Fifty years ago, one of the great truths that no serious person dared challenge was that humanity was just a few ticks away from the detonation of what Stanford’s Paul Ehrlich dubbed “the population bomb,” in his book of the same name. The world, everyone assumed, would be awash in (even more) hungry mouths to feed.

“The battle to feed all of humanity is over,” intoned Ehrlich with all the certitude of a future MacArthur “Genius” grant recipient. “In the 1970s . . . hundreds of millions of people are going to starve to death in spite of any crash programs embarked upon now. At this late date