have found skeletons that could rewrite human history. The remains, which are 6,000 years old, belonged to a mysterious group of people and were recently uncovered at the ancient site of Checua, near Bogotá, in .

The skeletons were of hunter-gatherers whose DNA does not match that of any population in the region today. Their DNA shows a distinct link with the earliest humans to reach . The group remained genetically isolated for thousands of years before their lineage disappeared completely.

The archaeologists analysed DNA, extracted from bones and teeth, from 21 people. They lived between 6,000 and 500 years ago but their DNA samples carried a unique ancestral signature that has completey vanished in modern times.

Kim-Louise Krettek, lead author and a Ph.D. student at the Senckenberg Center for Human Evolution in Germany, said: "This area is key to understanding how the Americas were populated. It was the land bridge between North and South America and the meeting point of three major cultural regions: Mesoamerica, Amazonia, and the Andes."

The early people had no genetic relation to other ancient groups in South America. They also didn't share ancestry with early North America populations.

According to the , Kim-Louise Krettek added: "Our results show that the Checua individuals derive from the earliest population that spread and differentiated across South America very rapidly.

"We couldn't find descendants of these early hunter-gatherers of the Colombian high plains, the genes were not passed on. That means in the area around Bogotá there was a complete exchange of the population."

The genetic landscape of the Bogotá highlands changed around 2,000 years ago as the earliest Checua were replaced by a new population. Genetic evidence shows the new culture arrived with migrants from Central America.

The migrants likely introduced technological advances and languages to what is now Colombia. Andrea Casas-Vargas, co-author and researcher at Universidad Nacional de Colombia, said: "Branches of this language family are still spoken in Central America today."

She added: "Up to now, strong genetic continuity has been observed in the population of the Andes and the southern cone of South America over long time periods and cultural changes."