Agriculture has started banking animal seed
Ninety percent of the nation's dairy cows—some 8.2 million animals—belong to a single breed: Holstein. Owing to the dairy industry's extensive reliance on artificial insemination using semen from only the choicest bulls, this Holstein population is heavily inbred. "Today, it's as if there were only about 35 unrelated cows [contributing genes to] our national Holstein herd," explains geneticist Harvey D. Blackburn of the U.S. Department of Agriculture (USDA).
If a crippling disease emerged that selectively struck down these black-and-white ruminants, what would milk producers do? They'd turn to Blackburn.