Sonoran Desert : Wiki Commons
Human/environment interactions have a history as long as the existence of our species on the planet. Our hominid ancestors began polluting their environment nearly 700,000 years ago with the control of fire. Humans have never looked back.
The modern phenomenon of global warming is very likely the direct result of human pollution and destruction of the environment. Most scientists recognize the steep increase in toxic gases, such as methane, that have been released into the atmosphere in large quantities starting at the beginning of the Industrial Revolution. By all appearances, the interaction between humans and the environment is mainly unidirectional—in which the environment continues to deteriorate as global human populations swell.
But Mother Nature does have her say. Major natural disasters within the past decade have resulted in major losses of human life and property and have directly affected how humans adapt and continue to live in these areas.
Dr. James Watson, assistant curator of bioarchaeology at Arizona State Museum, has been working to better understand how humans and the environment in the Sonoran Desert interacted in the past. His work particularly focuses on how humans use the landscape to their advantage…or how the landscape determines how humans can use it based on the level of technological complexity available to them at the time. His recent research describes how the earliest village settlements in the Sonoran Desert utilized the geomorphological characteristics of local landscapes to facilitate a sophisticated form of irrigation agriculture. These indigenous technological advances date to nearly 3,000 years ago and represent some of the earliest canal irrigation in North America.
Watson’s research highlights the importance of understanding the role of humans in constructing environments in the past and how environmental change—both long term and small scale—causes human populations to react and alter their adaptive strategies.
The two chapters co-authored by Watson, published in a volume dedicated to “Reconstructing Human-Landscape Interactions” from SpringerBriefs in Earth Systems Sciences, describe how long-term environmental trends encourage stable adaptations within local environments, but when climate changes, it can be quick and human groups must adapt equally as quickly, resulting in confusing signatures in the archaeological record.The results of these studies identify that early farmers in the Sonoran Desert successfully adapted to both large and small environmental changes by employing different technological strategies.
Examples from the articles describe how the early farmers used the steep slope of the La Playa site (located in northern Sonora, Mexico) to create constant water flow through the site, which contributed too much of the soil deposition at the site from 4,500 years ago to about 2,000 years ago. After that time, a major drying trend and possibly drought conditions contributed to major erosion events and caused the reconfiguration of settlements throughout the region. This is identified at La Playa as a concentrated layer of artifacts in the site’s stratigraphy, just below the modern ground surface, where the objects had eroded out of their original contexts and been spread around the site by natural processes (erosion and water).