For their part, researchers have long been fascinated with mimicry, and for some contemporaries of Darwin like naturalist Alfred Russel Wallace, it was mimicry and camouflage that helped convince them of the power of natural selection. Nature selects for successful traits: Insects that can blend in with their environments are less likely to be eaten and are able to pass on their genes-and their natural disguises-to future generations. (Related: "Photo Gallery: Masters of Undersea Camouflage.")

But according to a study released yesterday, it turns out that a certain type of leaf mimicry dates back much further than experts believed, to the time of the dinosaurs. (See "Stick Insects Have Mimicked Plants Since the Age of Dinosaurs.")

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