Colombia sits on the land through which Homo sapiens first spread from Central America to South America more than 14,500 years ago, making it a crucial population gateway. Researchers have now found evidence of a previously unknown people who once lived there.
Specifically, an international team has traced back 6,000 years of history, based on DNA analysis of 21 sets of carefully chosen human remains. The remains were collected from five sites across the Altiplano plateau, in central Colombia.
These DNA records reveal a fascinating timeline, including the existence of an ancient population with genetics unrelated to any modern descendants – a group of people who may have been some of the earliest settlers in South America, but who subsequently disappeared completely.
“We couldn’t find descendants of these early hunter-gatherers of the Colombian high plains – the genes were not passed on,” says anthropologist Kim-Louise Krettek, from the University of Tübingen, in Germany.
“That means in the area around Bogotá there was a complete exchange of the population.”
DNA contains the genetic instructions we need to grow into the people we are, with contributions from parents, grandparents, and generations before them. By studying it, scientists can work out links between generations – and see how these generations moved and evolved over time.
While one group was settled in the Colombian region around 6,000 years ago, a different community, with completely separate genetics, called the area home starting about 2,000 years ago. These people, who would’ve most likely spoken Chibchan languages, do have known genetic links to modern groups from the lower part of Central America.
This later group also represents a cultural shift, from the hunter-gatherers of the original population, to people who were skilled in pottery-making and more sophisticated types of agriculture. It seems that these people stayed in place until settlers from Europe started arriving in the 16th century.
“That genetic traces of the original population disappear completely is unusual, especially in South America,” says geneticist Andrea Casas-Vargas, from the National University of Colombia.
What happened to this newly discovered group, established 6,000 years ago, is something the researchers don’t speculate on – though the usual causes of conflict or disease may be responsible. It’s something future studies could look into.
Even with many questions remaining unanswered though, the research offers some valuable insight into the history of South America and some of the earliest people to venture down from the north.
Earlier studies have suggested that the story of indigenous people in the region may be more complex than previously thought, and genetic links to South America have connected its people to places as far away as Australia.
With Colombia sitting right on the land bridge between South America and the continent to the north of it, however, it’s a particularly important place to study – and it likely has more secrets to give up yet.
“These are the first ancient human genomes from Colombia ever to be published,” says anthropologist Cosimo Posth, from the University of Tübingen.
The research has been published in Science Advances.
