Archaeologists use salmon snacks to trace early dog-human friendship

Recent archaeological discoveries in Alaska suggest that the human bond with dogs in the Americas may have begun as early as 12,000 years ago, pushing the timeline of human-canine companionship back about 2,000 years earlier than previously recorded.

In 2018, archaeologists unearthed a tibia, or lower-leg bone, of an adult canine at an archaeological site in Alaska called Swan Point, approximately 70 miles southeast of Fairbanks, as reported by IFLScience. Radiocarbon dating revealed that the canine from Swan Point lived about 12,000 years ago, towards the end of the Ice Age, as noted by Popular Science.

Scientists from the University of Arizona based their research on this canine tibia found at Swan Point. Through chemical analyses, the team identified substantial contributions from salmon proteins in the bone, indicating that these ancient canids regularly fed on salmon—an unusual diet for canids of that era and region who typically hunted terrestrial animals, as reported by Science Focus.

Since it's unlikely the canines were hunting salmon from the region's rivers at this time, it suggests they had been dependent on humans for food. "This is the smoking gun because they're not really going after salmon in the wild," said Ben Potter, a study co-author and University of Alaska Fairbanks archaeologist.

"We now have evidence that canids and people had close relationships earlier than we knew they did in the Americas," said François Lanoë, lead study author and assistant research professor of anthropology at the University of Arizona.

"Behaviorally, they seem to be like dogs, as they ate salmon provided by people, but genetically, they're not related to anything we know," Lanoë explained, according to IFLScience.

Although the specimens acted and looked like dogs, genetically, they are a medley of different canid species, unlike anything that exists today, as noted by Science Focus. Previous genetic evidence has suggested that dogs rapidly dispersed across America beginning around 15,000 years ago. However, the physical remains of prehistoric canids are sparse in the Americas, as reported by IFLScience.

The team is confident that this is the earliest known relationship between humans and dogs, but it is too early to know for sure, according to Science Focus. Although it is premature to assert that these remains belong to the first domesticated dogs of the Americas, the discovery provides new information about the relationship between canids and humans in ancient times, as reported by Popular Science.

According to Lanoë, it is possible that these canids were actually domesticated wolves rather than true dogs, and it is also possible that they were tamed wolves instead of fully domesticated dogs.

"The terminal Pleistocene in interior Alaska may have been a time of experimentation in terms of human-canid relationships," Lanoë and his colleagues write. "People may have domesticated canids that left no trace in later dog lineages. Alternatively, some wild canids may have been kept as pets and others hunted."

The researchers identified 76 canids found across Alaska. They identified dogs (Canis familiaris), ancient wolves (Canis lupus), wolfdogs (Canis lupus/familiaris), and coyotes (Canis latrans).

"It asks the existential question, what is a dog?" said Potter. 

This article was written in collaboration with generative AI company Alchemiq