A new study published in Cell Reports suggests that the ancestors of Native Americans were not solely ancient Siberians who crossed over the land bridge that once existed in the Bering Strait, linking modern-day Russia and Alaska. Instead, some of the first Native American arrivals came from China during two distinct migrations: the first during the last ice age, and the second shortly after. The research, conducted by the Kunming Institute of Zoology, involved analyzing 100,000 modern and 15,000 ancient DNA samples across Eurasia to identify the mitochondrial DNA lineage known as D4h, which is found in ancient human remains across the Americas, including Bolivia, Brazil, Chile, Ecuador, Mexico, and California. The study identified 216 contemporary and 39 ancient individuals who belonged to the ancient lineage and examined the mutations that had accumulated over time. The results revealed two migration events, both of which involved seafarers who docked in America and traveled along the Pacific coast by boat. The second migration was also notable for a subgroup that branched out from northern coastal China to Japan, contributing to the indigenous Ainu. The findings suggest that northern coastal China served as a genetic reservoir contributing to the Native American gene pool, and that Japan shares similarities with prehistoric people in the Americas and China.