First ‘Americans’ likely arrived 26,000 years ago — 10,000 years earlier than scientists thought

KUNMING, China — Humans may have arrived in the Americas up to 26,000 years ago, about 10,000 years earlier than previously thought, according to new research. Scientists have discovered evidence of Ice Age migrations from the coast of northern China.

“The Asian ancestry of Native Americans is more complicated than previously indicated,” says first author Yu-Chun Li, a molecular anthropologist at the Chinese Academy of Sciences. “In addition to previously described ancestral sources in Siberia, Australo-Melanesia, and Southeast Asia, we show that northern coastal China also contributed to the gene pool of Native Americans.”

Li’s team traced a female lineage by analyzing mitochondrial DNA, which is passed from mothers to their offspring. They identified two migration events: the first between 19,500 and 26,000 years ago during the Last Glacial Maximum, when ice sheet coverage was at its greatest and conditions in northern China were likely uninhabitable. The second occurred during the subsequent melting period between 19,000 and 11,500 years ago. This coincided with a rapid increase in populations due to the improved climate, which may have fueled human expansion into other geographical regions.

In both cases, the travelers likely reached America via the Pacific coast rather than by crossing an inland ice-free corridor, which would not have been open at the time. The researchers also uncovered an unexpected genetic link between Native Americans and Japanese people. During the deglaciation period, another group branched out from northern coastal China and went to Japan.

“We were surprised to find that this ancestral source also contributed to the Japanese gene pool, especially the indigenous Ainu,” says Li in a media release.

Who are the Ainu?

The Ainu now live mostly on Hokkaido, the northernmost island, but their lands once spanned from northern Honshu to Sakhalin and the Kuril Islands, now a disputed part of the Russian Federation. The Ainu have long been of interest to anthropologists due to their unique cultural, linguistic, and physical identity.

It was long assumed Native Americans descended from Siberians who crossed the Bering Strait’s temporary land bridge. However, the study in Cell Reports adds to a growing body of recent genetic, geological, and archaeological evidence that multiple waves of humans journeyed to the Americas from various parts of Eurasia. The research connects East Asian Paleolithic populations to founding groups in Chile, Peru, Bolivia, Brazil, Ecuador, Mexico, and California.

The researchers analyzed over 115,000 DNA samples from across Eurasia and eventually identified 216 contemporary and 39 ancient individuals belonging to the rare lineage. Comparing accumulated mutations, geographic locations, and carbon-dated ages of each allowed them to map a branching path. This discovery helps explain archaeological similarities between the Paleolithic peoples of China, Japan, and the Americas, specifically in primitive technologies for crafting arrowheads and spears.

“This suggests that the Pleistocene connection among the Americas, China, and Japan was not confined to culture but also to genetics,” says senior author Qing-Peng Kong, an evolutionary geneticist at the Chinese Academy of Sciences.

The results were supported by an analysis of Y chromosomal DNA, suggesting male ancestors of Native Americans also lived in northern China around the same time as these females. This research fills another piece of the Native American puzzle.

“The origins of several founder groups are still elusive or controversial,” says Kong. “Next, we plan to collect and investigate more Eurasian lineages to obtain a more complete picture of the origin of Native Americans.”

You might also be interested in:

• The first Americans? First humans to arrive in North America may have lived 30,000 years ago
• Meet the first Neanderthal family: Ancient genomes of 13 prehistoric humans show they were just like us
• Earliest evidence of humans? Remains found in east Africa 30,000 years older than thought

South West News Service writer Mark Waghorn contributed to this report.