A major question in paleoanthropology—the field dedicated to studying human evolution—asks how humans migrated. Most research suggests that modern humans evolved in Africa, though of course we ended up all over the globe. How did we get there, and what paths did our ancestors take?
New research from a team of scientists led by Andre Luiz Campelo dos Santos from Florida Atlantic University used genomic analysis to determine routes used in human migration. DNA analysis was completed for two individuals who lived about 1,000 years ago in northeast Brazil. This genomic data was then compared with the genomes of modern-day Brazilians living in both the northeast and southeast parts of the country, Panamanians, and Uruguayans.
The archaeological evidence suggests that Indigenous peoples migrated from the north into South America. Based on the new genomic evidence, it is theorized that human migrations along the Atlantic coast eventually would have linked what is now Uruguay and Panama in a 3,270 mile south-to-north migration route. Based on the age of the individuals, this migratory route would have happened around 1,000 years ago. This new research also elucidates how settlements occurred, suggesting that Indigenous people settled along the Atlantic coast in South America after settling the Pacific coast and Andes mountains. Interestingly, and for the first time, there is also evidence for migrations in the opposite direction along the Atlantic coast.
Ancestry was also a key finding in the study, and both Denisovan and Neandertal DNA was identified in the genomes, providing further support for interbreeding between populations. The Denisovan DNA is particularly noteworthy—this DNA was sequenced in 2008 from a finger bone found in the Siberian Denisova Cave in the Altai Mountains in Central and Eastern Asia. This suggests that the admixture between Denisovans and the population who migrated to the Americas must have happened 40,000 years ago, and the Denisovan lineage then persisted allowing genetic signals to appear in South American genomes which are only 1,000 years old.
While much is left to parse in terms of migratory patterns, results from this study provide an important puzzle piece when it comes to understanding the peopling of the Americas.
Sources: Proceedings of the Royal Society B, Archaeology, Labroots, EurkeaAlert, Florida Atlantic University
