Breakthrough in Peopling of the Americas Finds a Female Lineage from China

A groundbreaking new study has harnessed the power of mitochondrial DNA to trace a marvelous female lineage from northern coastal China all the way to the Americas. This has revealed compelling evidence of not one, but two migrations, during the last Ice Age, and the subsequent melting period! This discovery challenges previous beliefs about the ancestry of Native Americans and sheds new light on the complicated history of human migration and settlement in the Americas.

Coinciding with the timeline of the second migration is another branch of the same lineage migrating to Japan. This is a potential explanation for Paleolithic archaeological similarities between the Americas, China, and Japan, explains the study published in the latest edition of Cell Reports.

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A Complicated Ancestry: Tracing Lineage

It has popularly been believed that ancient Siberians, who crossed over a land bridge in the Bering Strait linking modern Russia and Alaska, were the sole ancestors of Native Americans. This accepted wisdom is now being challenged in many ways, thanks to newer and newer scientific studies, like this. The new science heavily points towards multiple waves of human migration from various parts of Eurasia to the Americas.

"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."

A team of researchers from the Chinese Academy of Sciences embarked on a quest to trace a lineage that could potentially connect East Asian Paleolithic populations to the founding populations in Chile, Peru, Bolivia, Brazil, Ecuador, Mexico, and California.

This lineage, crucially present in mitochondrial DNA, provides a unique window into tracing kinship through the maternal line, according to a press release. The lineage, known as D4h, was used in the research, allowing the team to trace maternal ancestry over the course of 10 years.

The research team from the Kunming Institute of Zoology embarked on an extensive analysis of over 100,000 contemporary and 15,000 ancient DNA samples collected across Eurasia. This led them to the identification of 216 contemporary and 39 ancient individuals belonging to this rare lineage. After a thorough comparison of accumulated genetic mutations, geographical locations, and carbon dating, the researchers successfully traced the lineage's branching trajectory.

Maternal ancestry from Chinese and Japanese lineages (D4h1a and D4h2) was traced in the study, showing Paleolithic archaeological similarities among Northern China, the Americas, and Japan. (Cell Reports)

Two Migration Events: Changing the Timeline

Evidence of two migration events from northern coastal China to the Americas emerged – the first of these occurred roughly between 19,500 and 26,000 years ago, during the Last Glacial Maximum. Potentially, the severe ice sheet coverage in northern China (at its peak) rendered the region inhospitable for human habitation during this period.

The second migration unfolded during the subsequent deglaciation or melting period, spanning from 19,000 to 11,500 years ago, a period of relative warming. The favorable climatic conditions during this phase likely contributed to a rapid population increase, causing (perhaps even forcing) an expansion of human communities into other geographical regions. It is likely that both groups arrived in the Americas via the Pacific coast, rather than venturing through the inland ice-free corridor, which would not have been accessible during that time, reports The Daily Mail.

During this deglaciation period, another group branched off from northern coastal China and made their way to Japan, forging an intriguing connection. "We were surprised to find that this ancestral source also contributed to the Japanese gene pool, especially the indigenous Ainus," says Li.

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Similarity In East and West Technology Explained

This serves as a solid explanation for the archaeological similarities observed among the Paleolithic peoples of China, Japan, and the Americas. This is observed particularly in their shared crafting techniques for stemmed projectile points used in 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.

Pre-historic Native American projectile points. Study suggests shared crafting techniques between Chinese, Japanese, and American cultures. ($1LENCE D00600D/CC BY-SA 3.0)

Although the focus of the study primarily centered on mitochondrial DNA, complementary evidence from Y chromosomal DNA further indicates the presence of male ancestors of Native Americans in northern China during the same period as their female counterparts.

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

Top image: Native Alaskan Eskimo woman - could have Chinese lineage.   Source: Agnieszka/Adobe Stock

By Sahir Pandey