For centuries, the Native American city of Cahokia thrived along the Mississippi River. At its peak around the year 1200 AD, Cahokia was the largest pre-Columbian city in North America, home to an estimated 15,000 to 40,000 people. However, by the 14th century, Cahokia had been mysteriously abandoned.

Until now, the precise reason for Cahokia's decline had remained unknown. However, new research using ancient poop has shed light on the city's fate.

The study, published in the journal Nature, analyzed human fecal samples found in Cahokia latrines. These samples contained remnants of parasites and microscopic plant fragments that provided crucial insights into the diet and health of Cahokia's residents.

According to the findings, Cahokia's inhabitants primarily relied on maize and other starchy plants for their sustenance. However, the frequency of maize and squash in their diet varied significantly over time. These variations coincided with climatic shifts and periods of drought, indicating that Cahokia's food supply was highly vulnerable to climatic fluctuations.

During periods of drought, maize production declined, and Cahokia's inhabitants were forced to turn to other, less favorable food sources, such as wild fruits and nuts. This change in diet led to nutritional deficiencies and increased the prevalence of parasitic diseases, weakening the population's overall health.

The study suggests that prolonged periods of drought, possibly exacerbated by climate change, ultimately led to the collapse of Cahokia's agricultural system, resulting in food shortages, widespread disease, and the eventual abandonment of the city.

The implications of this research extend far beyond Cahokia. It underscores the profound impact that climate change has had on human societies throughout history and highlights the vulnerability of complex civilizations to environmental shifts and variations in their food supply.