The run-off of ancient human poop is helping to uncover the story of a Maya population in the lowland city of Itzan, present-day Guatemala. By taking a deep look at the organic contents that have seeped out of this poop, archeologists were able to discover how this civilization rose and fell in multiple waves, most likely mirroring the fluctuation of droughts and wet periods that swept the region.
As reported recently in the journal Quaternary Science Reviews, archeologists at McGill University and Concordia University in Canada have closely analyzed the make-up of fecal stanols, organic molecules that originate in the guts of humans and persist in sediment for hundreds to thousands of years, found at the bottom of a nearby lake in Peten, Guatemala.
Through studying the composition of fecal stanols, scientists can get some feel of the population’s size, diet, and health, as well as any changes in agriculture and land use patterns. Typically, you might expect researchers to study the archaeological remains of their buildings and burials, but the humid jungle environment can be unforgiving towards such physical remains, leading this team to use this inventive method.
“This research should help archaeologists by providing a new tool to look at changes that might not be seen in the archaeological evidence because the evidence may never have existed or may have since been lost or destroyed,” Benjamin Keenan, first study author and candidate in the Department of Earth and Planetary Sciences at McGill, said in a statement. “The Maya lowlands are not very good for preserving buildings and other records of human life because of the tropical forest environment.”
The evidence from fecal stanols shows that humans were present in this area around 3,300 years ago, some 650 years before the archaeological evidence suggests. They found that the Maya population in the area declined due to drought during three different periods: between 90 to 280 CE, between 730 to 900 CE, and during the lesser-studied period between 1350 to 950 BCE. Rain also took its toll, with an extremely wet period from 400 to 210 BCE also causing population decline, perhaps due to crop failure.
Their findings suggest that a small portion of the Maya continued to occupy the area after the so-called “collapse” of the Classic Maya civilization around 1,000 years ago. As others have suggested, the team additionally found a large population spike around the same time as a historical record of refugees fleeing the Spanish attack of 1697 CE on the last Maya stronghold in the southern Maya lowlands, Nojpeten.
“It is important for society generally to know that there were civilizations before us that were affected by and adapted to climate change,” explained Peter Douglas, senior study author and an assistant professor in the Department of Earth and Planetary Sciences. “By linking evidence for climate and population change we can begin to see a clear link between precipitation and the ability of these ancient cities to sustain their population.”
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