Allen's Rule

Definition

A biological rule stating that animals with shorter limbs tend to be found in colder climates, while animals with longer limbs tend to be found in warmer climates.

Etymology

Named after the American zoologist and anthropologist, Joel Asaph Allen.

Example

Allen's rule explains why some arctic animals have shorter limbs than their relatives in warmer climates.

Related Terms

• Thermoregulation
• Limb length
• Climate adaptation