The indigenous people of Southeast Alaska and British Columbia have a tradition of invoking their longevity in that region as going back to a time before memory.
Now DNA evidence backs up that claim, and gives more specifics about how far back the Tlingit, Haida and Tsimshian people can trace their ancestry.
Analysis of genetic material from the remains of an ancient skeleton shows links with Northwest Native people that go back more than 10,000 years.
"It confirms our oral tradition that we have lived and occupied and owned Southeast Alaska since time immemorial," said Rosita Worl, a Tlingit anthropologist and president of the Sealaska Heritage Institute, a nonprofit dedicated to preserving the Native cultures of Southeast Alaska.
The analysis, detailed in a study published in the Proceedings of the National Academies of Science, used DNA from the 10,300-year-old skeletal remains found in 1996 in a cave on Prince of Wales Island.
After the discovery of the skeleton, the individual was named Shuká Káa, meaning "Man Ahead of Us."
Identified as a male who was in his 20s when he died and who relied on a fish-heavy diet, according to isotope analysis, Shuká Káa is considered an important contributor to knowledge about humans who migrated to North America along the coast, rather than over the Bering Land Bridge.
But when his remains were discovered, it was unclear whether Shuká Káa was an ancestor of modern Tlingit, Haida and Tsimshian people, said Worl, one of the study's 16 co-authors.
"At that point, we could not say conclusively that the individuals living in Southeast Alaska had a demonstrative tie to him," she said.
Now that matter has been settled — and with some information that helps fill in details about which regional Native tradition. "The 'time immemorial' doesn't signify a date, but it signifies current occupation," Worl said.
The genetic link is not simple. The study used analysis of both mitochondrial DNA, which is passed maternally through generations, and nuclear DNA, which includes both maternal and paternal genes.
Shuká Káa's most direct link was with the 6,075-year-old remains of another individual found on Lucy Island off the coast of British Columbia. Shuká Káa shared mitochondrial DNA with that individual, but not with two other individuals whose remains were also found in British Columbia. Shuká Káa's link to those two individuals, about 2,500 and 1,750 years old, was through nuclear DNA, the study found.
The mitochondrial DNA present in Shuká Káa and the 6,075-year-old skeleton was not found elsewhere and seemed to disappear, another co-author said.
"The nuclear DNA suggests that this is probably not about population replacement, but rather chance occurrence through time," University of Oklahoma anthropology professor Brian Kemp said in a statement released by Sealaska Heritage. "If a female has no children or only sons, the mitochondrial DNA is not passed to the next generation. As a male, Shuká Káa could not have passed on his own mitochondrial DNA; he must have had some maternal relatives that did so."
The team did not find any genetic tie between Shuká Káa and Arctic peoples — Inuit or Yup'ik — but there was some relationship with remains found in South America.
That was a bit of a surprise, Worl said. "We were kind of laughing among ourselves and we said, 'Oh, we have relatives in South America,' " she said.
The site that held Shuká Káa's remains, called On Your Knees Cave, was found in 1993 when the U.S. Forest Service was studying the area in advance of a proposed Tongass National Forest timber sale. Along with the partial skeleton were several cultural artifacts.
The discovery of Shuká Káa and the collaborative scientific work that flowed from it contrasted with the case of a different discovery of ancient human remains, those of 8,545-year-old Kennewick Man in Washington state.
Kennewick Man, also called The Ancient One, was found along the Columbia River in 1996, the same year that Shuká Káa was found. That discovery touched off several years of fights between archaeologists and the region's Native tribes. The dispute was only recently resolved, when tribes, with the help of an act of Congress, reburied the remains in February.
In the case of Shuká Káa, Worl said, the scientists made special efforts to consult and cooperate with the region's indigenous people. Local people allowed and participated in the research, she said. "It was felt that Shuká Káa had offered himself for study," she said.
Shuká Káa's remains were buried on Prince of Wales Island in a 2008 tribal ceremony. The DNA used for the study had been extracted from a tooth prior to that burial.