A genetic revelation indicates that Luzio, a resident of São Paulo 10,000 years ago, shared Amerindian DNA with contemporary Indigenous populations.
A multi-regional Brazilian investigation that analyzed the genomic data of 34 fossils, including larger skeletons and the coastal mounds of shells and fishbones known as sambaquis, has identified unique variations between communities.
A soon-to-be-published study in Nature Ecology & Evolution discloses that Luzio, the earliest known human skeleton from the state of São Paulo (Brazil), descended from an ancestral group that inhabited the Americas at least 16,000 years ago, leading to the emergence of all modern-day Indigenous peoples, such as the Tupi.
The investigation, which utilizes the broadest collection of Brazilian archeological genomic data to date, also sheds light on the sudden disappearance of the oldest coastal communities responsible for constructing the renowned Brazilian archeological structures known as sambaquis. These enormous shell and fishbone mounds served as homes, burial sites, and territorial markers and are often referred to by archeologists as shell mounds or kitchen middens.
“After the Andean civilizations, the Atlantic coast sambaqui builders were the human phenomenon with the highest demographic density in pre-colonial South America. They were the ‘kings of the coast’ for thousands and thousands of years. They vanished suddenly about 2,000 years ago,” remarked André Menezes Strauss, an archeologist at the University of São Paulo’s Museum of Archeology and Ethnology (MAE-USP) and lead researcher for the study.
Tiago Ferraz is the primary author of the study, which received backing from FAPESP (projects 17/16451-2 and 20/06527-4). The research was executed in collaboration with scholars at the University of Tübingen’s Senckenberg Center for Human Evolution and Paleoenvironment (Germany).
The team scrutinized the genomes of 34 samples from four distinct coastal areas of Brazil. The fossils, originating from sambaquis and other areas across eight sites, were at least 10,000 years old.
The samples included Luzio, the oldest known skeleton from São Paulo, discovered in the Capelinha river midden in the Ribeira de Iguape valley by a group led by Levy Figuti, a professor at MAE-USP. The structure of Luzio’s skull resembles that of Luzia, the oldest human fossil uncovered in South America, which dates back around 13,000 years. Initially, the researchers believed that Luzio might have belonged to a population that differed biologically from modern-day Amerindians, who settled in present-day Brazil approximately 14,000 years ago. However, subsequent analysis proved this hypothesis wrong.
“Genetic analysis showed Luzio to be an Amerindian, like the Tupi, Quechua or Cherokee. 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,” Strauss added.
The genetic information derived from Luzio also answered another query. As river middens differ from coastal ones, Luzio cannot be seen as a direct predecessor of the monumental classical sambaquis that appeared later. This revelation suggests two distinct migration patterns – one into the hinterland and another along the coast.
So, what happened to the sambaqui builders?
The genetic analysis exposed diverse communities with shared cultural practices but considerable biological variations, particularly between the southeastern and southern coastal communities.
“Studies of cranial morphology conducted in the 2000s had already pointed to a subtle difference between these communities, and our genetic analysis confirmed it,” explained Strauss.
They revealed “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.”
Regarding the unexplained disappearance of the coastal civilization, which consisted of the first Holocene hunter-gatherers, DNA analysis distinctly showed that, unlike the European Neolithic population replacements, there was a change in practices in this region, marked by a decrease in shell midden construction and the introduction of pottery by the sambaqui builders. For instance, the genetic material found at Galheta IV (Santa Catarina state), the most iconic site from this era, contained ceramic remains, not shells, which is akin to the traditional sambaquis.
“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,” said Strauss.