allen's rule

Science Dictionary
Allen's rule   (āl'ənz)  Pronunciation Key 
The principle holding that in a warm-blooded animal species having distinct geographic populations, the limbs, ears, and other appendages of the animals living in cold climates tend to be shorter than in animals of the same species living in warm climates. Shorter and more compact body parts have less surface area than elongated ones and thus radiate less body heat. Allen's rule is named for the American zoologist Joel Allen (1838-1921). Compare Bergmann's rule.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Explore Dictionary.com
Previous Definition: allelopathy
Next Definition: allergen
Words Near: allen's rule
More from Thesaurus.com
Synonyms and Antonyms for allen's rule
More from Reference.com
Search for articles containing allen's rule
More from Dictionary.com Translator
Dictionary.com Word FAQs

Dictionary.com presents 366 FAQs, incorporating some of the frequently asked questions from the past with newer queries.

Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature