Image: Zefram, Wikimedia Commons

An unorthodox experiment with foxes proves that the selection of certain behavioral traits can lead to domesticated animals, in addition to creating biological changes.

Dmitry K. Belyaev was a Russian geneticist interested in studying the shared traits of domesticated animals. He initiated a remarkable project which began in the 1950s and still continues today. His mission was to domesticate the wild silver-black fox through behavioral selection.

Belyaev theorized that breeding generations of foxes based on their behavioral tendencies towards humans could essentially result in fully domesticated animals.

His operation involved mating selected foxes based on specific criteria. The experimental animals were tested beginning at one month of age through maturity, which is around seven to eight months. Researchers approached each fox’s cage and observed the fox’s reaction to their presence. They would then progress to touching if the animal responded favorably. The least aggressive foxes were bred to each other and the process was repeated in a controlled scientific fashion over forty generations. 

Image: Wikipedia

The end results were astonishing, revealing numbers of domesticated foxes that preferred to be around humans rather than other foxes and would exemplify excited whimpering, licking and wagging actions similar to dogs.

Perhaps the most interesting aspect of the experiment, however, was the obvious physical and physiological changes. The domesticated foxes had altered coat colors, floppy ears, shorter tails, weakened pheromones, and softer jaws and faces. They also displayed lower adrenaline levels and less fearful tendencies.

Belyaev’s experiment revolutionized the way scientists view domestication and its future applications to other wild species. 

Today, there are more than 300 domesticated foxes living that resulted from the study — perhaps the only truly tame foxes in the world.