Survival of the Fittest

Man has a long habit of tinkering with his natural habitat, often with unintended or unfortunate results. Kudzu, for instance, planted in the United States to prevent soil erosion in the 1940s, went on to entangle telephone poles, trees and fences over seven million acres of the American South. Gypsy moths, a pest that devours oak and aspen trees, were originally brought to the U.S. in 1869 to breed stronger silkworms. But as our understanding of biology and genetics grow more sophisticated, so do our attempts to use plants and animals to rein in threats in our environment. The trick will...