Colombia forms the gateway to South America. From here, the first people spread across the entire continent. But her descent story still harbors secrets today. Now researchers have analyzed the fossil genetic material from 21 people who lived on the Colombian plateau up to 6000 years ago. In doing so, they found references to a population of formerly hunters and collectors, whose genome differs from the all other historical peoples in South America. The traces of this population disappeared around 2000 years ago. Apparently, the region’s population changed completely, probably through a second wave of settlement from Central America.
The first people who populated the American double continent came from hunters and collectors who lived in Siberia and East Asia around 20,000 years ago. They came to America via Beringstrasse and quickly spread south. They entered South America for the first time in the area of today’s Colombia. From there, several descent lines lead into the different parts of South America. Some of them have been preserved in the genetic makeup of the indigenous population of the continent.
Isolated branch branch
Now a team led by Kim-Louise Krettek from the University of Tübingen has found genetic references to a previously unknown population of formerly hunters and collectors who lived at the plateau around Bogotá in Colombia about 6000 years ago. The researchers examined the genetic material from 21 individuals from five archaeological excavation sites, which cover a period of around 4,000 BC until shortly before the start of Spanish colonization around 500 years ago.
The seven oldest human remains come from the excavation site Checua, which is located north of Bogotá at an altitude of around 3,000 meters. “Our results show that the Checua individuals descend from the earliest population that has spread and differentiated through South America within a very short time,” reports Krettek. But apparently this branch was later isolated genetically and disappeared without leaving traces in the genomes of later people. “We were unable to follow these early hunters and collectors of the Colombian plateau – the genetic material was not passed on,” says Krettek.
Change of the population
Accordingly, the area around Bogotá could have been completely changed by the population long before the Europeans arrived. Individuals who lived in the same region after this change 2000 years ago probably came from a second wave of settlement from Central America. “In addition to technological developments, such as ceramics, the people of this second migration movement probably also brought Chibcha languages to today’s Colombia,” explains co-author Andrea Casas-Vargas from the National University of Colombia in Bogotá. “Damblers of this language family are still spoken in Central America today.”
So far, science had assumed that the population of South America, despite great cultural changes over many thousands of years, remained genetically constant and developed within the continent. Therefore, according to the researchers, it is unusual that the genetic traces of an original population have disappeared completely there.
Since the new knowledge potentially touches a sensitive area of the self-image and identity of the indigenous population of South America, the research team has also exchanged information in the High level of Bogotá as part of its work. “We emphasized that the genetic knowledge cannot be equated with concepts of cultural identity,” report the researchers. “As a scientist who deals with questions that are important for indigenous communities in Colombia, we respect and appreciate the wealth of community -based knowledge.”
Source: Kim-Louise Krettek (University of Tübingen) et al., Science Advances, Doi: 10.1126/sciadv.ads6284
