An international genomic study unveiled the longest documented prehistoric migration in human history, tracing early modern humans' journey from North Asia to the southern tip of South America. This migration, covering more than 20,000 kilometers, was a turning point in human evolution and geographical expansion.
The study is the result of collaboration among 48 researchers from 22 institutions worldwide, including an international research team led by Nanyang Technological University in Singapore. The team analyzed 1,537 genomes extracted from 139 population groups in South America and northeastern Eurasia.
The research team traced the migration path from Africa, through North Asia, to Tierra del Fuego in Argentina, demonstrating that early migrants arrived at the northern limit of South America—near the present-day location of Panama—approximately 14,000 years ago. This feat marks a key milestone in human expansion across the planet, as the first humans rapidly spread across the continent and adapted to diverse habitats.
"The group that migrated to Patagonia has the lowest genetic diversity compared to other regions, which can be explained by long-distance migration and isolation," said Associate Professor Dr. Kim Hie Lim of Nanyang Technological University, who led the research, according to Hankyoreh.
Over time, these groups spread to different geographical regions and genetically diverged—a divergence that can still be observed in the genetic traces of today's indigenous communities in the Andes, Amazon, Chaco, and Patagonia regions. The study revealed that these early pioneers were essentially Asian in their genetic heritage, as expected considering they originated in North Asia.
Analyses with whole genome sequencing revealed that the greatest human genetic diversity is found in Asia, not in Europe as previously assumed, challenging a persistent misconception. "Our work shows that Asian populations harbor a genetic diversity richer than previously thought, far exceeding that of European populations," said Professor Stephan Schuster, one of the lead authors, as reported by SciencePost. Schuster also pointed out that "Asian populations are significantly underrepresented in genetic research, even though they make up a large portion of the world's population and have a high level of genetic diversity."
Over thousands of years, these groups splintered into numerous populations as they migrated into the Americas, eventually reaching the southernmost points of South America. The study showed that South American migrants split into four groups, forming the core ancestry of modern South Americans. One group moved through the valleys of the Andes Mountains, the highest mountain range outside of Asia; another group remained in the Amazon Basin; a third group advanced to the southern Patagonia ice fields; and the fourth group moved to the eastern Dry Chaco region.
"We found that the people who arrived in South America spread across different regions of the continent. We identified at least four distinct ancestral groups: the Andean, Amazon, Chaco, and Patagonian populations. These groups became isolated in their own geographic regions, developing unique genetic characteristics over time," explained Associate Professor Kim.
The research team noted that these ancient populations faced extremely diverse and often hostile environments, including tropical forests, mountains, deserts, and glacial areas. "Our results highlight the extraordinary ingenuity of the early indigenous groups who colonized these varied environments," said Elena Gusareva, as reported by SciencePost.
Moreover, the study found that the successive migrants carried only a restricted subset of the original genetic diversity. This reduction in genetic diversity in indigenous populations, especially in genes associated with the immune system, may have reduced their capacity to combat certain diseases. "The decrease in genetic diversity led to a decrease in the diversity of immune-related genes. This may explain why the indigenous communities in this region were more vulnerable to the diseases brought by European colonizers," added Kim, according to Hankyoreh.
The study underscores the need to integrate more genetic data from Asian populations to refine diagnostics, treatments, and medical strategies adapted to human diversity. "The bias in genomic studies has left many Asian and Native American populations underrepresented in science," emphasized Schuster.
Produced with the assistance of a news-analysis system.