Wolf remains discovered on a tiny island in the Baltic Sea are forcing scientists to reconsider what they know about the early relationship between humans and wolves. The island has no native land mammals and no route by which wolves could have arrived without human help.
Researchers identified the remains on Stora Karlsö, a Swedish island covering just 2.5 square kilometers, according to a report from Science Daily. The remains date back roughly 3,000 to 5,000 years. Because wolves cannot cross open sea to colonize such an island on their own, researchers concluded that people must have transported them there, likely by boat.
The study was conducted by scientists from the Francis Crick Institute, Stockholm University, the University of Aberdeen, and the University of East Anglia. It was published in the Proceedings of the National Academy of Sciences.
The remains were found in Stora Förvar cave, an archaeological site on the island that was heavily used by seal hunters and fishers during the Neolithic and Bronze Ages. Those periods span parts of the Stone Age and early metalworking eras, thousands of years before modern civilization.
Genetic testing confirmed that both specimens were wolves, not dogs. The researchers found no evidence of dog ancestry in either animal. That distinction matters, because it means whatever relationship these animals had with humans predates the fully domesticated dog.
Despite being genetically wolves, the animals showed several characteristics associated with living alongside people. Isotope analysis, a technique that reveals what an animal ate during its lifetime, showed that the wolves consumed large amounts of marine protein, including seals and fish. That diet closely matched what the people living on the island were eating, strongly suggesting that humans were feeding the animals.
The combination of evidence, an island they could not have reached alone, a human-matching diet, and physical traits associated with close contact with people, points toward a relationship that researchers say has rarely been considered in previous models of domestication. The findings suggest that prehistoric communities may have been managing or keeping wolves in ways that go well beyond what earlier theories proposed.
The discovery does not rewrite the timeline of dog domestication outright, but it adds a new layer of complexity. It raises the possibility that humans were actively caring for wolves, and possibly even selectively breeding them, long before the domesticated dog as a species emerged. Researchers say the find opens new questions about what early human-animal relationships actually looked like in practice.
