For more than 50 years, scientists have been gathering foxes from the Russian wilderness and breeding them, picking the most human-friendly to mate to domesticate the supposedly untamable animals, much as dogs once were, Phys.org reports. And it looks like the project the BBC says was started by Dmitry Belyae and his intern, Lyudmila Trut, has been a success: By the fourth generation of foxes, the animals were acting much like socialized dogs, wagging their tails and seeking human contact, and they'd physically changed, too, with droopier ears, shorter legs and snouts, and higher serotonin levels, which may have dampened aggressiveness. In the late 1950s Belyae and Trut set out to domesticate a species from the ground up—in a country that Live Science notes banned the study of genetics in 1948, with severe punishments for those who flouted the law.
In the beginning, the researchers pretended they were breeding foxes for their fur (and they did kill for fur those foxes that weren't docile enough to continue mating for their real experiment). What's interesting is that the foxes on the farm weren't "tamed," per se, which is learned behavior not passed down to the next generation, Popular Science explained in 2013. Rather, a 2009 paper by Trut (Belyae died in 1985, and Trut, now in her 80s, has been running the project since) notes that the meticulously selective breeding led to the neurological and endocrinal changes the foxes underwent, per Discover. Now that the foxes have been domesticated, Trut's next task is to isolate the genes that are altered during this process. Read the BBC story for a fascinating look at the experiment, which as of last month involved 340 foxes. (Our house cats, meanwhile, aren't too far-removed from their wild relatives.)