1491

At the DNA level, all the major cereals -- wheat, rice, maize, millet, barley, and so on -- are surprisingly alike.  But despite their genetic similarity, maize looks and acts different from the rest.  It is like the one redheaded early riser in a family of dark-haired night owls.  Left untended, other cereals are capable of propagating themselves.  Because maize kernels are wrapped inside a tough husk, human beings must sow the species -- it cannot reproduce on its own...no wild maize ancestor has ever been found, despite decades of search.  Maize's closest relative is a mountain grass called teosinte that looks nothing like it...And teosinte, unlike wild wheat and rice, is not a practical food source; its "ears" are scarcely an inch long and consist of seven to twelve hard, woody seeds.  An entire ear of teosinte has less nutritional value than a single kernel of modern maize...

...the modern species [of maize] had to have been consciously developed by a small group of breeders who hunted through teosinte strands for plants with desired traits.  Geneticists from Rutgers University...estimated in 1998 that determined, aggressive, plan breeders -- which Indians certainly were -- might have been able to breed maize in as little as a decade...modern maize was the outcome of a bold act of conscious biological manipulation -- "arguably man's first, and perhaps his greatest, feat of genetic engineering," [Nina Federoff]..."To get corn out of teosinte is so -- you couldn't get a grant to do that now, because it would sound so crazy...Somebody who did that today would get a Nobel Prize!  If their lab didn't get shut down by Greenpeace, I mean."

That is from 1491: New Revelations of the Americas Before Columbus, by Charles C. Mann.  I loved this book, which also tells you why Norte Chico, at its peak, may have been as advanced as the Sumerians.  The book covers much of the New World, and the evidence in this area is in general muddy.  So the text is virtually certain to contain mistakes.  But the judgments are generally well-reasoned, the author is remarkably well-read, and the area I know best -- the Nahua culture of early Mexico -- is presented in a sober and balanced manner.