The history of the people of America has just been re-interpreted. The largest and most comprehensive study ever conducted on the basis of fossil DNA extracted from ancient human remains found on the continent has confirmed the existence of a single ancestral population for all American ethnic groups, past and present.
Over 17,000 years ago, this original contingent crossed the Bering Strait from Siberia to Alaska and began to take on a new world. Fossil DNA shows an affinity between this migration stream and the populations of Siberia and northern China. Unlike traditional theory, she had no relationship to Africa or Australasia.
A new study also reveals that once they settled in North America, the descendants of this ancestral migration stream diversified to two rows 16,000 years ago.
The members of one line crossed the Isthmus of Panama and drew South America with three successive waves.
The first wave occurred between 15,000 and 11,000 years ago. The second took place 9,000 years ago. There are fossil DNA records from both migrations throughout South America. The third wave is much more recent, but its effect is limited, as it was 4200 years ago. Its members settled in the central Andes.
The article about the study was just published in the journal Cell a group of 72 researchers from eight countries affiliated with the University of Sao Paulo (USP) in Brazil, Harvard University in the United States and the Max Planck Institute for Science of Human History in Germany.
According to scientists, the family who made the north-south route between 16,000 and 15,000 years belonged to the Clovis culture, which was named for a group of archaeological sites dug in the United States 13,500-11,000 years ago.
Clovis' culture has been named to have silicon tips in the Clovis Hill in New Mexico in the 1930s. Clovis sites have been identified throughout the United States and in Mexico and Central America. In North America, Clovis pursued pleistocene megafaunas, such as giant laziness and mammoth. With the decline of megafauna and its extinction 11,000 years ago, Clovis culture disappeared. Long before, however, a group of hunters-collectors traveled south to explore new hunting grounds. They eventually settled in Central America, as evidenced by the 9,400-year-old human fossil DNA found in Belize and analyzed in a new study.
At a later time, probably following a herd of mastodones, hunters and clovi hunters crossed the Istambus of Panama and spread to South America, as evidenced by genetic records from burial sites in Brazil and Chile. This genetic proof is confirmed by well-known archaeological findings, such as the Monte Verde site in southern Chile where humans killed 14.7 million mastodons.
Among the many famous Clovis sites is the only cemetery associated with the Clovis tools in Montana, where the remains of the boy (Anzick-1) were found 12,600 years ago. DNA extracted from these bones is linked to DNA from the skeletons of people who lived 10,000 and 9,000 years ago in caves at Lagoa Santa, the state of Minas Gerais in Brazil. In other words, the people of Lagoa Santa were partial descendants of migrants Clovis from North America.
"From the genetic point of view, the Lagoa Santa people come from the first American Indians," said archaeologist André Menezes Strauss, who co-ordinated the Brazilian part of the study. Strauss is associated with the Museum of Archeology and Ethnology of the University of Sao Paulo (MAE-USP).
"Surprisingly, members of this first line of South Americans did not have any identifiable descendants among today's Amerindians," he said. "About 9000 years ago, their DNA completely disappears from fossil specimens, replacing DNA from the first migration wave before Clovis culture." All living Amerindians are descendants of this first wave. people of Lagoa Santa disappeared. "
One possible reason for the disappearance of DNA from the second migration is that it has been diluted in the DNA of the Amerindians who are descendants of the first wave and can not be identified by existing methods of genetic analysis.
According to Tábita Hünemeier, Genetics at the Institute of Bioscience of the University of Sao Paulo (IB-USP) who was involved in the research, "one of the main results of the study was the identification of Luzia people as genetically related to the Clovis culture that decomposes the idea of two biological components, that there are two migrations in America, one with African characters and another with Asian features. "
"The Lusian people had to be the result of a migratory wave coming from Beringia," she said, referring to the now submerged Bering Bridge, which, when glaciers, merged with Siberia in Alaska when sea levels were lower.
"Molecular data suggests that South America was replacing the population 9,000 years ago. Luzia people have disappeared and replaced by Americans today, although both have a common origin in Beringia," Hünemeier said.
The contribution of Brazilian scientists to the study was crucial. Among the 49 people from whom fossil DNA was derived, there were seven skeletons dated 10,100 to 9,100 years ago, from Lap to Santo, a rock shelter in Lagoa Santa.
Seven skeletons, alongside dozens of others, were found and exhumed in subsequent archaeological campaigns at the site originally headed by Walter Alves Neves, a physical anthropologist at IB-USP and by Strauss in 2011. Archaeological campaigns led by Neves in 2002-2008 were funded by the São Paulo Research Foundation – FAPESP.
A whole new study looked at fossil DNA from 49 individuals found in 15 archeological sites in Argentina (two sites, 11 individuals dated 8,900 to 6,600 years ago), Belize (one place, three individuals dated 9,400 to 7,300 years ago) Brazil of individuals dated 10,100 to 1,000 years ago), Chile (three sites, five individuals dated 11,100 to 540 years ago) and Peru (seven sites, 15 people over 10,100-730 years old).
The Brazilian skeletons come from the Lapa do Santo archaeological site (seven people about 9600 years ago), Jabuticabeira II in the state of Santa Catarina (sambaqui or shell with five people dated about 2000 years ago) as well as the two Middens in the Ribeira Valley, São Paulo State: Laranjal (two individuals dated about 6700 years ago) and Moraes (one person dated about 5800 years ago).
Paulo Antônio Dantas de Blasis, an archaeologist affiliated with the MAE-USP, led a kick at Jabuticabeira II, which was also supported by FAPESP through a thematic project.
Excavations at the river basin of São Paulo led Levy Figuti, also a MAE-USP archaeologist, and was also supported by FAPESP.
"Moraes' skeleton (5800 years old) and Laranjal skeleton (6,700 years) are among the oldest in the south and southeast of Brazil," Figuti said. "These sites are strategically unique because they are located between the highlands on the Atlantic Plateau and the coastal plain, and they make a significant contribution to understanding how Brazil's south-eastern side has been populated."
These skeletons were found between 2000 and 2005. They originally represented a complex combination of coastal and inland cultural features, and the results of their analysis varied widely, except when one skeleton was diagnosed as Paleo-Indian (DNA analysis is not complete).
"The study that has just been published represents a significant step forward in archaeological research and exponentially enhances what we knew only a few years ago about the archaeogenesis of the population of America," Figuti said.
Hünemeier has recently made a major contribution to the reconstruction of human history in South America using paleogenomics.
Not all human remains found in the oldest archaeological sites in Central and South America belonged to the genetic descendants of Clovis culture. The inhabitants of several locations did not have DNA associated with Clovis.
"This shows that alongside the genetic benefit, the second migration wave to South America that was associated with Clovis could also bring technological principles that would be expressed in famous places found in many parts of South America," said Strauss.
How many human migrations from Asia came to America at the end of the Ice Age more than 16,000 years ago were unknown. The traditional theory, formulated in the 1980s by Nevis and other scientists, consisted in the fact that the first wave had African features or features similar to those of Australian natives.
In accordance with this theory, a well-known forensic reconstruction of the face of Luzia was carried out. Luzia is the name of the fossil skull of a woman who lived in the Lagoa Santa region 12,500 years ago and is sometimes referred to as "the first Brazilian".
The Busta Luzie with African features was based on skull morphology by British anatomical artist Richard Neave in the 1990s.
"The shape of the skull, however, is not a reliable marker of origin or geographical origin." Genetics is the best basis for this type of conclusion, "Strauss explained.
"The genetic results of the new study clearly show that there is no significant link between the people of Lagoa Santa and groups from Africa or Australia, so the hypothesis that Luzia people come from the migratory wave before the ancients of today's Amerindians has been refuted. they were completely American. "
The new bust replaced Luzia in the Brazilian scientific pantheon. Caroline Wilkinson, a forensic anthropologist at Liverpool John Moores University in the UK and a disciple of Neave, has reconstructed the face of one of the people exiled in Lapa to Santo. The reconstruction was based on a retroformed digital skull model.
"Using the traditional facial reconstruction of Luzia with strong African features, this new facial reconstruction reflects the physiognomy of the first inhabitants of Brazil more accurately, showing the general and unclear features that have been the foundation of great American-Indian variety for thousands of years," Strauss said.
Study published in 2006 Cell, he added, also features the first genetic data on the Brazilian coastal sambaquis.
"These monumental shells were built about 2,000 years ago by folk companies living on the Brazilian coast.The analysis of fossil DNA from funerary shells in Santa Catarina and São Paulo shows that these groups were genetically related to the Amerindians living in southern Brazil today, "he said.
According to Strauss, DNA extraction from fossil wood is technically very demanding, especially if the material was found in a tropical climate site. For nearly two decades, extreme fragmentation and significant contamination have prevented various research groups from successfully selecting genetic material from the bones found in Lagoa Santa.
This was done through the methodological advancement developed by the Max Planck Institute. As Strauss explained excitedly, much more must be found.
"The construction of the first archeogenetic laboratory in Brazil should be launched in 2019 through a partnership between the University of Sao Paulo Museum of Archeology and Ethnology and its FAPESP Biological Institute IB, giving new direction to the research of people from South America and Brazil," Strauss said.
"This study, to a certain extent, changes not only what we know about how this region has been filled but also significantly changes how we study human skeletal remains," Figuti said.
Human remains were first found in Lagoa Santa in 1844, when the Danish naturalist Peter Wilhelm Lund (1801-1880) discovered about 30 skeletons deep in a flooded cave. Almost all of these fossils are now in Copenhagen's natural heritage site. One skull stayed in Brazil. Lund gave it to the Brazilian Institute of History and Geography in Rio de Janeiro.
Colonization of jumps and borders
On the same day as Cell The article was published (November 8, 2018), an article in the journal Science also introduced new findings on fossil DNA from the first migrants to America. André Strauss is one of the authors.
Among the fifteen-year-old skeletons from which the genetic material was removed, five belong to the Lund's collection in Copenhagen. They date between 10,400 and 9,800 years ago. It is the oldest in sampling, along with a Nevadian person estimated at 10,700 years.
The sample contained fossilized human remains from Alaska, Canada, Brazil, Chile and Argentina. The results of its molecular analysis suggested that people from the first Alaska human groups that were born in America did not just progressively occupy the territory in parallel with population growth.
According to research investigators, molecular data suggests that the first people who invaded Alaska or neighboring Yukon split into two groups. It happened between 17,500 and 14,600 years ago. One group colonized North and Central America, the other South America.
America's populations followed leaps and bounds, as small trails of hunters and collectors traveled far and wide to settle in new areas until they reached the Tierra del Fuego in a movement lasting one or two millennia.
Among the 15 individuals whose DNA was analyzed, it was found that three of the Lagoa Santa Five had some genetic material from Australasia, as suggested by Nevis's theory of occupation in South America. Scientists are unable to explain the origin of this Australasian DNA or how it ended in just a few Lagoa Santa people.
"The fact that the genomic signature of Australasia is present in Brazil for 10,400 years, but it is missing in all the genomes that have been tested or older and are located in the north is a challenge because of its presence in Lagoa Santa," they said.
Other fossils collected during the twentieth century include the Luzia skull, found in the 1970s. Nearly 100 skulls dug by Neves and Strauss over the past 15 years are now taking place at the USP. A similar number of fossils is held at the Pontifical Catholic University of Minas Gerais (PUC-MG).
But the vast majority of these osteological and archaeological treasures, more than 100, were deposited at the National Museum in Rio de Janeiro and were probably destroyed in a fire that destroyed this historic building on September 2, 2018.
Skull Luzia was exhibited at the National Museum next to Neave's facial reconstruction. Scientists were afraid they were lost from the fire, but fortunately it was one of the first objects to be taken from the ruins. He collapsed, but survived. The fire destroyed the original reconstruction of the face (of which there are several copies).