It’s Been a Long Doggone Friendship
June 1, 2015
Genetic clues from a 35,000-year-old fossil provide evidence that the dog became our best friend thousands of years earlier than most archaeologists had previously thought. Until recently, scientists believed that dogs—as we know them today—and people had lived with each other for at least 14,000 years. That date made the dog the oldest known domesticated animal. However, this latest research pushes that date back even further. The findings suggest that dogs may have been first domesticated as long as 40,000 years ago.
Scientists know that modern domestic dogs are descended from wolves. Earlier genetic studies of wolves and ancient and modern dogs placed the dog’s domestication in Europe, China, or the Middle East. The oldest archaeological sites where human and dog remains occur together are dated from 11,000 to 12,000 years old. However, archaeologists now suspect that dogs may have been domesticated much earlier.
Geneticist Pontus Skoglund of the Harvard Medical School in Boston, Massachusetts, analyzed DNA obtained from the fossilized rib of a Siberian wolf discovered in 2010. The fossil was part of a collection recovered by a joint Swedish and Russian team on the Taymyr Peninsula in Russian Siberia in 2010. The frozen permafrost of this region preserves the remains of long-extinct prehistoric animals in such good condition that scientists can extract DNA from the fossilized bones.
Skoglund’s team compared the DNA they obtained from the 35,000-year-old rib bone of an ancient wolf, labeled Taimyr 1, to DNA sequences from ancient and living wolves and dogs. They found that the Taimyr 1 wolf belonged to a lineage that diverged from the ancestors of dogs and existing wolves at roughly the same time that dog and wolf lineages split from each other. From this, they used various techniques to calculate when the earliest dogs split from the ancestors of modern wolves. The results suggests that the two groups split some time between about 40,000 and 27,000 years ago.
Some dogs, including huskies, preserve DNA from a line of wolves that lived 35,000 years ago in the area that is now Siberia. (copyright melis/ShutterStock)
Some dogs today, including Siberian huskies and Greenland sled dogs, still preserve some DNA inherited from the wolf lineage that included Taimyr 1. The researchers involved believe that the first domestic dogs might have been hunting companions for people who settled Europe and Asia during the last Ice Age.
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