When people first set foot into the Americas, they were closely followed by a set of fluffy paws. This is according to new research that suggests some of the first people to settle in the Americas likely brought their dogs along with them.
It’s thought that dogs split from wolf ancestors between 27,000 and 40,000 years ago, and these dogs became domesticated in Eurasia between 18,000 and 30,000 years ago, but much of this story remains a mystery. The story of how humans settled in the Americas is even more controversial and filled with doubt, although most experts currently agree that people crossed from Siberia to North America sometime before 15,000 years ago.
This new research suggests that dogs were domesticated in Siberia 23,000 years ago. Dogs then rapidly dispersed across America beginning around 15,000 years ago, around the same time as humans did, indicating that people brought a number of dogs with them during some of their earlier migrations from Siberia.
"We have long known that the first Americans must have possessed well-honed hunting skills, the geological know-how to find stone and other necessary materials and been ready for new challenges,” David Meltzer, study author and archaeologist from the Southern Methodist University in Texas, said in a statement.
"The dogs that accompanied them as they entered this completely new world may have been as much a part of their cultural repertoire as the stone tools they carried."
Reported in the journal Proceedings of the National Academy of Sciences, the new study saw an international team of archaeologists led by Durham University look closely at archaeological evidence and genetics from humans and dogs in Siberia, Beringia (a now-submerged land bridge connecting Alaska to Siberia), and North America to trace the history of dog lineages.
The findings suggest that all ancient dogs in the Americas belonged to a single haplogroup lineage, A2b, which can be traced back to a coalescence event some 15,000 years ago. Considering the A2b haplogroup is almost totally absent from outside of the Americas, the researchers argue that this can be interpreted as a lower bound for divergence between American and Siberian dogs.
"The only thing we knew for sure is that dog domestication did not take place in the Americas," explained co-author Laurent Frantz, a geneticist from Ludwig Maximilian University, Munich. "From the genetic signatures of ancient dogs, we now know that they must have been present somewhere in Siberia before people migrated to the Americas.”
"Dog domestication occurring in Siberia answers many of the questions we've always had about the origins of the human-dog relationship," lead author Dr Angela Perri said, but some questions do remain.
How did humans develop such a tight bond with these canine predators? The researchers from this study suggest it might have something to do with the fierce climatic conditions and scarce resources seen during the Ice Age, which brought dog ancestors and humans into close proximity over competition for food. A study published earlier this month attempted to dig deeper into this question, suggesting that the bond developed through humans sharing leftover food with the wild dogs during this harsh time.
