Some 10,300 years ago, a man known as Shuká Káa lived on the Pacific Northwest Coast, presumably hunting bears and feasting on fish. Archaeologists discovered his remains in a southeastern Alaskan cave in 1996, and tried to link a sample of mitochondrial DNA to members of modern indigenous peoples who live in the geographic area where Shuká Káa was found. They weren't able to find a match, and Shuká Káa was given a ceremonial burial in 2008. But that wasn’t the end of Shuká Káa's story.
Last month, Ann Gibbons reported for Science that scientists got permission from several Native American tribes to re-analyze Shuká Káa’s remains using more sophisticated methods of DNA sequencing. They found that the seafarer was related to the Tsimshian, Tlingit, Nisga’a and Haida peoples living in the Pacific Northwest today, indicating that modern native groups living in the region have longstanding links to its first inhabitants.
The study, published in the Proceedings of the National Academy of Sciences, sought to revise earlier genetic research of Shuká Káa, which focused on mitochondrial DNA. As Diana Yates explained in a University of Illinois press release, mitochondrial DNA, or mtDNA, occurs outside of cells’ nucleus and is passed from mothers to their children. But mtDNA does not provide a complete genetic picture.
“Mitochondrial DNA just traces the maternal line—your mother’s mother’s lineage—so, you’re missing information about all of these other ancestors,” John Lindo, a postdoctoral researcher and one of the authors of the study, told Yates.
Nuclear DNA, the team theorized, would allow them to make a more comprehensive assessment of Shuká Káa’s lineage. So they set about extracting nuclear DNA from Shuká Káa’s molars, where his last tissue remains. They also analyzed the teeth of three individuals found on the coast of British Columbia, who lived between 6,075 to 1,750 years ago.
As Gibbons explained in Science, researchers were only able to sequence about 6 percent of Shuká Káa’s genome, since his DNA was quite damaged. They proceeded to compare those markers to the DNA of the three younger skeletons, and to the DNA of 156 indigenous groups living in various locations across the globe.
Researchers’ analysis revealed that Shuká Káas closely related to the three skeletons found along the coast of British Columbia. And those three skeletons are in turn closely related to the Tsimshian, Tlingit, and other indigenous peoples of the Pacific Northwest. Piecing together this genetic puzzle, scientists concluded that Shuká Káa was a common ancestor, and that “the Pacific Northwest Coast exhibits genetic continuity for at least the past 10,300” years, as the authors of the study wrote.
The study also indicated that there were at least two genetically distinct groups living in the Americas 10,000 years ago, as researchers found that Shuká Káa was not a close relative of the Anzick Child, who was buried some 12,700 years ago in what is now Montana. “[I]t suggests that the peopling of the Americas was more complex than most people think,” Ripan Malhi, the lead author of the study, said in an interview with Aaron Bolton for KSTK News.
The oral tradition of Pacific Northwest indigenous groups speaks of an ancestral presence in the region “since time immemorial,” Rosita Worl, study co-author and the director of the Sealaska Heritage Institute, told Yates. The new study of Shuká Káa adds to a growing body of evidence confirming that the groups' ties do indeed stretch back to some of the earliest inhabitants of the land.