A surprising discovery on a small island in the Baltic Sea is changing the way scientists think about the relationship between ancient humans and wolves.
Researchers have identified wolf remains approximately 3,000 to 5,000 years old on the Swedish island of Stora Karlsö. The discovery is notable because the island is isolated and has no native land mammals. Wolves could not have reached the island on their own, leading researchers to conclude that people must have transported them there.
The study, published in Proceedings of the National Academy of SciencesIt was conducted by scientists from the Francis Crick Institute, Stockholm University, the University of Aberdeen and the University of East Anglia. Their findings suggest that prehistoric communities may have managed or kept wolves in ways that have rarely been considered before.
Wolves on an island they couldn’t reach alone
These remains were found in the Stora Forvar Cave, an archaeological site on Stora Karlsø, which was heavily used by seal hunters and fishermen during the Neolithic and Bronze Age. These periods span thousands of years before modern civilization, spanning parts of the Stone Age and the early Metal Age.
Stora Karlsø covers only 2.5 square kilometers and lacks native terrestrial mammals. Since wolves are not naturally able to inhabit such an island across the open ocean, researchers believe that humans may have brought the animals there by boat.
That conclusion is what makes the discovery unusual. But further analysis revealed a more interesting story.
Evidence of life alongside humans
Scientists examined the remains of two canids, a group that includes wolves, dogs, foxes and related animals. Genetic testing confirmed that both specimens were wolves rather than dogs, and researchers found no evidence of dog ancestry.
Despite being genetically wolf-like, the animals displayed many characteristics that are often closely associated with people.
An important clue came from isotope analysis, a technique that can tell what an animal ate during its lifetime. The results showed that wolves consumed large amounts of marine proteins, including seal and fish. This closely matches the diet of the people living on the island, suggesting that the wolves were likely being fed by humans.
The wolves were smaller than the normal wolves living on the mainland. Furthermore, one animal showed unusually low genetic diversity. Genetic diversity refers to the range of genetic variation within an individual or population. Low diversity is often seen in isolated groups or in animals that have been selectively bred.
“The discovery of these wolves on a remote island is completely unexpected,” said the study’s lead author, Dr. Linus Gardland-Flink of the University of Aberdeen. “Not only did they have ancestry indistinguishable from other Eurasian wolves, but they lived alongside humans, ate their own food, and in a place they could only reach by boat. This paints a complex picture of the relationship between humans and wolves in the past.”
Rethinking the path to domestication
These findings challenge traditional ideas about how humans and wolves interacted in prehistory.
Scientists have long viewed the relationship between people and wolves largely through the lens of the domestication of dogs. In that framework, wolves gradually evolved into dogs through a long process of living with humans and adapting to human environments.
The newly discovered wolves don’t fit neatly into that story.
Researchers have not yet determined whether the animals were tamed, kept in captivity, or managed in some other way. However, their presence on an island inhabited by people strongly suggests an intentional and ongoing relationship.
“It was very surprising to see that it was a wolf, not a dog,” said senior author Pontus Skoglund of the Ancient Genomics Laboratory at the Francis Crick Institute. “This is an exciting case that raises the possibility that in some environments, humans were able to keep wolves in their settlements, and found value in doing so.”
Genetic clues point to human influence
Additional evidence came from genetic data.
Anders Bergström of the University of East Anglia and co-lead author pointed out that one of the wolves had exceptionally low genetic diversity, even compared to other ancient wolf specimens.
“The genetic data is fascinating. We found that the wolf with the most complete genome had low genetic diversity, which is lower than any other ancient wolf we’ve looked at. This is similar to what you see in isolated or bottlenecked populations or domesticated animals. While we can’t rule out that these wolves had low genetic diversity for natural reasons, it does suggest that humans were interacting with and managing wolves in ways we haven’t previously considered.” Was.”
Population bottleneck occurs when a group becomes too small, reducing genetic variation. Such patterns may emerge naturally, but they may also result from human management or selective breeding.
A wolf that may have been looked after
One of the most interesting discoveries involved a Bronze Age wolf suffering from severe damage to a limb bone.
The injury may have limited the animal’s ability to move and hunt effectively. Yet the wolf lived so long that its condition left visible marks on its skeleton.
Researchers suggest that this may indicate that the animal received some level of care or that it lived in conditions where it did not need to hunt large prey to survive.
New insights into ancient human-animal relationships
The study combined osteology, the study of bones, with advanced genetic analysis. Together, these approaches provided insights that neither method could reveal on its own.
“The combination of data has revealed new and very unexpected perspectives on Stone Age and Bronze Age human-animal interactions in general, and wolves and dogs in particular,” says Jan Stora, professor of osteoarchaeology at Stockholm University.
Overall, the research shows that relationships between humans and wolves were far more diverse than scientists had realized. Rather than simply hunting or avoiding wolves, some prehistoric communities may have formed long-term relationships with the animals, managing and caring for them without fully domesticating them.
The discovery points to a forgotten chapter in the history of humans and wolves, hinting at experiments in coexistence that ultimately never produced the dogs we know today.