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Allen's rule
Allen's rule A corollary to Bergmann's rule and Gloger's rule, holding that a race of warm-blooded species in a cold climate typically has shorter protruding body parts (nose, ears, tail, and legs) relative to body size than another race of the same species in a warm climate. This is because long protruding parts emit more body heat, and so are disadvantageous in a cool environment but advantageous in a warm environment. The idea is disputed, critics pointing to many other adaptations for heat conservation which are probably more important, notably fat layers, feathers, fur, and behavioural adaptations to avoid extreme temperatures. The rule was proposed by the American zoologist J. A. Allen in 1876.
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Cite this article
MICHAEL ALLABY. "Allen's rule." A Dictionary of Ecology. 2004. Encyclopedia.com. 31 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Allen's rule." A Dictionary of Ecology. 2004. Encyclopedia.com. (May 31, 2012). http://www.encyclopedia.com/doc/1O14-Allensrule.html MICHAEL ALLABY. "Allen's rule." A Dictionary of Ecology. 2004. Retrieved May 31, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O14-Allensrule.html |
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Allen's rule
Allen's rule A corollary to Bergmann's rule and Gloger's rule, holding that a race of warm-blooded species in a cold climate typically has shorter protruding body parts (nose, ears, tail, and legs) relative to body size than another race of the same species in a warm climate. This is because long protruding parts emit more body heat, and so are disadvantageous in a cool environment, but advantageous in a warm environment. The idea is disputed, critics pointing to many other adaptations for heat conservation which probably are more important, notably fat layers, feathers, fur, and behavioural adaptations to avoid extreme temperatures.
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Cite this article
AILSA ALLABY and MICHAEL ALLABY. "Allen's rule." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 31 May. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "Allen's rule." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (May 31, 2012). http://www.encyclopedia.com/doc/1O13-Allensrule.html AILSA ALLABY and MICHAEL ALLABY. "Allen's rule." A Dictionary of Earth Sciences. 1999. Retrieved May 31, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-Allensrule.html |
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Allen's rule
Allen's rule A corollary to Bergmann's rule and Gloger's rule, holding that a race of warm-blooded species in a cold climate typically has shorter protruding body parts (nose, ears, tail, and legs) relative to body size than another race of the same species in a warm climate. This is because long protruding parts emit more body heat, and so are disadvantageous in a cool environment, but advantageous in a warm environment. The idea is disputed, critics pointing to many other adaptations for heat conservation which probably are more important, notably fat layers, feathers, fur, and behavioural adaptations to avoid extreme temperatures.
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Cite this article
MICHAEL ALLABY. "Allen's rule." A Dictionary of Zoology. 1999. Encyclopedia.com. 31 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Allen's rule." A Dictionary of Zoology. 1999. Encyclopedia.com. (May 31, 2012). http://www.encyclopedia.com/doc/1O8-Allensrule.html MICHAEL ALLABY. "Allen's rule." A Dictionary of Zoology. 1999. Retrieved May 31, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-Allensrule.html |
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