Science: Nature's Housekeeper

"Wolves have been pushed around,'' says Biologist C. Gordon Fredine of the National Park Service. "People resent them."

Wolves resent people, too, occasionally eating them down to their boots. Result: U.S. wolves have been all but exterminated by resentful U.S. people. But Biologist Fredine reports that a study being conducted on Lake Superior's Isle Royale by the Park Service and Purdue University shows that wolves serve a useful purpose in the balance of nature.

Isle Royale, a national park, is 45 miles long and 20 miles from the Ontario shore. Originally it was covered with forest. Moose arrived about 1900, probably crossing from...