Ancient fossil in Brazil genetically similar to modern populations

Luzio, a 10,000-year-old skeleton from São Paulo, Brazil, has some familiar-looking DNA.

He belongs to the same genetic population as all modern-day Indigenous peoples of the Americas, according to new research published in Nature Ecology & Evolution.

Luzio was previously thought to have possibly belonged to a different, older, population, who settled in modern-day Brazil around 14,000 years ago.

“Genetic analysis showed Luzio to be an Amerindian, like the Tupi, Quechua or Cherokee,” says co-author André Menezes Strauss, an archaeologist at the University of São Paulo.

“That doesn’t mean they’re all the same, but from a global perspective, they all derive from a single migratory wave that arrived in the Americas not more than 16,000 years ago.

“If there was another population here 30,000 years ago, it didn’t leave descendants among these groups.” 

The researchers examined the genomes of 34 fossil samples, each at least 10,000 years old, from four different places on the Brazilian coast.

Luzio, among them, is the oldest human fossil found in São Paulo State. He’s named after Luzia, the 13,000-year-old female skeleton which is the oldest known in South America.

Some of the finds came from sambaquis, ancient Brazilian shell mounds.

“After the Andean civilizations, the Atlantic coast sambaqui builders were the human phenomenon with the highest demographic density in pre-colonial South America,” says Strauss.

“They were the ‘kings of the coast’ for thousands and thousands of years. They vanished suddenly about 2,000 years ago.”

The researchers found significant genetic differences between the communities, even thought the archaeological evidence suggested there were cultural similarities.

“Studies of cranial morphology conducted in the 2000s had already pointed to a subtle difference between these communities, and our genetic analysis confirmed it,” says Strauss.

“We discovered that one of the reasons was that these coastal populations weren’t isolated but ‘swapped genes’ with inland communities. Over thousands of years, this process must have contributed to the regional differences between sambaquis.”

The researchers believe that the mysterious disappearance of the sambaqui-builders can be attributed to a change in cultural practices, with fewer shell middens being constructed and more use of pottery.

“This information is compatible with a 2014 study that analyzed pottery shards from sambaquis and found that the pots in question were used to cook not domesticated vegetables but fish. They appropriated technology from the hinterland to process food that was already traditional there,” says Strauss.