Ask Smithsonian: When Did People Start Keeping Pets?

The human-pet timeline is still being put together, but turns out man’s best friend might also be his oldest

Pets have been harnessed to humans for possibly tens of thousands of years.

Regardless of when pet ownership got started, our long attachment to these animals is still going strong. Americans own some 78 million dogs, 85 million cats, 14 million birds, 12 million small mammals and 9 million reptiles, according to pet industry statistics.

The archaeological and genetic record is being combed and analyzed for evidence of when and how the human-animal bond developed, not just to satisfy a craving for trivia, but because it says a lot about the evolution of human society, says Greger Larson, director of the University of Oxford’s palaeogenomics and bio-archaeology research network, which is leading a major international project to determine the origins of dogs.

People who have pets have free time and wealth, he says. Pets are animals that are kept for pleasure, and they have been tamed and domesticated. A domestic animal has also been tamed, and is kept by humans as a food source, for work, or only for pleasure. Not all domestic animals are pets, though they can be—think of a chicken, pig, or a cow. And not all tame animals are domestic—an elephant or a tiger, for instance.

One thing is certain: “We know that dogs, without a doubt, were the first domestic animal,” says Larson, meaning that they were tamed and used for work or their fur or meat.  But it’s unclear if dogs were the first pets—that is, kept solely for their companionship—he says. So which animals were the first pet? “The answer to that question is, nobody really knows,” says Larson.

The story of domestication—and pets—is not a linear progression from wild to domestic, he says. It’s more about how animals have taken on different roles in human society over the centuries. “These things exist on a continuum,” says Larson. Asking when the first pet came into being is “a bit like asking when did life begin,” he says.

Humans have likely kept baby animals for amusement as long as humans have lived, says Larson. But, usually, as those babies matured and became less cute and perhaps more unruly, they ended up being thrown back into the wild or maybe even eaten.

One study published by University of Maine researchers in 2011 found evidence that dogs were being bred, and, eaten on occasion, by humans living in Texas some 9,400 years ago. The giveaway was a small dog bone found in ancient human fecal matter.

The bone fragment provided the oldest known record of dogs in the New World, although Dennis Stanford, archaeologist and director of the Paleo-Indian/Paleoecology Program at the Smithsonian’s National Museum of Natural History, and colleagues are analyzing dog bones found in Colorado that they believe may be some 11,000 years old.

Larson and his colleagues recently published evidence that dogs were domesticated twice—once in Europe about 16,000 years ago and then again in Asia some 14,000 years ago—from two separate wolf lineages.

But they may have been domesticated even earlier. A scientist who’s participating in Larson’s project—Mietje Germonpre, of the Royal Belgian Institute of Natural Sciences—has published data showing that a 32,000-year-old canine-like skull found in a cave in Belgium was possibly the first dog.

“What she has posed is an interesting hypothesis,” Larson says, noting that her data is being tested by the collaboration.

Larson’s network has collected almost 1,500 DNA samples from ancient dog and wolf remains, and will soon be interpreting the data, in an effort to solve the domestication mystery.

And it may also help scientists determine when dogs first became “man’s best friend.”

Some clues exist. Dogs and cats were buried with humans some 12,000 years ago, but it’s not clear why, says Larson. Dogs also got special burials, sometimes with high-value items in their graves, at least 8,000 years ago, but again, the reason for the special treatment is not known.

The Romans kept small toy dogs some 2,000 years ago. They did not appear to have any utility, but they also came into fashion around the same time that the black rat became a major pest in Europe, notes Larson.

And a few hundred years ago, he says, European royalty began making garments with special pockets to stash small dogs. They also traded dogs with each other, and often commissioned portraits of the animal in its new surroundings, said Larson. Around the same time, dogs were being bred for particular behaviors and aesthetics, which would be pretty hard evidence that dogs were indeed pets, not working animals, he says.

Larson, with his international project, is doggedly working on establishing a time frame from beast of burden to best friend.

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