In the Southwest, the chili pepper is practically a dietary staple. It gives salsa a spicy crunch, it brings depth to Mexican sauces, and provides an extra kick to Sonoran hot dogs
Plenty of other world cuisines rely on it too, from China to India to Thailand. But Latin America, researchers have confirmed, is where it started.
In a study of global significance, researchers have figured out where the first domesticated chili pepper crop was farmed. University of Arizona ethnobiologist and agroecologist Gary Nabhan and other researchers in the U.S., France and Kenya have determined that the plant was first cultivated in central-east Mexico, likely in the Valley of Tehuacán.
The team's evidence indicates that the first cultivators of the chili pepper inhabited the area about 6,500 years ago. They were speakers of the Oto-Manguean language stock – an ethnic Mexican Indian language that makes up 174 different dialects.
The team's paper, "Multiple Lines of evidence for the Origin of Q:1 Domesticated Chili Pepper, Capsicum annuum, in Mexico," appears in the April 29 issue of the Proceedings of the National Academy of Sciences.
The article is part of a special series of research papers PNAS just published on different aspects of domestication, including plant and animal domestication.
Led by University of California, Davis, plant scientist Paul Gepts, the international team determined that the crop's region of origin extended from the area that is now southern Puebla and northern Oaxaca to southeastern Veracruz, and was further south than previously thought.
"Identifying the origin of the chili pepper is not just an academic exercise," said Gepts, lead author of another paper PNAS released in the series. "By tracing back the ancestry of any domesticated plant, we can better understand the genetic evolution of that species."
Nabhan, who holds the Kellogg Endowed Chair in Sustainable Food Systems and is a researcher at the UA Southwest Center, noted that this new knowledge "better equips us to develop sound genetic conservation programs."
For the current study, the team employed a novel and innovative approach, using multiple lines of evidence to pinpoint where humans first cultivated the chili pepper. The team used two traditional investigative approaches, relying on archaeological and genetic data.
The team's scientific methods and findings have important implications for understanding nutrition-related diseases, the use of crops for health-related benefits and crop production and resiliency into the future.
"Chilies are one of the most important spices in the world, and are an important part of our cultural legacy," Nabhan said.
"We are helping scientists all around the world to understand the ecological, cultural and historical relationships of something that affects anyone that uses chilies."