I was re-reading Charles C. Mann's 1491 the other day, and the question of how maize was developed from teosinte has stuck with me.

In the book, Mann references the fact that no one was quite sure how Indians developed the various species of corn that were widespread in the Americas, given that the ancestor of corn plants (teosinte) has a hard covering over its kernels and produces only a few seeds per plant. Mann's book was most recently updated in 2006, so I'm wondering if there has been any new scholarship on the subject in recent years.

Thanks in advance for any help!