Air flows mostly in a one-way loop through the lungs of monitor lizards -- a breathing method shared by birds, alligators and presumably dinosaurs, according to a new University of Utah study. The findings -- published online Dec. 11 in the journal Nature -- raise the possibility this breathing pattern originated 270 million years ago, about 20 million years earlier than previously believed and 100 million years before the first birds. Why remains a mystery. "It appears to be much more common and ancient than anyone thought," says C.G. Farmer, the study's senior author and an associate professor of biology...