Like a floating exclamation point, a brushstroke on the breeze, a butterfly dances by us, eager to move onto the next bit of milkweed, or flowery front yard, or lush neighborhood. Stream Los Angeles ...

A monarch butterfly (Dannaux plexippus) flaps its wings in Piedra Herrada Sanctuary, Mexico. Might this start a chain of events that results in a tornado in Texas? Photograph by Jaime Rojo In 1961, ...

You’ve probably heard of the butterfly effect, the idea that a tornado can be formed by a minor perturbation such as a butterfly flapping its wings a mile away. Every action has a consequence, for ...