Standing on a mesa high above the town of Rifle, Colo., Andres Aslan is having a hard time staying quiet. The lanky geologist from nearby Colorado Mesa University normally speaks in a low-key professorial drone. But here, looking down at a sprawling river valley blazing with autumnal cottonwoods, his enthusiasm cranks up his volume. “This could be it,” says Aslan, gesticulating wildly. “This...
Food for Thought
Last May, tissues from the carcass of a North American cow turned up positive for bovine spongiform encephalopathy–the ailment responsible for mad cow disease. Within hours, the Canadian government traced the animal to the Alberta farm where it had been raised for its 8 years of life. In short order, other members of its herd were quarantined.
What made this...