Butterfly Secrets

In the highlands of central Mexico, millions of monarch butterflies soon will stir from their winter torpor, rising from groves of oyamel firs like flowers taking flight. Their unique annual migration offers scientists a rare insight into the molecular biology of time and travel.

"What good is a butterfly?" said entomologist Lincoln Brower at Virginia's Sweet Briar College. "It can tell you about the fundamental biology of all creatures on this earth. There is something so fundamental about finding your way." Go to--- http://online.wsj.com/article/SB120233944314148959.html?mod=hpp_us_inside_today