Genes of lost South American peoples point to an unexpected history
Despite its location in the middle of the eastern seaboard of the continent of South America, Uruguay’s brief history is a blur of European conflict, shaped by the colonial interests of the Spanish, British and Portuguese powers.
What is missing are the sounds of prehistory, the voices of indigenous cultures that have called the land’s rolling hills and temperate plains home for thousands of years.
The echoes of that lost past are finally being heard thanks to the efforts of researchers from the University of the Republic of Uruguay, Montevideo, and Emory University and Florida Atlantic University in the US.
His investigation of the remains of two individuals who lived long before Christopher Columbus’ famous trans-Atlantic voyage has revealed surprising connections between populations across the Americas. What’s more, the findings challenge theories that suggest that indigenous peoples of South America are all traced by a single migration.
“This contributes to the idea of South America being a place where multi-regional diversity existed, rather than the monolithic idea of a Native American race in North and South America,” says John Lindow, an Emory University anthropologist.
Both sets of remains were found at a 2,000-year-old archaeological excavation site in Rocha, a coastal city in southeastern Uruguay. One, with two X chromosomes, was estimated to be about 1,400 years old. It was difficult to ascertain the sex of the other but it appears that he lived about 650 years ago.
Although separated over the centuries, the genetics of each contributed to a larger story of a complex ancestry that links indigenous Uruguayans with genomes uncovered from ancient Panama – the land connecting South America with the continent to north and eastern Brazil. The stretch
The findings may also reflect a downward migration path from the north, or later return migration from the south, as genetics move backwards over time.
Surprisingly, the couple’s genome was not closely related to modern-day indigenous Amazonian populations.
The most likely explanation for this pattern is the separation of ancestry among the dissemination of indigenous populations of South America.
“This runs contrary to the principle of single migration that splits at the foot of the Andes,” says Lindo.
It would take too much evidence gathered from a wide range of sources to settle the debate once and for all, a challenge made more difficult by the climate of South America.
Unlike Europe, moist, warm conditions across much of the continent make little work of any of the DNA nestled inside the bones of the dead.
“If you’re of European descent, you can have your DNA sequenced and use that information to pinpoint where your ancestors are from downstairs to specific villages,” Lindo says.
“If you are a descendant of the indigenous people of the Americas, you may be able to know that some part of your genome is Native American, but it is unlikely that you can trace a direct ancestry because there is enough ancient DNA reference. are not available.”
Significantly, the loss and displacement of indigenous populations through genocide and slavery also makes the task of tracing the human story before the European invasion even more challenging.
In the case of Uruguay, the final chapter of an ethnic past closed in 1831, when a diverse group of indigenous peoples, widely recognized as the Charar, died at the hands of the state.
Along the banks of Salsipuedes Creek, dozens lost their lives, while hundreds were taken into slavery.
Uruguay has lacked an ethnic presence since then. While the whispering of DNA hardly compensates for centuries of silence, it is a solid place to learn more about how Uruguay’s indigenous populations fit into a wider picture.
“Through these first whole genome sequences of the indigenous peoples of the region before the arrival of the Europeans, we were able to reconstruct at least a small portion of their genetic prehistory,” says Lindow.
This research was published in PNAS Nexus,
