Advanced genetic testing of some of North and South America's most controversial human remains is changing what we know about how ancient humans behaved and ultimately came to inhabit the region, potentially rewriting historical timelines as we know them.
Published today in Science, the study genetically analyzed DNA recovered from 15 ancient genomes discovered across the Americas, from Alaska to Patagonia. The results from two particularly contentious mummies can now dismiss a theory that Paleoamericans – a group of genetically different humans – existed in North America before Native Americans.
When Danish explorer Peter W. Lund discovered the Lagoa Santa remains in the 19th century, his researchers came up with the “Paleoamerican hypothesis” to suggest that the group of skeletons were not Native Americans due to their different cranial morphology. A century later, the remains of a 40-year-old man who died 10,600 years ago were found in Spirit Cave in the US Great Basin Desert and for nearly two decades, the “Spirit Cave Mummy” was at the heart of a legal battle. Nevada’s Fallon Paiute-Shoshone Tribe claimed cultural affiliation with the remains and requested they be repatriated under the Native American Graves Protection and Repatriation Act. The federal government refuted their claim, contending the remains were genetically different than Native Americans.
That’s where Copenhagen-based researcher Eske Willeslev came in. As part of an international study, Willeslev was already sequencing other contentious remains (like the Lovelock skeletons, an Inca mummy, Chilean Patagonia's oldest human remains, as well as the 9,000-year-old milk tooth from a young Alaskan girl) when the Fallon Paiute-Shoshone Tribe granted him permission to analyze the Spirit Cave Mummy.
"Spirit Cave and Lagoa Santa were very controversial because they were identified as so-called 'Paleoamericans' based on craniometry – it was determined that the shape of their skulls was different to current day Native Americans,” said author Eske Willeslev in a statement. “Our study proves that Spirit Cave and Lagoa Santa were actually genetically closer to contemporary Native Americans than to any other ancient or contemporary group sequenced to date."
His findings not only confirmed the Spirit Cave Mummy was of Native American descent, resulting in the eventual reburial of his remains, but also shed light on other areas of ancient human life.
"A striking thing about the analysis of Spirit Cave and Lagoa Santa is their close genetic similarity which implies their ancestral population travelled through the continent at astonishing speed," said anthropologist David Meltze, from Southern Methodist University. This is something researchers have long suspected but weren’t able to confirm through genetic testing.
“These findings imply that the first peoples were highly skilled at moving rapidly across an utterly unfamiliar and empty landscape. They had a whole continent to themselves and they were traveling great distances at breath-taking speed,” added Meltzer. Not only did they have a case of wanderlust, but the ancient people were also much more social than previously thought, often breaking away from their larger groups to travel, trade, and socialize with other tribes.
Also of interest was the discovery of an Australasian gene in ancient South American Natives but not found in North American Natives, which means groups carrying the gene were either already present and later disappeared or had arrived later.