Maize, known as corn in the U.S., a globally dominant crop, has a more complex origin than previously thought. According to a recent study in science, this vital crop for both human and animal consumption, and with significant cultural importance, especially in the Americas, is actually a hybrid. Researchers now confirm that modern maize descends from a crossbreed formed over 5000 years ago in central Mexico.
Jeffrey Ross-Ibarra's team at the University of California, Davis, analyzed over a thousand maize and related wild samples. They discovered that modern maize carries approximately 20% of its genome from a highland teosinte, a wild grass variant. This finding challenges the long-held belief that maize evolved exclusively from lowland teosinte in southwest Mexico about 9,000 to 10,000 years ago.
This hybridization with highland teosinte, happening millennia after initial domestication, propelled maize to become a widely cultivated and essential food staple. Archaeological records support this timeline, noting maize's increasing significance in ancient societies.
Key genetic traits identified in the study, such as cob size and flowering time, hint at the reasons behind maize's adaptability and yield improvements. The concept of "hybrid vigor" is also a vital factor, with highland teosinte contributing genomic segments that are more robust and less mutation prone.
Ross-Ibarra’s research, fueled by a $1.6 million grant from the National Science Foundation, is part of a broader project to explore the co-evolution of maize and humans in the Americas. This interdisciplinary approach, combining genetics and archaeology, aims to answer many questions about maize's origins and spread. Source : wisconsinagconnection