Humans arrived in the Americas 10,000 years earlier than previously thought

A groundbreaking new study suggests that the migration of ancient humans to the Americas occurred 26,000 years ago, a full 10,000 years earlier than previously believed. 

The research, carried out by scientists from the Chinese Academy of Sciences, provides evidence that the first migrants originated from the northern coastal region of China, debunking the longstanding theory that ancient Siberians who crossed the Bering Strait land bridge were the sole ancestors of Native Americans.

The team of researchers, led by molecular anthropologist Dr. Yu-Chun Li, traced a female lineage by analyzing mitochondrial DNA, which is inherited from mother to offspring. They discovered links between East Asian Paleolithic-age populations and founding populations in Chile, Peru, Bolivia, Brazil, Ecuador, Mexico, and California. 

Multiple migration events discovered

The study also unveiled another migration event that took place 19,500 years ago, which saw a rapid population increase due to an improved climate.

“The Asian ancestry of Native Americans is more complicated than previously indicated,” explained Dr. Li. “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.” 

The research focused on the D4h lineage, which allowed the team to trace maternal ancestry over a decade.

How the study was done

The scientists analyzed 100,000 modern and 15,000 ancient DNA samples from across Eurasia, eventually identifying 216 contemporary and 39 ancient individuals from the D4h lineage. 

By examining mutations that had accumulated over time, considering the samples’ geographic locations, and employing carbon dating techniques, the researchers reconstructed the origins and expansion history of the D4h lineage.

This discovery sheds light on the archaeological similarities between the Paleolithic peoples of China, Japan, and the Americas. 

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

What the researchers learned

The results revealed two distinct migration events. The first took place between 19,500 and 26,000 years ago during the Last Glacial Maximum, when ice sheet coverage was at its peak and climate conditions in northern China were likely unfavorable. 

The second migration occurred during the melting period, between 19,000 and 11,500 years ago, with increasing human populations possibly triggering these migrations.

Interestingly, the study found a surprising genetic link between Native Americans and Japanese people, particularly the indigenous Ainu. 

During the melting period, a subgroup from northern coastal China migrated to Japan, contributing to the Japanese population. This finding aligns with archaeological similarities between ancient peoples in the Americas, China, and Japan.

What makes the researchers so confident in their results

Dr. Li highlighted the strength of the study, noting the large number of samples they discovered and the complementary evidence from Y chromosomal DNA that showed male ancestors of Native Americans lived in northern China at the same time as the female ancestors. 

However, he added that “more evidence, especially ancient genomes, are needed to answer” questions about the specific location in northern coastal China where this expansion occurred and the events that promoted these migrations.

This study adds another piece to the puzzle that is Native American ancestry, but many other elements remain unclear. 

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

More about human migration across the Earth

Human migration has been a significant aspect of our species’ history, shaping the cultural, linguistic, and genetic diversity observed today. Various factors, such as climate change, the search for resources, and the desire to explore, have driven human migration throughout history. Here are some key findings about human migration across the Earth:

Out of Africa

Genetic and archaeological evidence suggests that modern humans (Homo sapiens) first originated in Africa, particularly East Africa, around 200,000 to 300,000 years ago. Between 70,000 and 50,000 years ago, a small group of humans left Africa and began migrating across the globe.

Into Eurasia

The first wave of migration saw Homo sapiens spread across Eurasia, where they encountered and interbred with other hominid species like Neanderthals and Denisovans. This interbreeding has left traces of Neanderthal and Denisovan DNA in the genomes of non-African populations.

Peopling of Australia

Around 50,000 to 65,000 years ago, humans reached the Australian continent, which was connected to New Guinea through a land bridge during the Last Glacial Maximum. The indigenous populations of Australia and Papua New Guinea have been largely isolated from the rest of the world since then.

Spread into Europe

Modern humans began to populate Europe around 45,000 years ago, replacing the Neanderthals who had lived there for thousands of years. This migration was facilitated by the development of new tools and the ability to adapt to changing environments.

The Americas

As mentioned earlier in this article, recent evidence suggests that humans reached the Americas around 26,000 years ago. Migrations occurred through the Bering land bridge that connected Siberia to Alaska during periods of low sea levels. Over time, these migrants spread across North and South America, forming diverse Native American populations.

The Pacific Islands

The settlement of the remote Pacific Islands began around 3,500 years ago by the Austronesian peoples. They developed sophisticated navigational skills and embarked on long sea voyages to populate islands such as Fiji, Tonga, Samoa, and eventually Hawaii, Easter Island, and New Zealand.

Human migration in the last few millennia

Over the past few thousand years, large-scale migrations, invasions, and the spread of empires have continued to shape human populations. Examples include the migration of Bantu-speaking peoples across Africa, the spread of Indo-European languages across Europe and parts of Asia, and the Arab expansion in the 7th and 8th centuries.

In recent centuries, advances in transportation and globalization have led to increased human mobility, which has further contributed to the mixing and reshaping of human populations. However, the study of ancient DNA and advancements in archaeological techniques continue to reveal new insights into our species’ fascinating migration history.

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