Dogs and Humans: Possibly a 32,000–Year-Old Friendship

“Man’s best friend” has had a close relationship with humans for thousands of years, which has resulted in the amazing diversity of breeds we’re familiar with today (specifically, more than 400 breeds exist today, 163 of which are recognized by the American Kennel Association). In fact, they’re the most diverse mammal species alive, with members that can have over a 100-fold weight difference. Previously, it was thought that dogs were domesticated from the gray wolf (Canis lupus) about 14,000 years ago. However, a recent genetic study in Science of prehistoric canids that lived in Eurasia and the Americas revealed that domestication may have actually occurred much longer ago, around 19,000 to 32,000 years ago.

Although genetic data had not previously supported these older domestication dates, there were suspicions that domestication happened earlier than 14,000 years ago since some of the oldest dog-like fossils are over 30,000 years old. These older dates are also interesting in that they place domestication as happening before widespread use of agriculture. Many humans were expanding their territories around 14,000 years ago, developing agriculture, and creating settlements. Permanent dwellings generated food waste that was hypothesized to have attracted local wolves. However, a domestication event of 19,000 to 32,000 years ago implies that it was primarily hunter-gathered societies (and not people using agriculture) that domesticated the first dogs.

Additionally, the new Science study also suggests that modern domesticated dogs are primarily European in origin, and may even have evolved from a canid species that is now extinct. However, the paper did not look at the genetics of East Asian prehistoric canids, so it cannot be ruled out that dogs may have been domesticated from other origins. Indeed, it’s been shown that one of the most famous doglike skulls, a 36,000-year-old skull from Belgian, was not an ancestor to our modern dogs, but a similar lineage that went extinct.

This most recent genetic study helps to serve as a reminder of what a special relationship we have with dogs, and to be sure to take care of our “best friend,” who’s been by our side for so many thousands of years. Three to four million dogs and cats are euthanized every year in the U.S. by shelters, according to the Humane Society of the United States. Only through proper planning and spaying and neutering can this ancient relationship be properly honored.

For much more on the domestication of the modern dog (and many other animals), see Teisha J. Rowland’s book Biology Bytes: Digestible Essays on Animals Both Commonplace and Bizarre.

For further reading:

• Teisha J. Rowland’s book Biology Bytes: Digestible Essays on Animals Both Commonplace and Bizarre
• O. Thalmann et al.’s article “Complete Mitochondrial Genomes of Ancient Canids Suggest a European Origin of Domestic Dogs” in Science
• Ed Young’s article “Dogs Adapted to Agriculture”
• Ed Young’s article “Origin of Domestic Dogs”