Allen's rule


Definition of Allen's rule

: a statement in zoology: protruding body parts (as ears, tail, legs, bill) of warm-blooded animals are relatively shorter in cooler than in warmer parts of the range

First Known Use of Allen's rule

1937, in the meaning defined above

History and Etymology for Allen's rule

after Joel A. Allen

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The first known use of Allen's rule was in 1937

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Allen's hummingbird

Allen's rule


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Cite this Entry

“Allen's rule.” Dictionary, Merriam-Webster, Accessed 30 Sep. 2022.

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