Archaeologists studying the Stora Förvar cave on the remote Swedish island of Stora Karlsö have discovered ancient wolf remains, suggesting that ancient humans may have partially domesticated and even hunted alongside wolves thousands of years after the first domesticated dogs appeared.
The international effort led by scientists from the University of Aberdeen, the University of East Anglia, and Stockholm University could rewrite the history of wolf domestication, human-wolf coexistence, and potential cross-species collaboration.
“It was a complete surprise to see that it was a wolf and not a dog,” explained the study’s lead author, Pontus Skoglund of the Ancient Genomics Laboratory at the Francis Crick Institute, about the unexpected find. Skoglund also described the discovery as a ‘provocative case’ which suggests that, under the right conditions and in certain environments, humans were able to keep wolves in their settlements, and found value in doing so.”
According to a statement announcing the discovery, Stora Karlsö island, which is only 2.5 square kilometers in size, was used extensively by Stone Age and Bronze Age seal hunters and fishers due to the access to seals and fish. However, the researchers also note, the tiny island has no native land animals. This suggests that any land animals were almost surely brought there by ancient humans.
During a series of recent excavations, the research team unearthed remains of two ancient canids inside Stora Förvar cave. After using conventional techniques to date the remains, 3,000 and 5,000 years old respectively, the archaeologists performed several tests to determine whether the remains were from wolves or dogs and whether they showed signs of domestication. Notably, the team said that the island cave, which had been previously explored between 1888 and 1893, has a limestone-rich bedrock that “contributed to the skeletal material found there being very well preserved.”
Surprisingly, the genetic analysis confirmed the animal remains were indeed wolves, and not dogs. The analysis also showed that the animals possessed “no evidence” of dog ancestry, meaning they had not been bred with previously domesticated animals. Notably, the genetic analysis of one of the canids “showed signs” of low genetic diversity. The team said this finding suggests “at least partial domestication” of wolves by ancient humans.
Anders Bergström of the University of East Anglia, and co-lead author of the study detailing the team’s research, called the genetic data “fascinating,” while noting that the wolf with the most complete genome had genetic diversity “lower than any other ancient wolf we’ve seen.” The researcher said this type of genetic profile is similar to those found in isolated or bottlenecked populations, “or in domesticated organisms.”
“While we can’t rule out that these wolves had low genetic diversity for natural reasons, it suggests that humans were interacting with and managing wolves in ways we hadn’t previously considered,” Bergström explained.
An isotope analysis of the animals’ bones found that both had a diet rich in marine protein, including seals and fish. The researchers said this finding aligns the animal’s diet with that of the ancient humans on the island, “suggesting they were provisioned.” The two canid remains were also smaller than typical mainland wolves, also suggesting at least partial domestication.
When performing a physical examination of the Bronze Age canid remains, the researchers found signs of an “advanced pathology” in one of its limb bones that would have limited the animal’s mobility. The team said the finding suggests the wolf may have been cared for or at least lived in an environment where it did not need to hunt larger prey.
When discussing the genetic and physical analysis, Jan Storå, Professor of Osteoarchaeology at Stockholm University, said the combination of data “has revealed new and very unexpected perspectives on Stone Age and Bronze Age human-animal interactions” in general, but also specifically “concerning wolves and also dogs.”
“The discovery of these wolves on a remote island is completely unexpected,” said Dr. Linus Girdland-Flink of the University of Aberdeen, a lead author of the study. “Not only did they have ancestry indistinguishable from other Eurasian wolves, but they seemed to be living alongside humans, eating their food, and in a place they could have only reached by boat.”
“This paints a complex picture of the relationship between humans and wolves in the past,” Dr. Girdland-Flink added.
The study “Gray wolves in an anthropogenic context on a small island in prehistoric Scandinavia” was published in the Proceedings of the National Academy of Sciences.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.