Gigantothermy: Difference between revisions
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| ⚫ | {{Thermoreg}}'''Gigantothermy''' (sometimes called '''ectothermic homeothermy or inertial homeothermy''') is a phenomenon with significance in [[biology]] and [[paleontology]], whereby large, bulky [[ectotherm]]ic animals are more easily able to maintain a constant, relatively high [[body temperature]] than smaller animals by virtue of their smaller [[Volume-to-surface area ratio|surface area to volume ratio]].<ref>{{cite web |url=http://www.lib.ncsu.edu/resolver/1840.16/1335 |title=Thermoregulatory adaptations of Acrocanthosaurus atokensis - evidence from oxygen isotopes (Thesis) |last=Missell |first=Christine Ann |year=2004 |publisher=[[North Carolina State University]]}}</ref> A bigger animal has proportionately less of its body close to the outside environment than a smaller animal of otherwise similar shape, and so it gains heat from, or loses heat to, the environment much more slowly.<ref>{{cite web|url=http://www.bio.davidson.edu/people/midorcas/animalphysiology/websites/2005/Fitzpatrick/Gigantothermy.htm |title=Gigantothermy |year=2005 |first=Katie |last=Fitzpatrick |publisher=[[Davidson College]] |accessdate=2011-12-21}}</ref> |
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{{Thermoreg}} |
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| ⚫ | '''Gigantothermy''' (sometimes called '''ectothermic homeothermy''') is a phenomenon with significance in [[biology]] and [[paleontology]], whereby large, bulky [[ectotherm]]ic animals are more easily able to maintain a constant, relatively high [[body temperature]] than smaller animals by virtue of their smaller [[Volume-to-surface area ratio|surface area to volume ratio]].<ref>{{cite web |url=http://www.lib.ncsu.edu/resolver/1840.16/1335 |title=Thermoregulatory adaptations of Acrocanthosaurus atokensis - evidence from oxygen isotopes (Thesis) |last=Missell |first=Christine Ann |year=2004 |publisher=[[North Carolina State University]]}}</ref> A bigger animal has proportionately less of its body close to the outside environment than a smaller animal of otherwise similar shape, and so it gains heat from, or loses heat to, the environment much more slowly.<ref>{{cite web|url=http://www.bio.davidson.edu/people/midorcas/animalphysiology/websites/2005/Fitzpatrick/Gigantothermy.htm |title=Gigantothermy |year=2005 |first=Katie |last=Fitzpatrick |publisher=[[Davidson College]] |accessdate=2011-12-21}}</ref> |
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The phenomenon is important in the biology of ectothermic [[megafauna]], such as large [[turtle]]s, and aquatic reptiles like [[ichthyosaur]]s and [[mosasaur]]s{{Citation needed|date=August 2014}}. Gigantotherms, though almost always ectothermic, generally have a body temperature similar to that of [[endotherm]]s.{{Citation needed|date=July 2010}} It has been suggested that the larger [[dinosaurs]] would have been gigantothermic, rendering them virtually [[Homeotherm|homeothermic]].<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/science/nature/5166518.stm |title=Big dinosaurs 'had warmer blood' |work=[[BBC News]] |date=2006-07-11 |accessdate=2011-12-21}}</ref> |
The phenomenon is important in the biology of ectothermic [[megafauna]], such as large [[turtle]]s, and aquatic reptiles like [[ichthyosaur]]s and [[mosasaur]]s{{Citation needed|date=August 2014}}. Gigantotherms, though almost always ectothermic, generally have a body temperature similar to that of [[endotherm]]s.{{Citation needed|date=July 2010}} It has been suggested that the larger [[dinosaurs]] would have been gigantothermic, rendering them virtually [[Homeotherm|homeothermic]].<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/science/nature/5166518.stm |title=Big dinosaurs 'had warmer blood' |work=[[BBC News]] |date=2006-07-11 |accessdate=2011-12-21}}</ref> |
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== Negative Effects == |
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Gigantothermy allows animals to maintain body temperature, but is most likely detrimental to endurance and muscle power as compared with endotherms due to decreased anaerobic efficiency.<ref>{{Cite journal|title = Maximal Aerobic and Anaerobic Power Generation in Large Crocodiles versus Mammals: Implications for Dinosaur Gigantothermy|url = http://dx.doi.org/10.1371/journal.pone.0069361|journal = PLoS ONE|date = 2013-07-05|pmc = 3702618|pmid = 23861968|pages = e69361|volume = 8|issue = 7|doi = 10.1371/journal.pone.0069361|first = Roger S.|last = Seymour}}</ref> Mammals' bodies have roughly four times as much surface area occupied by mitochondria as reptiles. Increased mitochondria, necessitating larger energy demands, and consequently producing more heat to thermoregulate. An ectotherm the same size of an endotherm would not be able to remain as active as the endotherm, as heat is modulated behaviorally rather than biochemically. More time is dedicated to basking than eating. A large ectotherm, like a crocodile or alligator feeds by ambushing its prey whereas large mammals usually hunt. |
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==See also== |
==See also== |
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Revision as of 19:54, 7 December 2015
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Gigantothermy (sometimes called ectothermic homeothermy or inertial homeothermy) is a phenomenon with significance in biology and paleontology, whereby large, bulky ectothermic animals are more easily able to maintain a constant, relatively high body temperature than smaller animals by virtue of their smaller surface area to volume ratio.[1] A bigger animal has proportionately less of its body close to the outside environment than a smaller animal of otherwise similar shape, and so it gains heat from, or loses heat to, the environment much more slowly.[2]
The phenomenon is important in the biology of ectothermic megafauna, such as large turtles, and aquatic reptiles like ichthyosaurs and mosasaurs[citation needed]. Gigantotherms, though almost always ectothermic, generally have a body temperature similar to that of endotherms.[citation needed] It has been suggested that the larger dinosaurs would have been gigantothermic, rendering them virtually homeothermic.[3]
Negative Effects
Gigantothermy allows animals to maintain body temperature, but is most likely detrimental to endurance and muscle power as compared with endotherms due to decreased anaerobic efficiency.[4] Mammals' bodies have roughly four times as much surface area occupied by mitochondria as reptiles. Increased mitochondria, necessitating larger energy demands, and consequently producing more heat to thermoregulate. An ectotherm the same size of an endotherm would not be able to remain as active as the endotherm, as heat is modulated behaviorally rather than biochemically. More time is dedicated to basking than eating. A large ectotherm, like a crocodile or alligator feeds by ambushing its prey whereas large mammals usually hunt.
See also
References
- ^ Missell, Christine Ann (2004). "Thermoregulatory adaptations of Acrocanthosaurus atokensis - evidence from oxygen isotopes (Thesis)". North Carolina State University.
- ^ Fitzpatrick, Katie (2005). "Gigantothermy". Davidson College. Retrieved 2011-12-21.
- ^ "Big dinosaurs 'had warmer blood'". BBC News. 2006-07-11. Retrieved 2011-12-21.
- ^ Seymour, Roger S. (2013-07-05). "Maximal Aerobic and Anaerobic Power Generation in Large Crocodiles versus Mammals: Implications for Dinosaur Gigantothermy". PLoS ONE. 8 (7): e69361. doi:10.1371/journal.pone.0069361. PMC 3702618. PMID 23861968.
{{cite journal}}: CS1 maint: unflagged free DOI (link)
External links
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