A new study recently published in the American journal Cell Reports shows that through the study of mitochondrial DNA (deoxyribonucleic acid) samples, researchers have identified two migration events that occurred during the Ice Age. Early populations from the northern coast migrated along the Pacific coast to the Americas. This adds new clues to understanding the ancestral origins of Native Americans.
Previous studies have shown that the ancestors of Native Americans originated in Asia, most likely from eastern Asia , and they reached the Americas through the then Bering Land Bridge and the Inland Ice-Free Corridor. But recent genetic, geological and archaeological evidence suggests that populations migrated to the Americas from various parts of Eurasia.
Li Yuchun, the first author of the study and an associate researcher at the Kunming Institute of Zoology, Chinese Academy of Sciences, said: "In addition to the previously described ancestral sources of Siberia, Australia-Melanesia and Southeast Asia, we found that the populations in the northern coastal areas of China also had a strong influence on the origin of Native Americans. The gene pool contributes. ”
Researchers from Kunming Institute of Zoology, Chinese Academy of Sciences and other institutions searched more than 100,000 modern human DNA samples and more than 15,000 ancient human DNA samples from Eurasia. Using mitochondrial DNA tracking methods, they finally identified 216 modern human and The mitochondrial DNA of 39 ancient people belonged to an ancient genetic lineage. This lineage may confirm the link between Paleolithic East Asian populations and earlier populations in places like Chile, Peru and California, USA.
By comparing the samples' accumulated genetic mutations, geographic location, and dating by radiocarbon techniques, the researchers were able to trace the branching paths of this lineage, identifying two migration events from what is today the northern coast of China to the Americas. The researchers believe that the first migration occurred during the last glacial maximum from 26,000 to 19,500 years ago, when the ice sheet covered the largest area and the conditions in northern China may not be suitable for human habitation. The second deglaciation occurred between 19,000 and 11,500 years ago. It may be due to the improvement of climate conditions that the population increased rapidly, which promoted the migration of the population in this area to other areas.
The discovery sheds new light on the mystery of the origins of Native Americans. The next step, the researchers say, is to collect and investigate more genetic lineages from Eurasia to find more clues to the mystery.