Scientists have discovered ancient wolf remains on a remote Swedish island in the Baltic Sea, suggesting humans transported them there thousands of years ago. The wolves, dated between 3,000 and 5,000 years old, shared a marine diet with local seal hunters and showed signs of human care. This finding challenges traditional views of early human-wolf interactions.
Researchers from the Francis Crick Institute, Stockholm University, the University of Aberdeen, and the University of East Anglia have unearthed evidence of grey wolves on Stora Karlsö, a tiny 2.5-square-kilometer island off Sweden's coast. The remains, found in Stora Förvar cave, date to the Neolithic and Bronze Ages, when the site served as a hub for seal hunters and fishers. With no native land mammals on the island, the wolves must have been brought by boat, indicating deliberate human action.
DNA analysis of two canid bones confirmed these were true wolves, lacking any dog ancestry. Isotope studies revealed their diet included seals and fish, mirroring that of the island's human inhabitants and implying they were fed by people. The wolves were smaller than mainland counterparts and exhibited low genetic diversity, traits associated with isolation or human management.
One Bronze Age wolf bone showed severe limb damage that would have impaired hunting, yet the animal survived, hinting at possible care from humans. "The discovery of these wolves on a remote island is completely unexpected," said Dr. Linus Girdland-Flink of the University of Aberdeen. "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."
Pontus Skoglund of the Francis Crick Institute added, "It was a complete surprise to see that it was a wolf and not a dog. This is a provocative case that raises the possibility that in certain environments, humans were able to keep wolves in their settlements, and found value in doing so."
Anders Bergström from the University of East Anglia noted the genetic intrigue: "The wolf with the most complete genome had low genetic diversity, lower than any other ancient wolf we've seen. This is similar to what you see in isolated or bottlenecked populations, or in domesticated organisms."
The study, published in Proceedings of the National Academy of Sciences, suggests prehistoric human-wolf bonds were more varied than previously thought, involving cooperation and management that predated full dog domestication. Jan Storå of Stockholm University emphasized, "The combination of data has revealed new and very unexpected perspectives on Stone Age and Bronze Age human-animal interactions in general and specifically concerning wolves and also dogs."
These insights, blending genetics and archaeology, highlight early experiments in animal husbandry on isolated frontiers.