Section outline

  • General

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  • 化石

    What you will learn
    ::你会学到什么

    • How fossils provide evidence for evolution
      ::化石如何为进化提供证据

    A fossilized dinosaur skeleton embedded in a rock, representing evidence of extinct species.

    Would this be evidence of evolution?
    ::这是进化的证据吗?

    Fossils, like this dinosaur , provide evidence of that lived in the past and have since gone extinct. In other words, these fossils are evidence of evolution.
    ::化石和这种恐龙一样,提供了过去曾生活过、后来绝种的证据。 换句话说,这些化石是进化的证据。

    Fossil Evidence
    ::化石证据

    In his book On the , included evidence to show that evolution had taken place. He also made logical arguments to support his theory that evolution occurs by . Since Darwin’s time, much more evidence has been gathered. The evidence includes a huge number of fossils. It also includes more detailed knowledge of living things, right down to their .
    ::在他的书《关于进化的书 》 ( On the ) 中,包含了表明进化已经发生的证据。 他还用逻辑论据支持他的演化理论。 自达尔文时代以来,已经收集了更多的证据。 证据包括大量的化石。 证据还包括关于生物的更详细知识,直达它们。

    Fossils are a window into the past. They provide clear evidence that evolution has occurred. Scientists who find and study fossils are called paleontologists . How do they use fossils to understand the past? Consider the example of the horse, shown in the Figure . The shows how the horse evolved.
    ::化石是通向过去的一个窗口。 它们提供了已经发生进化的清晰证据。 发现和研究化石的科学家被称为古生物学家。 他们如何使用化石来理解过去? 想想马的例子, 见图 。 它显示了马是如何进化的。

    Evolutionary timeline of horses, showing changes in height, molar teeth, and forefeet.
    Evolution of the horse. Fossil evidence, depicted by the skeletal fragments, demonstrates evolutionary milestones in this process. Notice the 57 million year evolution of the horse leg bones and teeth. Especially obvious is the transformation of the leg bones from having four distinct digits to that of today's horse.

    The oldest horse fossils show what the earliest horses were like. They were about the size of a fox, and they had four long toes. Other evidence shows they lived in wooded marshlands, where they probably ate soft leaves. Through time, the climate became drier, and grasslands slowly replaced the marshes. Later fossils show that horses changed as well.
    ::最古老的马化石展示了最早的马匹是什么样子。它们与狐狸差不多大小,有四只长脚趾。其他证据表明,它们生活在木质沼泽地,可能吃软叶子。随着时间的推移,气候变得干燥,草地逐渐取代了沼泽。后来的化石显示,马也变了。

    • They became taller, which would help them see predators while they fed in tall grasses.
      ::他们越高越好,在用高草喂食时, 就能帮助他们看到捕食者。
    • They evolved a single large toe that eventually became a hoof. This would help them run swiftly and escape predators.
      ::他们进化了一只大脚趾,最终变成了蹄子。这将有助于他们迅速逃跑并逃离掠食者。
    • Their molars (back teeth) became longer and covered with cement. This would allow them to grind tough grasses and grass seeds without wearing out their teeth.
      ::他们的齿轮(后牙)变长了,并被水泥覆盖。 这样可以让他们在不磨牙的情况下研磨坚硬的草和草籽。

    Similar fossil evidence demonstrates the evolution of the whale, moving from the land into the sea.   
    ::类似的化石证据表明鲸鱼的进化,从陆地向海洋移动。

     

     

     

    Science Friday : Millions of Fossils Can't Be Wrong
    ::科学星期五:数百万化石不可能错

    What’s in a tar pit? In this video by Science Friday , Dr. John Harris describes how the La Brea Tar Pit has come to accumulate so many fossils.
    ::焦油坑里有什么?在科学周五的这段影片中,约翰·哈里斯博士描述了La Brea Tar Pit是如何聚集这么多化石的。

     

     

    Summary
    ::摘要

    • Fossils provide a window into the past. They are evidence for evolution.
      ::化石为过去提供了一个窗口。它们是进化的证据。
    • Scientists who find and study fossils are called paleontologists.
      ::寻找和研究化石的科学家 被称为古生物学家

    Review
    ::回顾

    1. What is a fossil?
      ::什么是化石?
    2. How do paleontologists learn about evolution?
      ::古生物学家如何了解进化?
    3. Describe what fossils reveal about the evolution of the horse.
      ::描述化石揭示的马的进化过程