Xihuatoxtla Rock Shelter, Mexico

Earliest corn domestication in a rock shelter (8,700 years old)

 (originally posted 7/28/2020)

Learned about the earliest domesticated corn today.  In the early 1930s, it was discovered that corn was derived from a grass called Teosinte.  This is native to the Central Balsas River Valley in Mexico, somewhat south of Mexico City.  So scientists relatively recently looked in a number of caves in that area for the earliest signs of Corn domestication.  They found it in the Xihuatoxtla Rock Shelter in 2007.  This is basically an overhang beneath a giant rock that has been used by humans from 11 thousand to 4 thousand years ago.  They found a Milling Stone and several Hand Stones with the ground up remains of corn and squash that were 8.7 thousand years old.  The locals seemed to be hunting and experimenting with various plants.  Back then, the corn kernels would have been unrecognizable and probably weren’t used for food.  It would take several thousand more years before the kernels were big enough and the cobs had enough rows to be worth eating, with the earliest sign of corn in a humans diet being in Belize 4,700 years ago, and of being a staple 4,000 years ago.  So, it is surmised that in the earlier days of corn domestication, it would have been used for some kind of sugary fermented beverage.  Corn would go on to fuel the civilizations in Mesoamerica and the Andes Mountains, and is today the number one grown crop in the world.