Many domesticated animals have curly tails, floppy ears, mottled coats and child-like faces. A 60-year-long experiment on Siberian foxes helps explain why.

The African elephant has the biggest ears of any living animal. These floppy appendages serve to quickly dissipate heat through the ears’ many blood vessels into the air.

The consideration of ear position, he added, was an informal internal decision “that is more about adapting to people’s perceptions about floppy-eared dogs (sporting breeds) being more ...