The loss of biological diversity does not only affect wildlife and natural ecoystems, but global agriculture and food production as well. Agricultural production relies on a relatively narrow selection of domesticated varieties of plants and animals, such as wheat, rice, and cattle. (Of the five thousand plant species humans have historically consumed, twenty presently make up around 90 percent of the world’s food supply.) In addition, farmers depend on numerous other species of life, including soil microbes and insect pollinators, to grow crops.

Concerns have been voiced regarding both the loss of species diversity and the loss of genetic diversity within species in the agricultural sphere. The United Nations Food and Agriculture Organization (FAO) has estimated that since the beginning of the twentieth century, about 75 percent of the genetic diversity of agricultural crops worldwide has been lost. In 1900, for...