The Roots of the Mapuche

Chiloé is a fertile island in the Pacific, not far from mainland Chile. It is part of the ancestral homelands of the Mapuche, Chile's largest indigenous ethnic group. For centuries they fought off both Spanish colonizers and the Incas. Only a minority now live in their ancient places of origin. Most have moved close to the sprawling Chilean capital of Santiago. Known as the country’s kitchen garden, on Chiloé population geneticist Chiara Barbieri and her team embarked on a study to explore the genetic heritage of the Mapuche. 

“We wanted to know more about the genetic context of their history before Europeans arrived,” she explains. At the same time, the study was intended to highlight the importance of this indigenous group, which like many first nations was displaced by European settlers. “Our work also honors these marginalized groups and aims to give them a stronger identity,” adds PhD student and lead author Epifania Arango. Recently published, the study of the Mapuche has more than achieved both of these goals. It offers evidence of an extraordinarily long history of the group’s settlement of the south of South America. It goes back millennia: “We were able to show that the Mapuche’s ancestors came to the area of central Chile and Chiloé over 5,000 years ago,” says Barbieri.

The long-term investigation drew in part on paleogenetic testing, in other words the analysis of genetic material from fossils found in North and South America, as well as other regions. This was already held in databases. In the other part of the study, saliva samples were provided by 64 members of the Mapuche from the island of Chiloé and the area of Araucanía on the neighboring mainland. By comparing the genetic patterns of their DNA, researchers were able to reconstruct lineages and family relationships. 

Genetic analyses like these are not without their problems. In the past, researchers have repeatedly abused indigenous ethnic groups as mere study subjects, and have used their findings for other purposes without consulting with the people themselves. “We were mindful of inclusivity right from the start,” Barbieri emphasizes. Working with researchers from Chile, an anthropologist and a linguist, she first contacted the Mapuche in 2019 to explain the context of the project and the importance of genetic data. “We invested a lot of time in motivating people to take part,” Barbieri continues. “We were very delicate in our approach and didn't put any pressure at all on anyone.” Even though they fundamentally supported the project’s aims, there were repeated cases in which people did not want to take part because they were suspicious of the genetic aspect.

The 64 saliva samples ultimately provided a foundation from which to untangle the lineage and relationships of the Mapuche in the South American context. The researchers were able to use the resulting DNA sequence data to both zoom in on the far distant past and form a picture of more recent history.

Genetic analyses stretch back to the Middle Holocene period around 7,000 to 8,000 years ago. Around this time, migration from the north resulted in the formation of three major groups in South America. They settled in the Andes, the Amazon basin and the Southern Cone (see box). The southern group divided into three further lines, one of which took ownership of central Chile and the archipelago around Chiloé. What these people called themselves and how they lived is not known, but the genetics show that they are closely related to the Mapuche. “Based on our studies, we concluded that the direct genetic ancestors of the Mapuche were living on Chiloé and in central Chile at least 5,000 years ago,” Epifania Arango says. At the same time, the Mapuche from central Chile regularly migrated southwards towards the Tierra del Fuego, and had exchanges with groups such as the Kawéskar, who settled Patagonia. However, for a long period they distanced themselves from the peoples living further north, in the Andes. The genetic data suggests that the Mapuche lived in “relative isolation” for four millennia, until approximately 1,000 years ago. 

Links to the Andean populations emerge if zoom out and focus on the more recent past, some 500 to 1,000 years ago. That is when the Mapuche were evidently seeking contact with their neighbors to the north. “We find genetic exchange, but most of all cultural relationships,” says Chiara Barbieri. Plants such as potatoes, quinoa and maize were traded, for example. The linguist participating in the study also documented the transfer of special words from Quechua, spoken in the Andes, to the Mapudungun language of the Mapuche. The latter is classified as a language isolate, meaning that it cannot be assigned to any known linguistic group. This is in keeping with the millennia-long genetic isolation of the Mapuche in southern South America. 

There was contact with the Andean Highlands before the Incan conquests of the 15th century. Coming from the north, the Incas tried in vain to subjugate the Mapuche. They were forced to turn back, just like the Spanish, who also faced fierce resistance. The colonizers recognized the Mapuche as an independent ethnic group in 1641. An independent Chile confirmed this status in 1825. It was not until the mid-19th century that large sections of Mapuche territory were incorporated into the Chilean state and distributed to European settlers. 

With this bitter experience in mind, the researchers’ caution is understandable. They wanted “peer-to-peer contact without any neocolonialist attitudes,” as Epifania Arango puts it. The research team undertook to “give the results back” by sharing their findings with the participants and the local population before they were published in scientific journals. Arango prepared information materials in which she described the basics of genetics and DNA analyses, and the study’s key conclusions, in simple Spanish. 

The COVID-19 pandemic delayed the project, and the findings were not communicated until the spring of 2022, at a total of 16 meetings. “Explaining complex genetics to lay people is quite the challenge,” says Arango. However, she is sure that at least those who took part in these workshops understood their primary messages. The Mapuche took the findings on board with both pride and humility, she notes. 

Yet not even the researchers could answer the question that most interested people, specifically: how indigenous am I? Am I 100% Mapuche? The scientists then had to explain that, from the genetic perspective, there are only minimal differences between all human beings. More precisely, they are found in less than one ten-thousandth of the entire human genome. According to Arango, “genetics offers no answers as to identity.” What it can do, however, is strengthen the community spirit of a marginalized group.