Imitation is the most sincere form of flattery -- especially in the predator/prey1/poison cycle. In nature, bright colors are basically neon signs（霓虹灯） that scream, Dont eat me! But how did prey evolve these characteristics When did predators2 translate the meaningIn the current issue of the journal PLOS ONE, researchers at Michigan State University reveal that these color-coded communiqus evolve over time through gradual steps. Equally interesting, the scientists show how drab-colored, oft-eaten prey adopt garish3（过分鲜艳的） colors to live long and prosper4, even though they arent poisonous, said Kenna Lehmann, MSU doctoral student of zoology5.In some cases, nonpoisonous prey gave up their protection of camouflage6 and acquired bright colors, said Lehmann, who conducted the research through MSUs BEACON7 Center for the Study of Evolution in Action. How did these imitators get past that tricky8 middle ground, where they can be easily seen, but they dont quite re百度竞价推广ble colorful toxic9 prey And why take the riskThey take the risk because the evolutionary10 benefit of mimicry11 works. A nontoxic imposter benefits from giving off a poisonous persona, even when the signals are not even close. Predators, engrained to avoid truly toxic prey, react to the impersonations and avoid eating the imposters（冒名顶替者）.An example of truly toxic animals and their imitators are coral snakes and king snakes. While coral snakes are poisonous, king snakes are not. Even though king snakes are considered imperfect mimics12, they are close enough that predators dont bother them.Why dont all prey have these characteristics, and why dont the imitators evolve to develop poison instead Leaving the safety of the cryptic13（神秘的）, camouflage（伪装，掩饰） peak to go through the exposed adaptive valley over many generations is a dangerous journey, Lehmann said.To take the risk of traversing the dangerous middle ground -- where they dont look enough like toxic prey -- is too great in many cases, she said. Toxins14 can be cosplaytly15 to produce. If prey gain protection by colors alone, then it doesnt make evolutionary sense to expend16 additional energy developing the poison.The results suggest that these communicative systems can evolve through gradual steps instead of an unlikely large single step. This gives insight into how complex signals, both sent and received, may have evolved through seemingly disadvantageous steps.Rather than conduct experiments of voracious17 predators chasing and eating, or completely avoiding, prey, the scientists used evolving populations of digital organisms in a virtual world called Avida.Avida is a software environment developed at MSU in which specialized18 computer programs compete and reproduce. Because mutations happen when Avidians copy themselves, which lead to differences in reproductive rates, these digital organisms evolve, just like living things.Additional MSU scientists who contributed to the study include: Brian Goldman, Ian Dworkin, David Bryson and Aaron Wagner.This research was funded by the National Science Foundation.
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1 prey n.被掠食者，牺牲者，掠食；v.捕食，掠夺，折磨 参考例句： Stronger animals prey on weaker ones.弱肉强食。 The lion was hunting for its prey.狮子在探寻猎物。