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When a yeast cell falls onto an apple in the spring, life is good. Plentiful food and good weather maintain growth and division. But the good times don't last forever. "When resources dwindle due to competition, it makes sense to kill the less fit cells," says Frank Madeo of the Institute for Physiological Chemistry in Tübingen, Germany.
Madeo and colleagues have mimicked the apple scenario in cultures to show that old