In other words, the 16,700-year mark may represent the point at which their genetics diverged but may not necessarily be the point at which the populations split apart-so that timestamp can’t be used to say when domesticated dogs first entered the Americas. Dogs from both groups likely shared a common ancestor many generations earlier, long before they went their separate ways. Unless there were very few dogs around to begin with, the dog populations that remained in Siberia shouldn’t all have had the same mother as the dogs from the American populations, says Krishna Veeramah, a population geneticist at Stony Brook University who wasn’t involved with the new work. The multidisciplinary team’s analysis suggested the dog belonged to a lineage that split with its Siberian canine cousins no earlier than 16,700 years ago-roughly the time humans may have been traveling into North America along the coast.īut even this moment in time may not represent the point at which some Siberian dogs first followed humans into the Americas. But its mitochondrial DNA-a small fraction of the entire genome inherited only from the maternal line-was retrieved.
While genetic analysis proved that PP-00128 did not belong to a bear, extraction of the dog’s complete nuclear DNA profile wasn’t possible from the tiny bone fragment. One bone, specimen PP-00128, originally excavated from the site of Lawyer’s Cave on Alaska’s Blake Channel, was thought to belong to one. Charlotte Lindqvist, an evolutionary biologist at the University at Buffalo and co-author of the new study, was interested in what bears were up to back then. ( Ancient wolves that played with humans likely evolved into today's friendly dogs.)Īs part of a multidisciplinary research project looking into the stories of the animals, climate, and environment of the region as the ice cover invaded and retreated, scientists are unspooling the genetics of bones excavated in the region, including those kept at the University of Alaska museum. These wolves gradually became domesticated dogs sometime between about 40,000 and 19,000 years ago. That means that dogs were coming to America much earlier than this-but when did they first arrive?Īccording to recently unveiled genetic evidence, around the time when a third of North America was buried beneath ice during the Last Glacial Maximum (LGM) roughly 26,500 to 19,000 years ago, people had increasing encounters with gray wolves in Siberia, where comparatively temperate refuges provided prey both could hunt down and eat. But archaeologists are more interested in the fact that we now have very similarly aged dogs in two very different parts of North America. With a difference of a mere couple centuries, the title of “oldest” now just barely belongs to the Alaskan pup PP-00128. Back in 2018, the burial sites of several dogs in Illinois were found to be around 9,910 years old. While this is the oldest physical evidence for domesticated dogs in the Americas, the femur fragment doesn’t necessarily belong to one of the first dogs to make it over from northeast Asia. “Even if you can’t imagine anything about the life of people 10,000 years ago, you can still understand the relationship between people and their dogs,” says Carly Ameen, a zooarchaeologist at the University of Exeter who wasn’t involved with the new work. The analysis of the oldest domesticated dog remains yet discovered in the Americas, published today in Proceedings of the Royal Society B, not only provides important clues to when dogs first entered the Americas, and the routes they took alongside humans to get here, but it also reinforces the very long and deep bond between people and domesticated dogs.
Recent genetic testing of the sample, however, proved to be a surprise to scientists-but perhaps not dog owners: PP-00128 once belonged to a loyal canine companion who trotted alongside humans into the icy new world of the Americas around 10,150 years ago. The femur fragment, small enough to hold between two fingers, had been excavated from a site along the southeastern Alaskan coast where archaeologists also uncovered the remains of fish, birds, mammals, and humans going back thousands of years.
For about 20 years, specimen PP-00128 in the earth sciences collection of the University of Alaska Museum was thought to belong to a rather old bear.