The Longest Prehistoric Migration Of Mankind Was 20,000 Km On Foot - And Now We Know Who Took It

This migration was one of the most important journeys ever made by our species.

Homo sapiens are incredible things. During the longest prehistoric migration of mankind, groups of brave people traveled more than 20,000 kilometers (12,427 miles) from North Asia to North America and down to the southernmost tip of South America. In a new study, scientists traced this significant journey using DNA sequence data from 1,537 people from 139 different ethnic groups. The results showed that these first pioneers were essentially Asians in their genetic heritage, as expected, given that they originated in North Asia.

These groups migrated on foot from Siberia through the Bering Land Bridge, a land connection between Asia and North America that existed during the last ice age, and entered America for the first time.

Over the millennia, they split into numerous groups, sneaking into the "new world" and adapting to a wide range of environments, from the dense tropical forests of the Amazon and the arid Chaco deserts to the high peaks of the Andes and the icy plains of Patagonia.

"We found that people who arrived in South America spread to different regions of the continent. We have identified at least four separate groups of ancestors: Andean, Amazonian, Chaco and Patagonian population. These groups were isolated in their own geographical regions, eventually developing unique genetic characteristics," said IFLScience Associate Professor Kim Hee Lim, author of the study from Nanyang University of Technology in Singapore.

"Interestingly, the group that migrated the most to Patagonia - shows the lowest level of genetic diversity," she said.

Looking at the tides and gene flows, the team was able to show that early migrants arrived at the northwestern tip of South America, where modern Panama meets Colombia at least 14,000 years ago.

Although the study did not reveal when people first set foot in America, this timeline coincides with the prevailing view that people were most likely present throughout America at the peak of the last ice age about 26,000-19,000 years ago.

Researchers note that these ideas became possible only because they had a lot of data about Asians. Their work was based on the GenomeAsia100K project, which is the first attempt to map the deep diversity of the Asian population.

"Asian populations are significantly underrepresented in genetic research, despite the fact that they make up most of the world's population and have a high level of genetic diversity. Genetic variants associated with the disease may differ in different populations due to their unique genetic background. When Asians are not included in these studies, they may not fully benefit from the results," Kim explained.

The study also included a lot of data from indigenous groups, which are also underrepresented and equally important for people's history.

"Indigenous populations often have distinctive genetic traits formed by long-term isolation or adaptation to extreme conditions," Kim added.

"Their genomes offer unique windows to the early history of mankind in specific regions. Our current genomes are formed by this evolutionary history - we inherited them from our ancestors. So understanding this past helps us interpret genetic variation today," she said.