Word.ws English Dictionary

Allen's rule

Allen's rule proper noun: an ecogeographic principle broadly stating that animals adapted to cold climates have relatively short limbs. Specifically, homeothermic animals in hot climates have low volume-to-surface ratios, and homeothermic animals in cold climates have high volume-to-surface ratios, due to thermal adaptation.

Proper noun

Allen's rule

  1. An ecogeographic principle broadly stating that animals adapted to cold climates have relatively short limbs. Specifically, homeothermic animals in hot climates have low volume-to-surface ratios, and homeothermic animals in cold climates have high volume-to-surface ratios, due to thermal adaptation.

Origin of Allen's rule

Formulated by Joel Asaph Allen in 1877.

Questions about Allen's rule

What does Allen's rule mean?
Allen's rule means an ecogeographic principle broadly stating that animals adapted to cold climates have relatively short limbs. Specifically, homeothermic animals in hot climates have low volume-to-surface ratios, and homeothermic animals in cold climates have high volume-to-surface ratios, due to thermal adaptation.
What part of speech is Allen's rule?
Allen's rule is a proper noun.

Words near Allen's rule in the dictionary

  1. Allen wrenches
  2. Allen's hare
  3. Allen's hares
  4. Allen's hummingbird
  5. Allen's hummingbirds
  6. Allen's rule
  7. Allen's swamp monkey
  8. Allen's swamp monkeys
  9. allenarly
  10. Allenbaugh
  11. Allenbaughs

Source and license

Adapted from Wiktionary: Allen's rule (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated:

Cite this entry: “Allen's rule.” Word.ws, https://word.ws/allen%27s_rule. Based on Wiktionary, CC BY-SA 4.0.