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People genetically linked to Clovis culture, one of the oldest continental cultures in North America, have been up to 11,000 years ago. Then they mysteriously disappeared about 9,000 years ago, a new study reveals.
Where did they go? It seems like another group of old people has replaced them, but we do not know how and why that happened, the researchers said.
These results, published online today (November 8th) in the journal Cell, suggest that this population turnover has taken place throughout the South American continent. [In Photos: Human Skeleton Sheds Light on First Americans]
South direction
Previous research suggests that early Americans diverged genetically from their Siberian and East Asian ancestors nearly 25,000 years ago. These people crossed the Bering Strait land bridge and eventually split into distinct populations of North and South America. About 13,000 years ago, members of Clovis culture, renowned for their use of distinctive tools made of sharp stone, swept across North America. According to archaeological excavations, the inhabitants of Monte Verde (Chile) lived in the south of at least 14 500 years ago.
But little was known about how members of Clovis culture were linked to other populations further south.
A 2014 excavation at the rock shelter site of Lapa do Santo, Brazil, where a person about 9,600 years old was discovered.
Credit: André Strauss
To solve the genetic mysteries of these ancient Americans, researchers have contacted indigenous peoples and government agencies throughout Central and South America, seeking permission to study the remains of ancient peoples discovered over the years. .
In total, the international team of scientists was authorized to carry out genome-wide analyzes of 49 ancient peoples whose remains were found in the following countries of Central and South America: Belize, Brazil, Peru, Chile and Argentina. The oldest of these people lived about 11,000 years ago, which is a study that is a major step forward from previous research, which included only genetic data from people under the age of 1,000 years, the researchers said.
Their findings showed that DNA associated with the North American Clovis culture was found in people in Chile, Brazil, and Belize, but only about 11,000 to 9,000 years ago.
"A key finding was that an individual associated with Clovis culture and native to North America, aged about 12,800 years, shares a separate ancestry with the oldest individuals in Chile, Brazil and Belizeans, "co-wrote Cosimo Posth, a postdoctoral researcher in archaeogenetics at the Max Planck Institute for the Science of Human History in Germany, said in a statement. "This supports the hypothesis that the expansion of people who spread Clovis culture in North America has also reached Central America and South America." [In Photos: New Clovis Site in Sonora]
An outside view of Lapa do Santo, Brazil Credit: André Strauss
Curiously, the researchers discovered that the Clovis lineage disappeared around 9,000 years ago. Even today, no DNA associated with Clovis has been found in modern South Americans, the researchers said. This suggests that a continent-wide population replacement took place at that time, said research associate associate David Reich, a professor of genetics at Harvard Medical. School and researcher at the Howard Hughes Medical Institute.
Following this mysterious disappearance, there is a surprising amount of genetic continuity between people who lived 9,000 years ago and those who live today in many parts of South America, the researchers said.
California-Peru Connection
The Cell study also revealed an amazing connection between ancient peoples living in the Channel Islands in California and the Andes of southern Peru at least 4,200 years ago. The researchers discovered that it seems that these two geographically distant groups share the same origins.
The inhabitants of the Channel Islands are unlikely to have traveled to southern Peru, the researchers said. On the contrary, it is possible that the ancestors of these groups gathered thousands of years ago, some found themselves in the Channel Islands and others in South America. But these genes only became common in Peru much later, about 4,200 years ago, when the population may have exploded, the researchers said. [In Photos: 130,000-Year-Old Evidence of Humans in California]
"It may be that this ancestry has arrived in South America thousands of years ago and we just do not have it before," said research associate Nathan Nakatsuka, research assistant at the laboratory. Reich at Harvard Medical School, said in an article the statement. "There is archeological evidence that the population in the central Andes region increased considerably about 5,000 years ago, and the dispersion of particular subgroups during these events may be the reason we detect this ancestry afterwards. "
The individual aged about 11,000 years from the Los Rieles Chilean site was the oldest of the study.
Credit: Bernardita Ladrón de Guevara, 2008
Although these results shed light on the first Americans, they are far from complete. The researchers acknowledged that they did not have human remains over 11,000 years old. "So we could not directly probe the first population movements in Central and South America," they wrote in the study. In addition, although the study covered 49 people between about 11,000 and 3,000 years old, research would be more comprehensive if older people from different regions were included, the researchers said.
"We lacked old data from the Amazon, North of South America and the Caribbean, so we can not determine the relationship between individuals in these areas and those we have analyzed," said Reich in his statement. "Bridging these gaps should be a priority for future work."
Originally posted on Live Science.
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