Thread by @AntiquityJ

🆕: Archaeologists have recovered >400-year-old DNA from colonial-era burials in Mexico, revealing the diversity of early European settlements in the Americas.

An #AntiquityThread (paper: buff.ly/3yYgdgN) 1/12 🧵

Campeche was an early colonial settlement in Yucatán. It was founded in 1540, less than 20 years after the Spanish conquest of the Aztecs, once conquistadors secured their rule. 2/12

📷: Location of Campeche

The city was served by a parish church until it was replaced by a cathedral in 1680. The church was rediscovered in 2000 during rescue excavations when 129 early colonial burials were found. 3/12

📷: Campeche’s cathedral, on the colonial plaza where the early church stood

Early attempts to extract DNA from these burials failed. Now advances in aDNA research have allowed Professor Vera Tiesler and a team of researchers from @Harvard to gather genetic data from this important site. 4/12

📷: Rescue excavations of the cemetery

“Ancient DNA methods have improved to the point where we can generate robust data from warm, humid environments,” said Dr Jakob Sedig, from the Reich Laboratory at Harvard University and co-lead author. This is encouraging for future ancient DNA analysis in this region. 5/12

aDNA was gathered from 10 people. Most were local Indigenous Americans, but there were also people of European and sub-Saharan African ancestry. Notably, this contradicted some previous attempts to identify sex & ancestry from physical attributes. 6/12

📷: PCA of the aDNA

“Early colonial Campeche had a multi-ethnic population, where previously disparate groups mixed for the first time,” said co-lead author Prof. Tiesler, from @uady_mx, “The Campeche cemetery confirms the prompt forced integration of all populations into this new way of life.” 7/12

Despite these diverse populations living (and being buried) together, there was no evidence people from these different backgrounds had children together. None of the individuals had recent ancestry from any other populations. 8/12

📷: Plan of the cemetery

“We expected to find individuals with mixed genetic ancestry. However, our analysis found no evidence of this,” said Dr Sedig, “This seems to indicate that although they were buried together, different groups maintained some degree of separation in life.” 9/12

Many of these details uncovered from the palaeogenetic data are missing from historical records, as they are mostly focused on the inhabitants of European ancestry. 10/12

📷: Panel from the History of the Indies of New Spain

“These data add a new ‘human’ layer to our understanding of a crucial era and location in the history of New Spain,” said Professor Tiesler, “These results provide insights into the individual lives and social divides of the town’s founder communities.” 11/12

If you want to find out more, the original research is 🆓:

'Life and death in early colonial Campeche: new insights from ancient DNA' - Vera Tiesler, Jakob Sedig, Nathan Nakatsuka, Swapan Mallick, Iosif Lazaridis, Rebecca Bernardos et al.
doi.org/10.15184/aqy.2…
12/12
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