On trying to reduce my backlog of reading, I noticed an article in the November 14 Science about teosinte corn (maize, for my cross-Atlantlete readers).
The kernel of the story is that several traits of modern corn had already been established by human interference at least 4,400 years before the present. Selective breeding is genetic modification.
So genetically modified foods have a deeper history than we thought, and I perhaps need to revise my table of agricultural stages.
Nothing is ever as simple as we would like. Prehistoric popcorn anyone?