One scientist bred tame foxes from wild ones in under a decade, selecting one trait

Starting in 1959, Soviet geneticist Dmitry Belyaev bred silver foxes selecting only for tameness around humans, nothing else. Within a few generations, the friendliest foxes started showing floppy ears, curly tails and piebald coats, traits never selected for directly, mirroring the exact differences between wolves and dogs. The experiment, still running today, offered strong evidence that domestication's whole suite of physical changes can cascade from selecting a single behavioural trait.

— Lee Alan Dugatkin and Lyudmila Trut, How to Tame a Fox (and Build a Dog) — University of Chicago Press, 2017
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