Are Humans Giving Animals Cancer?
"Tasmanian Devils are not the friendliest of animals," explains Kathy Belov as she tries to punch a skin sample from the ear of one of the famously ferocious marsupials. (This one is, fortunately, stuffed inside a burlap sack.) Belov, a geneticist at the University of Sydney, studies Devil Facial Tumor Disease, which has killed almost three quarters Tasmania's devil population. The unusual affliction, which rots the animals' faces off and causes them to starve to death, is the unintentional result of contact with humans: Early colonists' efforts to exterminate the creatures worked so well that they are now seriously inbred, making them vulnerable to this contagious cancer, which is spread by biting. Though the Tasmanian Devils' case is unique, conservationists are becoming increasingly concerned about other cancer outbreaks in disparate kinds of wildlife—and what role people played in causing them. Some more examples: