Almost everything we eat has been altered by humans, often by generating random mutations in the DNA of seeds used to breed plants with desired traits. Thus, the distinction between “natural” and “unnatural” has been obscured. Red grapefruits created by neutron radiation, seedless watermelons produced with the chemical compound colchicine, apple orchards in which every tree is a perfect genetic clone of its neighbors—none of these aspects of modern agriculture is natural. Yet most of us eat these foods without complaint.
