Allen's rule

English

Etymology

Formulated by Joel Asaph Allen in 1877.

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.