Scientists have uncovered ancient wolf remains on a small, isolated island in the Baltic Sea, suggesting that these animals were brought there by early humans. The study, published in the Proceedings of the National Academy of Sciences, was conducted by researchers from the Francis Crick Institute, Stockholm University, the University of Aberdeen, and the University of East Anglia. The findings propose that grey wolves may have been managed or controlled by prehistoric societies.
The discovery was made in the Stora Förvar cave on the Swedish island of Stora Karlsö, a site historically utilized by seal hunters and fishers during the Neolithic and Bronze Ages. This island, spanning only 2.5 square kilometers, hosts no native land mammals, implying that any such animals must have been introduced by humans. Genomic analysis of the remains confirmed they were wolves, not dogs, and exhibited no dog ancestry.
Unexpected Findings in Ancient Wolf Remains
Isotope analysis of the wolf bones revealed a diet rich in marine protein, such as seals and fish, aligning with the human diet on the island. This suggests the wolves were provisioned by humans. Furthermore, the wolves were smaller than typical mainland wolves, and one individual displayed signs of low genetic diversity, a common consequence of isolation or controlled breeding.
“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.”
This finding challenges conventional understanding of wolf-human dynamics and the process of dog domestication. While it remains unclear if these wolves were tamed, kept in captivity, or managed in some other way, their presence in a human-occupied, isolated environment points to a deliberate and sustained interaction.
Implications for Understanding Human-Animal Relationships
The study raises intriguing questions about the nature of human-animal relationships in prehistory. Pontus Skoglund of the Ancient Genomics Laboratory at the Francis Crick Institute and senior author commented on the significance of the findings.
“It was a complete surprise to see that it was a wolf and not a dog,” said Skoglund. “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 of the University of East Anglia, another co-lead author, emphasized the genetic data’s importance. “We found that 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,” he noted. “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.”
Historical Context and Future Research Directions
One of the wolf specimens, dating back to the Bronze Age, exhibited advanced pathology in a limb bone, which would have limited its mobility. This suggests it may have been cared for or survived in an environment where it did not need to hunt large prey. The combination of osteology and genetic analyses has provided unique insights not available separately.
“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,” says Jan Storå, Professor of Osteoarchaeology at Stockholm University.
The study suggests that human-wolf interactions in prehistory were more diverse than previously thought, extending beyond simple hunting or avoidance to include complex relations and interactions. These interactions mirror new aspects of domestication without leading to the canines we recognize as dogs today. As researchers continue to explore these ancient relationships, further studies may reveal more about the intricate dynamics between early humans and the animal world.
