An international team of researchers uncovered evidence of an unknown ancient human population in Colombia dating back 6,000 years, according to a new study published in the journal Science Advances. The study revealed that a group of hunter-gatherers settled in the Altiplano plateau of central Colombia around 6,000 years ago, but their genetic lineage has no connection to modern humans, indicating their complete disappearance.
"These are the first ancient human genomes from Colombia that are published," said Professor Cosimo Posth, emphasizing the study's relevance for understanding the initial routes that populated South America, according to AZERTAC.
The researchers sequenced, for the first time, the DNA of ancient inhabitants of the region. Geneticist Andrea Casas-Vargas from the National University of Colombia noted the mystery of the total disappearance of the genetic lineage of the first hunter-gatherers. "That genetic traces of the original population disappear completely is unusual, especially in South America," she said.
The researchers analyzed DNA from 21 human remains, approximately 6,000 years old, discovered during excavations at five archaeological sites in the Checua region of the Altiplano plateau in central Colombia, located north of Bogotá at about 3,000 meters altitude.
About 2,000 years ago, a different group arrived in the region after the ancient hunter-gatherers had become extinct. This group demonstrated cultural evolution with improved agricultural and pottery skills.
"In addition to technological developments like pottery, it is likely that the inhabitants of this second migration also brought the Chibchan languages to what is now Colombia," explained Casas-Vargas. These contributions are part of the cultural legacy that gave rise to historical communities such as the Muiscas.
The researchers do not provide a precise answer as to why and how the initial population from 6,000 years ago disappeared, but they are continuing their study to determine the reasons. Factors such as disease or social conflict are suspected to be potential causes.
"We have not found any descendants in later individuals from the Bogotá region," stated Kim-Louise Krettek, an anthropologist from the University of Tübingen, indicating the complete disappearance of the genetic material of these first settlers. Among the more recent remains studied, approximately 2,000 years old, no trace of the initial population is detected, underscoring the rarity of this phenomenon.
The samples were extracted from bones and teeth and span a temporal interval of nearly 6,000 years, culminating just before the arrival of the Spanish conquerors. The oldest samples were obtained from Checua, where the remains date back to around 4,000 BCE, coinciding with the expansion of hunter-gatherer groups from the north to the south of the continent.