Greenup of the Planet Is Not Black-and-White

Every spring, the Earth blooms. Scientists call it greenup: New buds sprout, fresh leaves unfurl, and continents turn green. Exactly when greenup takes place each year is the result of an algorithm embedded in the DNA of plants. They track the rising temperature in spring, gauge the rainfall, measure the lengthening days, and then calculate when to start growing. People have been trying to figure out the greenup algorithm for millennia.

Source: Wire News, 11/09/07