Out of Eden

Now as never before, exotic animals and plants are crossing the globe, borne on the swelling tide of human traffic to places where nature never intended them to be. Bird-eating snakes hitchhike to Hawaii in the landing gear of airliners; pernicious European zebra mussels, riding in ships' ballast water, disrupt aquatic ecosystems across the United States; feral camels and poisonous foreign toads plague Australia; giant Indonesian pythons lurk beneath homes in suburban Miami. As alien species jump from place to place and increasingly crowd native and endangered species out of existence, biologists speak fearfully of "the homogenization of the world." Never mind bulldozers and pesticides: the fastest growing threat to biological diversity may be nature itself.