FACTOID # 9: The bookmobile capital of America is Kentucky.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Bergmann's rule
The large size of a polar bear allows it to radiate less heat in a cold climate.
The large size of a polar bear allows it to radiate less heat in a cold climate.
Some information on this page may be inconsistent; see the talk page for discussion.

In zoology, Bergmann's Rule is a principle that correlates environmental temperature with body mass in warm-blooded animals. It asserts that within a species, the body mass increases with latitude and colder climate. Among mammals and birds, individuals of a particular species in colder areas tend to have greater body mass than individuals in warmer areas. For instance, White-tailed Deer are larger in Canada than in the Florida Keys. The rule is named after a nineteenth-century German biologist, Christian Bergmann. Bergmann's rule and Allen's rule are examples of clines frequently seen in mammals. For the information on its source, see de:Eisbär, or [1]Miya 08:06, 19 Oct 2004 (UTC) Alternative image: zh-min-nan:Image:Peh-him (Ursus maritinus). ... For the information on its source, see de:Eisbär, or [1]Miya 08:06, 19 Oct 2004 (UTC) Alternative image: zh-min-nan:Image:Peh-him (Ursus maritinus). ... Binomial name Ursus maritimus Phipps, 1774 The polar bear (Ursus maritimus), also known as the white bear, northern bear, or sea bear, is a large bear native to the Arctic. ... Zoology is the biological discipline which involves the study of animals. ... A warm-blooded (homeothermic) animal is one that can keep its core body temperature at a nearly constant level regardless of the temperature of the surrounding environment (that is, to maintain thermal homeostasis) . This can involve not only the ability to generate heat, but also the ability to cool down... Latitude, usually denoted symbolically by the Greek letter φ, gives the location of a place on Earth north or south of the Equator. ... Orders Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Australosphenida Ausktribosphenida Monotremata Subclass Eutheria (excludes extinct ancestors) Afrosoricida Anagaloidea (extinct) Arctostylopida (extinct) Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Dinocerata (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Litopterna (extinct) Macroscelidea Mesonychia... Orders Many - see section below. ... Binomial name Odocoileus virginianus Zimmermann, 1780 The White-tailed deer (Odocoileus virginianus), also known as the Virginia deer, is a medium-sized deer found throughout most of the continental United States, southern Canada, Mexico, Central America and northern portions of South America as far south as Peru. ... Palm trees in Islamorada The Florida Keys are an archipelago, a string of about 1700 islands in the southeast United States. ... Karl Georg Lucas Christian Bergmann (18 May 1814–30 April 1865) was a German anatomist, physiologist and biologist who developed the Bergmanns rule. ... Allens rule is a biological rule posited by Joel Asaph Allen in 1877. ... In population genetics, a cline is a gradual change of a character or feature (phenotype) in a species over a geographical area, often as a result of environmental heterogeneity. ... Orders Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Australosphenida Ausktribosphenida Monotremata Subclass Eutheria (excludes extinct ancestors) Afrosoricida Anagaloidea (extinct) Arctostylopida (extinct) Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Dinocerata (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Litopterna (extinct) Macroscelidea Mesonychia...


This rule operates as larger animals have a lower surface area to volume ratio than smaller animals, so they radiate less body heat, and stay warmer in cold climates. On the other hand, warmer climates impose the opposite problem: body heat generated by metabolism needs to be dissipated quickly rather than stored within. Thus, the higher surface area-to-weight ratio in hot and dry climates facilitates heat loss through the skin and helps cooling of the body.


However, some notable exceptions of species with large mass and small surface-to-volume ratios that reside in warm climates exist, such as the African elephant. In this case, similar thermoregulatory optimizations may be operating, such as mass homeothermy to resist a significant rise in core body temperature in warm climates. Anecdotally, elephants are more frequently found in the shelter of shade when they are accompanied by calves, which have a significantly higher surface-to-volume ratio, and are much more prone to changes in temperature from radiant sources in the environment. (For similar arguments with references, see [1]).


For humans, the rule is true to a certain extent, but differing cultural practices including local diet and gene flow between populations must obviously account for much of this. For example, northern Asians are on average larger than their Southeast Asian counterparts. The Inuit of Alaska and northern Canada are known for their accumulation of fat and compact bodies as acclimatizations to severe cold. On the other hand, Southern Europeans, such as Italians, tend to be shorter on average than Northern Europeans, such as Swedes, which contradicts Bergmann's rule (taller frames yield a higher surface area-to-mass ratio, which would be expected to occur with greater frequency in warmer climates according to Bergmann's rule). Moreover, short, compact Pygmies are found only in tropical rainforests, so the importance of heat dissipation alone cannot explain the smaller stature; the hot, humid rainforest environment would seem to encourage taller, leaner frames, but other selective pressures must override those corresponding to Bergmann's rule. Human beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. ... For other uses, see Inuit (disambiguation). ... Generally speaking, pygmy (from Greek pygmaios, fist sized, a kind of dwarf in Greek mythology) can refer to any human or animal of unusually small size, for example, the pygmy hippopotamus. ...

[edit]

See also

[edit]

Allens rule is a biological rule posited by Joel Asaph Allen in 1877. ... Glogers Rule is a zoological rule which states that within the same species of endotherms, more heavily pigmented forms tend to be found near the equator and lighter forms away from the equator. ...

References

  • Carl Bergmann. "Über die Verhältnisse der wärmeökonomie der Thiere zu ihrer Grösse." Göttinger Studien, Göttingen, 1847, 3 (1), 595-708.
  • Roberts DF (1953) Body weight, race and climate. Am. J. Phys. Anthropol. 11:533–558.
  • Roberts DF (1978) Climate and Human Variability. 2nd ed. Menlo Park, CA: Cummings
  • Ruff CB (1994) Morphological adaptation to climate in modern and fossil hominids. Yrbk. Phys. Anthropol. 37:65--107
  • Schreider E (1950) Geographical distribution of the body-weight/body-surface ratio. Nature 165:286
 This ecology-related article is a stub. You can help Wikipedia by expanding it.

  Results from FactBites:
 
Landlaw Specialty Publishers (4287 words)
The Bergmanns' right to use the common driveway for access and the installation and maintenance of underground utilities for their home is governed by a Common Driveway and Utility Easement agreement dated October 12, 1990 and a Limited Utility Easement and Restriction agreement dated November 24, 1992.
I find and rule that the Bergmanns' trimming and planting in Area 3 was within their rights under the easement agreement (although the Ritters may remove and/or change those plantings at any time they wish), and that the electrical transformer was located and installed with Ms.
Bergmann admitted at trial that he knew at that time where the lot line was, and knew from the building permit that their house was as close to that line as it could be.
Bergmann's Rule at AllExperts (622 words)
In zoology, Bergmann's Rule is a principle that correlates environmental temperature with body mass in warm-blooded animals.
Bergmann's rule and Allen's rule are examples of clines frequently seen in mammals.
For humans, the rule is true to a certain extent, but differing cultural practices including local diet and gene flow between populations must obviously account for much of this.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m