Question 47

The Chaco Canyon civilization in the American Southwest is celebrated for its complex social structure and monumental great houses. For years, the prevailing theory attributed the sudden abandonment of these settlements in the 12th century primarily to a severe, decades-long drought. However, recent bioarchaeological and geological studies have begun to paint a more nuanced picture involving human agency. Analysis of ancient packrat middens-rodent nests that preserve plant materials over millennia-demonstrates that the canyon was once surrounded by dense pinyon and juniper woodlands. Over centuries, the Chacoans harvested this timber extensively for construction and firewood. The removal of this critical ground cover likely triggered a cycle of soil erosion and arroyo cutting, which lowered the water table and decimated the maize crops upon which the society depended. Thus, while climate variability was undeniably a factor, the society's collapse was likely compounded by their unsustainable exploitation of the local environment, challenging the view that pre-colonial populations always lived in perfect equilibrium with their surroundings. Which of the following best summarizes the writer's argument regarding the decline of the Chaco Canyon civilization?