Here is a story about corn from the New York Times that will help you understand the evolution of corn. I am sure there are more details available in more scientific publications if you want to find out more details
You will notice in this article how they used DNA and archeological research to confirm the same findings of the time involved. As well as analyses of residue to identify the material. Many fields of science coming together to show the whole story and confirm findings from one field of study through the use of another field of study
http://www.nytimes.com/2010/05/25/science/25creature.html?_r=0 These genetic discoveries inspired recent archeological excavations of the Balsas region that sought evidence of maize use and to better understand the lifestyles of the people who were planting and harvesting it. Researchers led by Anthony Ranere of Temple Universityand Dolores Piperno of the Smithsonian National Museum of Natural History excavated caves and rock shelters in the region, searching for tools used by their inhabitants, maize starch grains and other microscopic evidence of maize. In the Xihuatoxtla shelter, they discovered an array of stone milling tools with maize residue on them. The oldest tools were found in a layer of deposits that were 8,700 years old. This is the earliest physical evidence of maize use obtained to date, and it coincides very nicely with the time frame of maize domestication estimated from DNA analysis. |