Perhaps, as Davis and different archeologists recommend, these folks got here from northeast Asia by boat, transferring south alongside the Pacific shoreline and establishing camps alongside the way in which. “The Pacific coast is the most likely candidate—it seems like it would have had areas of exposed and habitable land between about 17,000 and 16,000 years ago,” says Geoffrey M. Smith, government director of the Great Basin Paleoindian Research Unit on the University of Nevada Reno, who wasn’t concerned within the new analysis. “It may have been more short trips in some sort of watercraft between exposed and habitable patches along the coast.”

But this state of affairs presents some archeological challenges: First, there aren’t any boat artifacts from this era that’d recommend folks had the expertise to get from Asia to the Americas by sea. (That’s to not say the boats didn’t exist. Humans bought from Asia to Australia 60,000 years in the past, Davis says, which might presumably require long-range boating.) And because the world transitioned into the hotter local weather we take pleasure in immediately, all that ice melted and drove up sea ranges, shifting the Pacific shoreline and submerging any potential artifacts. 

Why precisely folks would have made the journey can be an open query—and maybe an unanswerable one. “It’s hard to know what motivated people to make that move from Northeastern Asia to Northwestern North America,” says Smith. “Those areas were connected by land, so it wasn’t like people said, ‘OK, we’re getting in this boat and we’ll never see you again.’” Instead, it may have been rather more of an natural, gradual course of by which folks crept down the Pacific shoreline, sustaining contact with Asian communities.

Davis and his colleagues don’t know if the teams from Japan and the Americas had been genetically associated—they don’t have the genetic materials to truly again up such a idea. But the similarity of the projectile factors every group produced may recommend a kind of historical social community, the sharing of expertise. “It doesn’t matter, necessarily, if their genetics are the same,” says Davis. “You meet somebody from some other part of the world and you’re holding an iPhone, you have the same technology as that person—it doesn’t mean you’re genetically related.”

It would make sense that as people flowed from Asia to the Americas, they’d use comparable projectile factors. “By bringing in the northern Japan connection, we’ve got a pretty good hypothesis about linking up Old and New World assemblages in a comparable time period,” says David Hurst Thomas, senior curator in residence of North American archaeology on the American Museum of Natural History, who wasn’t concerned within the analysis. It’s an early idea that’ll want critiquing and additional proof, he provides, “but I think it’s groundbreaking.”

Davis additionally thinks this will not have been a singular connection between Asia and the Americas throughout that point interval. Perhaps after these folks introduced the data of the projectile factors with them on their journey, different teams stored coming, holding the ocean-spanning technological community alive—including extra intriguing wrinkles to the enormously sophisticated historical past of the peopling of the Americas. “It’s hard to know much about how such a network operated over time and space with only two far-apart data points,” says Davis of the artifacts found in Japan and Idaho. “But it’s a place to start.”