4.12 地理时间尺度
章节大纲
-
Which was first, the or the flower ?
::先是那朵花还是那朵花?Although the land plants were here before insects, the first flowers evolved long after the first insects. The first land plants did not have flowers. Today insects and flowers are so interconnected, it's hard to imagine one without the other.
::虽然陆地植物在昆虫之前就在这里, 第一批花是在昆虫之后很久才进化的。 第一批陆地植物没有花。 今天昆虫和花是紧密相连的, 很难想象没有其他的。Timeline of Evolution
::演变时间表For life to evolve from simple single-celled organisms to many millions of species of prokaryotic species to simple eukaryotic species to all the protists , , plants, and animals , took some time. Well over 3 billion years.
::生命从简单的单细胞生物演变为数百万种蛋白质物种,到简单的蛋白质物种, 植物和动物,需要一些时间。超过30亿年的时间。The Age of Earth
::地球的时代How old is Earth? How was it formed? How did life begin on Earth? These questions have fascinated scientists for centuries. During the 1800s, geologists, paleontologists , and naturalists found several forms of physical evidence that confirmed that Earth is very old.
::地球几岁?它是如何形成的?生命是如何在地球上开始的?这些问题让科学家迷恋了几个世纪。在1800年代,地质学家、古生物学家和自然学家发现了几种形式的物理证据,证实地球已经非常古老。The evidence includes:
::证据包括:-
of ancient sea life on dry land far from oceans. This supported the idea that the Earth changed over time and that some dry land today was once covered by oceans.
::在远离海洋的陆地上,古老的海洋生命在远远离海洋的干地上,这支持一种观点,即地球随时间而变化,今天有些干地曾经被海洋覆盖过。 -
The many layers of rock. When people realized that rock layers represent the
order
in which rocks and fossils appeared, they were able to trace the history of Earth and life on Earth.
::许多层的岩石。当人们意识到岩石层代表着岩石和化石的出现顺序时, 他们能够追踪地球的历史和地球上的生命。 -
Indications that volcanic eruptions, earthquakes, and erosion that happened long ago shaped much of the Earth’s surface. This supported the idea of an older Earth.
::很久以前发生的火山爆发、地震和侵蚀等迹象塑造了地球大部分表面。 这支持了地球老化的理念。
The Earth is at least as old as its oldest rocks. The oldest rock minerals found on Earth so far are crystals that are at least 4.404 billion years old. These tiny crystals were found in Australia. Likewise, Earth cannot be older than the solar system. The oldest possible age of Earth is 4.57 billion years old, the age of the solar system. Therefore, the age of Earth is between 4.4 and 4.57 billion years.
::地球至少同其最古老的岩石一样古老。迄今为止,地球上发现的最古老的岩石矿物是至少44.04亿年前的晶体。这些微小的晶体是在澳大利亚发现的。同样,地球不能比太阳系年长。地球最古老的年代是45.7亿年前的太阳系时代。因此,地球的时代在44亿到45.7亿年前。Geologic Time Scale
::地质时标Geologists and other Earth scientists use geologic time scales to describe when events happened in the history of Earth. The time scales can be used to show when both geologic events and events affecting plant and animal life occurred. The geologic time scale pictured below ( Figure ) illustrates the timing of events like:
::地球地质学家和其他地球科学家使用地质时间尺度来描述地球历史上发生的事件。时间尺度可用于显示影响动植物生命的地质事件和事件的发生时间。-
Earthquakes.
::地震 -
Volcanic eruptions.
::火山爆发 -
Major erosion.
::严重侵蚀。 -
Meteorites hitting Earth.
::陨石撞击地球 -
The first signs of life forms.
::生命形式的第一个征兆 - .
The geologic time scale is used to describe events that occurred millions and billions of years ago. The geologic time scale of Earth's past is organized according to events that took place during different periods on the time scale. Geologic time is the same as the age of the Earth: between 4.404 and 4.57 billion years. Look closely for such events as the extinction of dinosaurs and many marine animals.
::地质时间尺度用来描述数以百万计和数十亿年前发生的事件。地球历史的地质时间尺度是根据时间尺度不同时期发生的事件排列的。地理时间与地球的年代相同:在4.404至4.57亿年之间。仔细观察恐龙和许多海洋动物的灭绝等事件。Evolution of Major Life Forms
::主要生命形式演变Life on Earth began about 3.5 to 4 billion years ago. The first life forms were single-celled organisms similar to bacteria . These first life forms were, of course, very basic, and this then allowed for the evolution of more complex life forms. The first multicellular organisms did not appear until about 610 million years ago. Many different types of organisms evolved during the next ten million years, in an event called the Cambrian Explosion . This sudden burst of evolution may have been caused by some environmental changes that made the Earth's environment more suitable for a wider variety of life forms.
::地球上的生命在大约35亿到40亿年前就开始了。 最初的生命形式是类似于细菌的单细胞生物。 当然,这些最初的生命形式是非常基本的,然后允许更复杂的生命形式进化。 第一批多细胞生物直到大约6亿年前才出现。 许多不同类型的生物在接下来的1 000万年中,在一次名为Cambrian 爆炸的事件中演变。 这种突起的进化可能是一些环境变化造成的,这些环境变化使得地球环境更适合更广泛的生命形式。Plants and fungi did not appear until roughly 500 million years ago. They were soon followed by (insects and spiders). Next came the about 300 million years ago, followed by mammals around 200 million years ago and around 150 million years ago.
::植物和真菌直到大约5亿年前才出现,随后不久就出现了(昆虫和蜘蛛 ) 。 其次是大约3亿年前,其次是大约2亿年前和大约1.5亿年前的哺乳动物。Even though large life forms have been very successful on Earth, most of the life forms on Earth today are still prokaryotes—small, relatively simple single-celled organisms. As it is difficult to identify, observe and study such small forms of life, most of these organisms remain unknown to scientists. Advancing technologies, however, do allow for the identification and study of such organisms.
::尽管地球上的大型生命形式非常成功,但今天地球上的大多数生命形式仍然是小的、相对简单的单细胞生物,由于难以识别、观察和研究这种小生命形式,这些生物大多数对科学家来说仍然不为人所知,但是,先进的技术确实能够识别和研究这种生物。Fossils indicate that many organisms that lived long ago are extinct. Extinction of species is common; in fact, it is estimated that 99% of the species that have ever lived on Earth no longer exist.
::各种物种的灭绝是常见的;事实上,据估计,地球上99%的物种已经不复存在。The basic timeline of a 4.6 billion-year-old Earth includes the following:
::一个46亿年之久的地球的基本时间表包括如下:-
About 3.5 - 3.8 billion years of simple
cells
(prokaryotes).
::大约35-38亿年的简单细胞(prokaryotes)。 -
3 billion years of
.
::30亿年的岁月 -
2 billion years of complex cells (eukaryotes).
::20亿年的复杂细胞(eukaryotes)。 -
1 billion years of multicellular life.
::10亿年的多细胞生命 -
600 million years of simple animals.
::6亿年的简单动物 -
570 million years of arthropods (
ancestors
of insects,
and crustaceans).
::5.7亿年的节肢动物(昆虫和甲壳类动物的祖先)。 -
550 million years of complex animals.
::5亿5千万年的复杂动物 -
500 million years of
and proto-amphibians.
::5亿年的两栖动物和原生两栖动物 -
475 million years of land plants.
::4亿7千5百万年的陆地植物 -
400 million years of insects and
seeds
.
::4亿年的昆虫和种子 -
360 million years of amphibians.
::3亿6千万年的两栖动物 -
300 million years of
.
::3亿年的岁月 -
200 million years of mammals.
::两亿年的哺乳动物 -
150 million years of birds.
::一亿五千万年的鸟类 -
130 million years of flowers.
::1.3亿年的花朵 -
65 million years since the non-avian
dinosaurs
died out.
::自非禽类恐龙死后6500万年 -
2.5 million years since the appearance of
Homo
.
::自同性恋出现以来 已有250万年了 -
200,000 years since the appearance of modern humans.
::自现代人类出现以来 20万年了 -
25,000 years since
Neanderthals
died out.
::尼安德特人死后25000年
Summary
::摘要-
The age of Earth is between 4.4 and 4.57 billion years.
::地球的年龄在44至45.7亿之间。 -
Life on Earth began about 3.5 to 4 billion years ago, and the first life forms were single-celled organisms similar to bacteria.
::地球上的生命大约在35亿到40亿年前就开始了, 第一种生命形式是类似于细菌的单细胞生物。
Explore More
::探索更多Use the resource below to answer the questions that follow.
::利用以下资源回答以下问题。-
Anomalocaris
- Shape of Life
::Anomolocaris - 生命的形状
-
Most fossils found are not of complete organisms. How have scientists responded to this situation? What challenges has this presented?
::大多数发现的化石不是完整的生物体,科学家如何应对这种情况?这带来了什么挑战? -
What were some of the theories as to what type of animal
Anomalocaris
was? What happened to cause these theories to be abandoned?
::什么样的动物是Anomolocaris? 是什么导致这些理论被抛弃的呢? -
How is
Anomalocaris
an example of the scientific process?
::Anomolocaris如何成为科学过程的范例?
Review
::回顾-
What is a significant piece of evidence that was used in the 1800s to suggest Earth is very old?
::1800年代用来表明地球很古老的重要证据是什么? -
Relative to the length of time life has been on Earth, have modern humans appeared recently or in the distant past?
::相对于地球上的寿命,现代人类是最近出现还是远古出现? -
What types of geological events help define geological time scales?
::哪些类型的地质事件有助于界定地质时间尺度? -
When did life on Earth begin? What was the first form of life?
::地球上的生命是什么时候开始的? -
What was the Cambrian Explosion?
::什么是坎布里安爆炸?
-
of ancient sea life on dry land far from oceans. This supported the idea that the Earth changed over time and that some dry land today was once covered by oceans.
