The big bad wolf

It's been nearly 100 years since 22-year-old graduate biology student Aldo Leopold shot and killed one of the last wolves in New Mexico. He later recounted the event with regret, describing having watched in the animal's eyes the "dying of that fierce green fire." Decades later, as one of the most influential conservation biologists of his day, Leopold would be among the first to articulate the importance of predators in healthy ecosystems, calling in 1944 for the reintroduction of wolves to Yellowstone National Park.

Niall Ferguson

April 30, 2008