A groundbreaking genetics study has suggested that Native Americans have a more diverse ancestral source from Asia.
Published in the journal Cell Reports
, the study from Kunming Institute of Zoology
unveiled evidence of human migrations from China to the Americas and Japan during the Ice Age.
The findings challenge the previously held belief that ancient Siberians were the sole ancestors of Native Americans.
The study involved the team meticulously examining 100,000 modern and 15,000 ancient DNA samples from across Eurasia over the course of 10 years.
Researchers were able to trace the samples’ maternal ancestry by focusing on a specific lineage known as D4h, found in mitochondrial DNA inherited exclusively from mothers.
The team ultimately identified 216 contemporary and 39 ancient individuals linked to the ancient D4h lineage.
By analyzing accumulated mutations and geographic locations of the samples, as well as employing carbon dating techniques, the researchers were able to reconstruct the origins and expansion history of the D4h lineage.
The study’s findings indicated two distinct migration events, with the first migration occurring between 19,500 and 26,000 years ago.
That migration coincided with the Last Glacial Maximum, a period of extensive ice sheet coverage and inhospitable climate conditions in northern China.
The second migration took place during the melting period, approximately 19,000 to 11,500 years ago. This event was purportedly triggered by increasing human populations.
It is suggested that during both migrations, seafaring travelers reached the Americas and traveled along the Pacific coast by boat, as the “inland ice-free corridor” in modern Canada was still inaccessible.
The study also revealed a subgroup branching out from northern coastal China to Japan during the second migration. This finding aligns with archaeological similarities found between ancient populations in the Americas, China and Japan, and could help explain resemblances in prehistoric arrowheads and spears discovered across these regions.
Yu-Chun Li, one of the report’s authors, emphasized the significance of the study’s large sample size and the complementary evidence from Y chromosomal DNA, which indicated that male ancestors of Native Americans resided in northern China concurrently with their female counterparts.
“However, we don’t know in which specific place in northern coastal China this expansion occurred and what specific events promoted these migrations,” he was quoted saying. “More evidence, especially ancient genomes, are needed to answer these questions.”