Luzio is the oldest human skeleton found in the state of São Paulo, in Brazil. It was found in the sambaqui (shell deposit) of the Capelinha river, in the Ribeira de Iguape valley. Surprisingly, their DNA is virtually indistinguishable from that of today's indigenous peoples.
Researchers from the University of Sao Paulo and the German University of Tübingen have reanalyzed these remains and the genomes of 34 other individuals who lived more than 10,000 years ago and who were buried in four different areas of the Brazilian coast.
Their results, explained in an article published in the journal Nature Ecology
“After the Andean civilizations, the sambaqui builders of the Atlantic coast were the most densely populated human phenomenon in pre-colonial South America. They were the 'kings of the coast' for thousands and thousands of years. But they suddenly disappeared about 2,000 years ago," says André Menezes Strauss, lead author of the study.
Their analysis provides an explanation for the disappearance of these ancient coastal communities that built the icons of Brazilian archeology known as sambaquis, huge mounds of shells and fish bones used as homes, cemeteries and territorial boundaries.
Investigators often refer to these monuments as mounds of shells or kitchen baskets. The archeologists have analyzed the remains from up to eight from these sites: Cabeçuda, Capelinha, Cubatão, Limão, Vau Una, Jabuticabeira II, Palmeiras Xingu and Pedra do Alexandre.
The morphology of Luzio's skull is similar to that of Luzia, the oldest human fossil found to date in South America, dating to about 13,000 years ago. Experts thought it might have belonged to a biologically different population than modern-day Amerindians, who settled in what is now Brazil around 14,000 years ago, but it turns out they were wrong.
“The genetic analysis showed that Luzio was Amerindian, like the Tupi, the Quechua or the Cherokee. That's not to say they're all the same, but from a global perspective, they all derive from a single migratory wave that reached the Americas no more than 16,000 years ago. If there was another population here 30,000 years ago, it left no descendants among these groups," Strauss said.
Luzio's DNA also answered another question. River middens are different from coastal ones, so the find cannot be considered a direct ancestor of the great classic sambaquis that appeared later. This discovery suggests that there were two distinct migrations: inland and along the coast.
Genetic analysis revealed the existence of communities with cultural similarities but significant biological differences, especially between the southeastern and southern coastal groups. “Studies of cranial morphology carried out in the 2000s already pointed out a subtle difference, and our analysis confirmed it”, points out the researcher.
“We found that one of the reasons was that these coastal populations were not isolated but 'exchanging genes' with inland communities. Over thousands of years, this process must have contributed to regional differences among the sambaquis,” he added.
As for the mysterious disappearance of this coastal civilization, made up of the first Holocene hunter-gatherers, the analysis of the DNA samples clearly showed that, in contrast to the European Neolithic replacement of entire populations, what happened in this part of the world was a change of practices.
While the construction of shell deposits began to decline, the introduction of ceramics by sambaqui builders increased. For example, the genetic material found in Galheta IV (Santa Catarina state), the most emblematic site of the time, does not have remains of shells but of ceramics, although it is similar to classic sambaquis.
“The pots in question were no longer used to cook domesticated vegetables but fish. They appropriated technology from the interior to process foods that were already traditional on the coast”, concludes Strauss.
