60 Years in the Making: The Domestication of the Siberian Silver Fox

Credit: Raffaele Esposito via Flickr
Credit: Raffaele Esposito via Flickr

For millennia, dogs have lived side-by-side with humans. It took thousands of years to domesticate them. Cats have lived amongst humans for more than 4,000 years, but are still only considered semi-domesticated. But, it only took 35 years to domesticate the silver fox in Siberia.  For the last 60 years, a team of Soviet geneticists have been running a unique biology experiment which gives us a real-time window into domestication in action. 

The Great Soviet Experiment

In 1959, the Soviet geneticist, Dmitry Belyaev, purchased 130 silver foxes from Soviet fur farms and began selecting them for friendliness toward humans. His goal was to study the process of domestication in real-time. He was especially keen on understanding how dogs had evolved from wolves. He chose silver foxes instead of wolves, and kept only the most tame foxes - approximately 20% of the population - for to breed the next generation. 

Domestication in Action

After several generations, the foxes traits and appearance had already changed. Their ears were floppy, they were smaller, their tails became curly, they had an extended reproductive cycle, and the shape of their skulls, jaws, and teeth changed. These traits can also be found in other domesticated species, and are now thought to be inherently linked to the process of domestication. Belyaev’s findings supported Darwin’s hypothesis in the Origin of Species, where he wrote that “not a single domestic animal can be named which has not, in some country, drooping ears.” 

When the foxes reached sexual maturity, they were given an overall tameness score. Those that were least fearful and were not aggressive towards humans were allowed to breed. “To ensure that tameness resulted from genetic selection and not simply from experience with humans, the foxes were not trained and were only allowed short ‘time dosage’ contact with their caretakers.” 

Credit: Sputnik/Science Photo Library via Wikimedia Commons
Credit: Sputnik/Science Photo Library via Wikimedia Commons

60 Years Later

After breeding more than 40 generations of the species, the result is a group of “friendly, domesticated foxes which were more eager to hang out with humans, whimpered to attract attention, and sniffed and licked their caretakers. They wagged their tails when they were happy or excited.” They are no longer fearful of humans or new stimuli, and are curious when it comes to exploring new situations. In recent years, their genome has been mapped, and the results indicate that there is a potential genetic link to tameness.

Still today, research continues. The domestication experiment was almost halted after the fall of the USSR when funding dried up. The number of foxes dropped from 700 to just 100 a decade later, as scientists were forced to sell the foxes for fur to continue their research. Today, you can support their research by buying one of these domesticated foxes as a pet, for the tidy sum of $9,000. If you’re after something a little more affordable, why not check out one of our animal posters below. 

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