Ancient China link in peopling Americas

The question of when people went to the Americas has long intrigued scientists. And now a new genetics study says some of the first were from China.

A study in Cell Reports revealed two migration events: between 19,500 and 26,000 years ago, when sheet ice coverage was at its greatest in northern China, and during the melting period from 19,000 to 11,500 years ago.

"Our findings indicate that besides the previously indicated ancestral sources of Native Americans in Siberia northern coastal China served as a genetic reservoir," said Li Yuchun, one of the study's authors.

Li added that during the second migration the same lineage of people settled in Japan, which could help explain similarities in prehistoric arrowheads and spears found in China, Japan and the Americas.

It was believed Siberians were the sole ancestors of Native Americans.

But research from the late 2000s has signaled more diverse sources from Asia could be connected to a lineage responsible for founding populations across the Americas. Known as D4h, this lineage is found in mitochondrial DNA, inherited from mothers.

A team from the Kunming Institute of Zoology combed through 100,000 modern and 15,000 ancient DNA samples across Eurasia to reconstruct D4h origins and expansion.