Dogs are loved in American culture. Countless hours are devoted to finding the best products for little ones, suffocating with treats and worrying about how they can deal with the separation anxiety.
But what was life like before dogs became man’s best friend? manner before? The ancient history of dog domestication is obscure, especially as far as the arrival of the first dogs in the Americas is concerned.
Did dogs come to the Americas with the first humans, or did they come later? A new study provides an answer.
What’s new – Research published in the journal on Tuesday Proceedings of the Royal Society B genetically confirmed the oldest dog remains found in the Americas. The femur in question is approximately 10,150 years old.
These new results surpass the oldest previously confirmed U.S. dog remains by about 240 years.
This finding suggests that dogs travel to America with the first humans, specifically via a coastal route that followed the Cordilleran ice sheet. It began to retreat about 17,000 years ago, enabling humans to migrate to the Americas with their dogs.
“Our study suggests that dogs participated in this initial migration,” said co-author Charlotte Lindqvist, an associate professor at the University of Buffalo. Reverse.
Previous researchers theorized dogs by a continental route to the Americas and migrated westward to the Pacific coast. This new study loosens the idea.
How they did it – Researchers analyzed a dog’s femur bone discover an Alaska cave known as Lawyer’s Cave.
The scientists compared this Alaska surplus with data from modern dog breeds, historic Arctic dogs and pre-contact dogs. These are dogs that lived in the Americas before European colonization.
Cave explorers discovered this ancient Alaska remnant decades ago. Originally, scientists suspected that the femur bone belonged to a bear, but it was later confirmed that it belonged to a dog.
“There are few finds of ancient bone remains of humans as well as dogs in the New World,” says Lindqvist.
Based on limited archaeological findings, some researchers have previously assumed that dogs arrived in humans in the Americas.
“However, based on the relatively little physical evidence we have, dog remains are not older than about 10,000 years old,” Lindqvist explains. It “hangs behind the oldest human remains older than 12,000 years, and archaeological artifacts that are even older,” she says.
The genetic analysis of ancient Alaska dog remains – identified in the study as PP-00128 – refutes these previous assumptions.
Finally the team wanted to know when this old Alaska dog is genetically determined of dogs that are in contact. The timing of this genetic disorder can be estimated from DNA data “based on the assumption that genetic changes occur in a clockwise manner,” Lindqvist says.
Go into the details – The scientists learned that the ancient Alaska dog had a common ancestor with dogs before contact, but the Alaska animal deviated from the genetic lineage about 14,500 years ago. It also deviated from Siberian dogs about 16,000 years ago.
This deviation from Siberian dogs also coincides with the period when researchers thought that the Cordilleran ice sheet had melted, which would allow humans and dogs to cross to the Americas via the Pacific Ocean.
This finding contradict directly previous research.
“Previous genetic estimates of the distribution between pre-European American dogs and their Siberian ancestor were younger than the estimates when the ancestral Native American human population deviated from their Siberian ancestors,” Lindqvist says. The version of history suggests that dogs arrived in later migrations of humans to the Americas.
However, the finding of another old man near the Alaska monster probably confirms the hypothesis of this team: Ancient dogs and humans arrived in the Americas together.
Research suggests that pre-contact dogs began to decline in numbers about 2,000 years ago, coinciding with the arrival of Europeans to the mainland. European dog breeds, coupled with the emergence of sled dogs used by the Inuit people, effectively wiped out most pre-contact dog breeds.
Isotope detection also indicates that the old Alaska dog had a diet that looked more like marine mammals or people living in southeast Alaska. The researchers speculate that it may have digested salmon – also known as ‘dog salmon’, which further illustrates how the diet of ancient humans influenced the nutrition of dogs.
Why it matters – The scientists acknowledge that these results have some caveats.
“There is a gap in timing between genetic estimates and the actual physical remains we have of both dogs and humans, which also leads to an uncertainty about when humans and dogs first migrated,” Lindqvist says.
Despite these uncertainties, the study still provides insight into where and how the first humans migrated to the Americas.
“There has long been a controversy over whether the first humans migrated to the Americas south of the ice plants through a continental corridor between the ice sheet or along the North Pacific coast,” Lindqvist says.
It is possible that these findings, coupled with recent research on melting ice sheets, may resolve this dispute.
“We now have evidence that the coastal edge of the ice sheet began to melt at least about 17,000 years ago, while the inland passage was only viable about 13,000 years ago,” Lindqvist says.
“The coastal route for the first Americans seems likely.”
What’s next – According to the study, there may be higher amounts of pre-contact canine descent in modern dogs than previously thought. Modern dogs are grouped into four large haplotype groups, Lindqvist explains. Pre-contact dogs are haplotype A.
Previously, researchers found a slight genetic overlap between pre-contact dogs and seven modern dogs. In this study, researchers also found an Alaskan Eskimo dog with a completely different pre-contact pedigree compared to other modern dogs.
The genetic analysis of the ancient Alaska dog, PP-00128, suggests that it is “up to the sex of the dog before contact, but its position in this generation is the means of diversifying most pre-contact dogs,” Lindqvist says.
“This indicates that it is a closer relative to the ancestor of the dogs before contact and that it belongs to an early generation of dogs before contact.”
More research is needed to know for sure. But we do know that the story of the Americas is in a way a story of dogs. The initial human habitation included dog company – and it’s a service worthy of some applause.
Abstract: The oldest confirmed remains of domestic dogs in North America come from archaeological sites in the middle continent that were calibrated about 9900 years before the time (cal BP). Although this date suggests that dogs may not have arrived with the first Native Americans, the timing and routes for New World dog access are unclear. Here we present a complete mitochondrial genome of a dog from Southeast Alaska, dated at 10 150 ± 260 calBP. We compared this high coverage genome with data from modern dog breeds, historic Arctic dogs and American contact dogs (PCDs) before European arrival. Our analyzes show that the old dog shared a common ancestor with PCDs that lived about 14,500 years ago and deviated from Siberian dogs about 16,000 years ago, and this coincided with the minimum proposed date for the opening of the Northern Pacific Coast Route (NPC) along the Cordilleran Ice Sheet and genetic evidence for the native population of the Americas. This ancient Southeast Alaskan dog occupies an early branching position within the PCD clade, indicating that it is a relative of the earliest PCDs brought with them from East Beringia southward along the NPC to the rest of the America is migrating. The stable isotopeδ13C value of this early dog indicates a marine diet, unlike the terrestrial diet of the younger mid-continent PCDs. Although PCDs have been largely replaced by modern European dog breeds, our results indicate that their population decline began around 2000 years BP, coinciding with the expansion of the Inuit peoples, associated with traditional sled dog culture. Our findings suggest that dogs were part of the initial human habitation of the New World, and provide insight into its replacement by both Arctic and European generations.