Physiological and Biochemical Zoology. 77 (6): 959–981. doi:10.1086/423742. JSTOR 10.1086/423742. PMID 15674770. S2CID 15194087.
  8. ^ Hill R, Wyse G, Anderson A. Animal Physiology. 2004. Sinaur Associates, Inc.