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来源：学生作业帮助网 编辑：作业帮 时间：2024/04/19 23:50:53

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生物变异像赌博,绝大多数情况都会导致生物不适应环境而淘汰,但极个别时候会产生新基因新性状,这是生物进化的基础

总的来说：变异是生物进化的内在因素。
现代生物理论认为：生物的变异是不定向的，生物生活在一定的环境中，而环境是不断变化的，生物产生的大部分变异不能适应变化的环境，因此我们说生物个体的变异大多对生物有害，只有少数变异有利于生物个体。具有有利变异的生物在生存斗争中更容易生存下来并繁衍子代。并可能把有利变异传递给子代。当这些微小的有利变异在子代中积累到一定程度时就可能产生新物种...

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总的来说：变异是生物进化的内在因素。
现代生物理论认为：生物的变异是不定向的，生物生活在一定的环境中，而环境是不断变化的，生物产生的大部分变异不能适应变化的环境，因此我们说生物个体的变异大多对生物有害，只有少数变异有利于生物个体。具有有利变异的生物在生存斗争中更容易生存下来并繁衍子代。并可能把有利变异传递给子代。当这些微小的有利变异在子代中积累到一定程度时就可能产生新物种

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生物变异对生物生存发展 有积极作用
有利于生物更好的适应环境
有利于后代发展

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