The domestication of animals (and plants) was born out of somewhat of a necessity for early hunter-gatherers. The process itself modifies a species genetically through selective breeding, ultimately allowing humans control over an animal’s behavior.
For years, accredited institutions have successfully housed, and even bred, hundreds of species of wild animals in captive settings. It’s important to discern, though, that the act of simply keeping these animals alive in captivity does not mean the species, as a whole, has been domesticated.
The process of domestication is not a simple one. In fact, of 148 large mammalian species, only 14 of them are domesticated. Biologist, author and professor Jared Diamond argues there are six restrictions wild animals need to fulfill in order for domestication to be attainable. Without even just one of these traits, the likelihood that domestication can occur lessens significantly.
The restrictions Diamond believes prohibit animals from becoming domesticated are: diet, growth rate, disposition, reluctance to breed in captivity, social hierarchies, and their tendency to panic or flee. Consider the horse, an animal that has been domesticated for at least 5,000 years. Now consider its close relative, the zebra. Despite various attempts, we’ve never been able to domesticate the zebra.
For most species, domestication is slow and tedious, but not always. In the 1950s, Russian scientist Dmitri Belyaev set up a long-term experiment to study the domestication of silver foxes. In the past 50 years he has managed to selectively breed silver foxes for tameness and against aggression.
The results of his experiment show a number of behavioral, morphological and physiological changes. In short, the animals at his facility have begun to undergo a number of the changes hypothesized by Charles Darwin to occur through domestication.
While it may certainly be possible to expedite the domestication process for viable candidates, domestication in this manner is simply not attainable for the vast majority of wild animals.