WASHINGTON — Almost 24 centuries after the Greek philosopher Aristotle wrote his book, "On the Movement of Animals," modern scientists are still struggling to understand how, why, when and where living creatures move.

Whether an organism drifts in the sea, swims, wriggles, crawls, walks, runs, jumps, flies or casts its seeds upon the wind, movement is essential to life, they say. No matter how big or little it is, it's got to get away from its birthplace to find food, escape predators and reproduce.

"From microbes to trees to elephants . . . the movement of individual organisms is one of the most fundamental features of life on Earth," Ran Nathan, an ecologist at Hebrew University of Jerusalem, wrote in the Proceedings of the National Academy of Sciences. "The rich variety of movement modes among microorganisms, plants and animals has fascinated mankind since time immemorial." » read more

Near Mark Oldfield's desk at the California Department of Conservation sits a ream of copy paper that is more than a routine office commodity.

Made in part from recycled fiber, it is a symbol of the state's green spirit, one ream among thousands backing the department's claim that it is a champion of the environment – and complies with state law requiring it to buy recycled paper.

There is a dark side to those sheets of bright, white paper: the part that isn't recycled comes from trees logged in the biologically rich but endangered forests of Indonesia. » read more

On a small lot tucked between conventional homes on Boise Avenue, Mark Lung is hard at work stacking bales of straw and mixing mud.

He is building a new home using local, recycled agricultural waste to form and insulate exterior walls. Plaster made from clay, sand, lime, straw and water will be used on both the interior and exterior instead of drywall, siding and paint.

Similar in appearance to Southwestern adobes, straw bale structures are earth-friendly and energy-efficient, Lung said. » read more