Migratory Routes to Uruguay: A Story of Indigenous Genomes

February 16, 2023
Science Magazine

Let me introduce you to Native Land Digital, a Canadian non-profit whose digital world map displays the overlap of native lands throughout history. The organization’s mission is to invite non-Indigenous people to consider the importance of land. Their educational resources range from territory acknowledgment documents to an extensive list of native languages. The website also includes many disclaimers and opportunities to provide feedback, suggesting a recognition that its map is not static and therefore subject to change. Mesmerized by the colorful interface and accessible approach to land recognition, I decided to do some exploring.

My curiosity led me to Uruguay. The small southeastern country boasts a present-day population of about 3.5 million people and a cow-to-person ratio of four to one. My own genealogical ancestry connects to this very land, as my mother and her family immigrated from Montevideo (the capital) to the United States in the ’70s. While I am proud of my heritage, I must admit that I knew little about Uruguay’s Indigenous population. In fact, this ignorance dominated throughout the country until the recent rise in population genetic studies and the re-emergence of the Charrúa population — joined by several Indigenous groups — as a formal Indigenous collective.1

Genocide of Indigenous groups in Uruguay began in the 16th century. The 1831 Massacre of Salsipuedes resulted from formal military campaigns by European forces against the Charrúa people.2 However, a recent publication by Emory Assistant Professor of Anthropology John Lindo argues that Charrúa is an oversimplified misnomer.1 Instead, Lindo and his team suggest that the term was used as a sweeping generalization for the remaining Indigenous populations that occupied territory within and around Uruguay’s current borders. In reality, the land was home to a diverse group of distinct populations.1

What would a DNA testing service like 23andMe say about Uruguayan Indigenous genealogical ancestry? In their 2022 publication, Lindo and colleagues use whole genome sequences from two Indigenous individuals dated back to 1,450 and 668 years ago to track migration patterns into Uruguay.1 The data discussed in the paper focuses on the eastern department of Rocha. Their work confirms that “both ancient Uruguay individuals display greater affinity with Indigenous groups from South America than with other populations.”1 More specifically, both individuals were most genetically similar to the Surui and Karitiana groups from the Amazonian region of western Brazil. However, nuance arises from the maximum likelihood tree, which depicts samples from ancient Panama and Uruguay as originating from Sumiduoro5. The Sumiduoro5 archeological site stands in eastern Brazil, far from the aforementioned Amazonian region.1

Above: A maximum likelihood tree and qp Graph highlight ancient Uruguayan connection to deep ancestral events as well as the divergence in Sumiduoro5 into Panama and Uruguay (adapted from Figure 3 in the original publication).

Thus, ancient Uruguay an ancestry can be traced back in two ways: to one early source common to most ancient Indigenous populations in South America and to one event 10,000 years ago pointing towards Sumiduoro5 as the source population of migration to Panama and Uruguay.1

Above: A map reveals that movement north to Panama and south to Uruguay originates in Sumiduoro5, suggesting a migratory route along the Atlantic coast (adapted from Figure 4 in the original publication).

Ultimately, this study offers novel evidence of potential route contributing to the diversity of Indigenous populations in South America. As new research continues to shed light on the genetic makeup of Uruguay’s population, current depictions of ancestry are subject to change. Nonetheless, I’m grateful for the work by Lindo and his colleagues because it sheds light on how Uruguay’s earliest inhabitants made their way to the beautiful rolling plains and coastline that my ancestors called home. 

References:

1 Lindo J, De La Rosa R, Santos A, Sans M, DeGiorgio M, Figueiro G. The genomic prehistory of the Indigenous peoples of Uruguay. PNAS Nexus. May 2022;1(2):pgac047.doi:10.1093/pnasnexus/pgac047

2 Figueira JJ. BBAA Boletín Bibliográfico de Antropología Americana. 1956;19/20(2):118-122.

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