Coprolites reveal pre-Columbian Caribbean ate a variety of plants

Poop can tell a lot about people’s diet

According to a study by Jelissa Reynoso-Garcia from the University of Puerto Rico and colleagues that was published on October 11, 2023, in the open-access journal PLOS ONE, two pre-Columbian Caribbean cultures consumed a wide variety of plants, including maize, sweet potato, and peanuts, as well as tobacco and cotton traces.

Coprolites, or mummified poo, can provide information on diet and lifestyle. To determine what these people consumed, Reynoso-Garca and colleagues examined plant DNA isolated from coprolites taken from the archaeological sites of two pre-Columbian cultures (Huecoid and Saladoid).

As reported here, ten coprolite samples collected from the La Hueca archaeological site in Puerto Rico were meticulously processed to extract and analyze plant DNA. They examined the plant DNA that had been extracted with a database of various coprolite samples and current plant DNA sequences.

The findings indicate that Huecoid and Saladoid people had a complex and varied diet, as evidenced by the discovery of sweet potatoes, wild and domesticated peanuts, chili peppers, a domesticated strain of tomatoes, papaya, and maize. The examination also revealed the presence of tobacco, presumably as a result of chewing tobacco, inhaling tobacco powder, or using tobacco as a food additive for therapeutic and/or hallucinogenic effects.

Another unexpected discovery was the presence of cotton, maybe as a result of the employment of powdered cotton seeds for oil or because women wet the cotton strands with their saliva when weaving, leaving strands in their mouths. Cassava, manioc, or yucca (Manihot esculenta) eating was not documented by the authors, even though chroniclers frequently referred to this plant as a staple diet in the pre-Columbian Caribbean.

The intricate grating and drying methods for cassava described in these reports may have damaged the plant’s DNA, or it may have been a seasonal staple diet, the authors say.

The Huecoid and Saladoid people likely ate other plants or fungi not mentioned here because of food preparation methods, the fact that each coprolite sample only represents a snapshot of what one particular person had recently eaten, and the fact that the authors were only able to identify plants in current DNA sequence databases (not capturing any now-extinct, rare, or non-commercial crops). Yet, the scientists anticipate that their analysis can shed further light on pre-Columbian life in the Americas.

Dr. Toranzos adds, “Who would have thought that something that we avoid even looking at would contain so much information? It’s especially incredible that this is so even after thousands of years”.