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  • General

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  • 微观进化和宏观进化

    A hand spraying pesticide at a fly, illustrating pesticide use against insect resistance.

    Why do pesticides sometimes stop working?
    ::为什么杀虫剂有时会停止工作?

    Pesticides were designed to kill bothersome . However, sometimes these pesticides will stop working. A pesticide that has worked in the past may no longer kill a particular type of insect. This is due to the development of resistance in the of insects. The development of resistance to pesticides is one example of microevolution , a small change in a population.
    ::杀虫剂的设计是为了杀死麻烦的害虫。然而,有时这些杀虫剂会停止工作。过去有效的杀虫剂可能不再杀死特定种类的昆虫。这是因为昆虫的抗药性有所增强。对杀虫剂的抗药性发展是微进的一个例子,这是人口小幅变化。

    Microevolution and Macroevolution
    ::微观进化和宏观进化

    Does evolution only happen gradually through small changes? Or is it possible that drastic environmental changes can cause new species to evolve? Or can both small and large changes occur?
    ::进化是否只能通过小的变化逐渐发生? 还是环境的急剧变化有可能导致新物种的进化? 还是可能同时发生大小变化?

    Evolutionary changes can be both big and small. Some evolutionary changes do not create new species, but result in changes at the population level. A population is a group of organisms of the same species that live in the same area ( Figure ). But what exactly is the definition of a species? A species is a group of organisms that have similar characteristics (they are genetically similar) and can mate with one another to produce fertile offspring .
    ::进化变化可以是大变化和小变化。 某些进化变化不会创造新的物种,而是在人口水平上导致变化。 种群是同一物种的一组生物,生活在同一个区域(图 ) 。 但是,物种的定义到底是什么? 物种是具有类似特性(它们在基因上相似)的一组生物,它们可以相互交配,产生肥沃的后代。

    A school of fish swimming together in a coral reef ecosystem.

    This school of fish are considered members of the same species because they are able to mate with one another. They are also considered a population because they live in the same part of the ocean.
    ::这种鱼类学派被认为是同一鱼种的成员,因为它们能够相互交配,它们也被认为是种群,因为它们生活在海洋的同一部分。

    Microevolution
    ::微进

    You already know that evolution is the change in species over time. Most evolutionary changes are small and do not lead to the creation of a new species. When populations change in small ways over time, the process is called microevolution . Microevolution results in changes within a species.
    ::您已经知道进化是物种随时间的变化。 大多数进化变化是小的,不会导致新物种的产生。 当种群随时间的细小变化, 过程被称为微进。 微进导致物种内部的变化。

    An example of microevolution is the evolution of mosquitoes that cannot be killed by pesticides, called pesticide-resistant mosquitoes. Imagine that you have a pesticide that kills most of the mosquitoes in your state. Through a random , some of the mosquitoes have resistance to the pesticide. As a result of the widespread use of this pesticide, most of the remaining mosquitoes are the pesticide-resistant mosquitoes. When these mosquitoes reproduce the next year, they produce more mosquitoes with the pesticide-resistant trait. Soon, most of the mosquitoes in your state are resistant to the pesticide.
    ::微进的一个例子就是蚊子的进化,这些蚊子不能被杀虫剂杀死,称为抗杀虫剂的蚊子。想象一下,你拥有一种杀死大部分蚊子的杀虫剂。一些蚊子通过随机方式对杀虫剂有抵抗力。由于广泛使用这种杀虫剂,剩下的蚊子大多是抗杀虫剂的蚊子。当这些蚊子在明年繁殖时,它们生产出更多耐杀虫剂的蚊子。很快,你所在国家的蚊子大多数都抗杀虫剂。

    This is an example of microevolution because the number of mosquitoes with this trait changed. However, this evolutionary change did not create a new species of mosquito because the pesticide-resistant mosquitoes can still reproduce with other non-pesticide-resistant mosquitoes.
    ::这是微进的例子,因为具有这种特性的蚊子数量发生了变化。 然而,这种进化变化并没有产生一种新的蚊子种类,因为抗杀虫剂的蚊子仍然可以与其他非抗杀虫剂的蚊子繁殖。

    Macroevolution
    ::进进 进 进 进

    Macroevolution refers to much bigger evolutionary changes that result in new species. Macroevolution may happen:
    ::宏观进化是指导致新物种的更大的进化变化。

    1. When microevolution occurs repeatedly over a long period of time and leads to the creation of a new species.
      ::当微演化在很长一段时间内反复发生并导致新物种的产生时。
    2. As a result of a major environmental change, such as a volcanic eruption, earthquake, or an asteroid hitting Earth, which changes the environment so much that leads to large changes in the traits of a species.
      ::由于火山爆发、地震或小行星撞击地球等重大环境变化,环境发生了很大变化,导致物种特性发生了巨大变化。

    After thousands of years of isolation from each other, Darwin's finch populations have experienced both microevolution and macroevolution. These finch populations cannot breed with other finch populations when they are brought together. Since they do not breed together, they are classified as separate species.
    ::在相隔数千年的隔绝之后,达尔文的硬实力人口经历了微观革命和宏观革命。 这些硬实力人口在聚集在一起时无法与其他硬实力人口一起繁殖。 由于它们不共同繁殖,它们被划为单独的物种。

    Summary
    ::摘要

    • Microevolution is the process by which organisms change in small ways over time.
      ::微生物的进化是生物随着时间的流逝而发生微小变化的过程。
    • Macroevolution refers to larger evolutionary changes that result in new species.
      ::宏观进化是指导致新物种的较大进化变化。

    Explore More
    ::探索更多

    Use the resources below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    Explore More I
    ::探索更多

    • Microevolution vs. Macroevolution at  (5:21)

      :sad5:21) 微变与宏观变 (5:21)
    1. How does microevolution differ from macroevolution with regard to species?
      ::在物种方面,微变与巨变有何不同?
    2. What are four factors believed to cause microevolution? How do these four factors relate to macroevolution?
      ::四个因素被认为导致微变的因素是什么?这四个因素与宏观变迁有什么关系?
    3. What happens to the allele frequency of genes in a population that has undergone microevolution?
      ::在经历微进的人口里,基因的等离子频率会怎样呢?
    4. What is phyletic gradualism? How does this differ from "punctuated equilibrium"?
      ::什么是植物渐进主义?这与“流行平衡”有什么不同?

    Explore More II
    ::探索更多情况二

    • Cambrian Explosion - Shape of Life
      ::Cambrian爆炸 -- -- 生命的形状

     

    1. What was the Cambrian Explosion? When did it occur?
      ::Cambrian爆炸是什么时候发生的?
    2. Do you think the Cambrian Explosion represents microevolution or macroevolution? Explain your reasoning.
      ::你认为坎布里安爆炸代表了微进还是宏观进化?解释一下你的推理。
    3. What are some of the ideas about the cause of the Cambrian Explosion?
      ::坎布里安爆炸的原因是什么?
    4. How much similarity can be seen between the current body plans of organisms and the body plans seen in fossils from the Cambrian Period?
      ::现有生物体的计划与Cambrian时期化石中发现的身体计划之间有多大的相似性?

    Review
    ::回顾

    1. How do you know if two related organisms are members of the same species?
      ::你怎么知道两个相关生物体是否属于同一物种?
    2. Compare and contrast microevolution and macroevolution.
      ::对比和对比微观进化和宏观进化。
    3. Does microevolution lead to a new species? Why or why not?
      ::微进是否导致新的物种?为什么或为什么不是?
    4. What is the outcome of many microevolution events?
      ::许多微观革命事件的结果是什么?