1.8 生命的演变
章节大纲
-
What you will learn
::你会学到什么-
Timeline of the
on Earth
::地球时间表 -
Darwin’s
theory of evolution by natural selection
::达尔文自然选择的进化理论 -
Evidence
to support the
theory
of evolution
::支持进化理论的证据 -
Misconceptions about evolution
::对进化的误解
Are dinosaurs evidence of past life forms?
::恐龙是过去生命形式的证据吗?Evolution can be described as a change in over time . Dinosaur are significant evidence of evolution and of past life on Earth.
::进化可以说是随时间推移而变化,恐龙是进化的重要证据,也是地球上过去生命的重要证据。Evolution of Life
::生命的演变The diversity of life on Earth today is the result of evolution. Life began on Earth at least 3.5 to 4 billion years ago, and it has been evolving ever since. At first, all living things on Earth were simple, single-celled organisms . Much later, the first evolved, and after that, Earth’s greatly increased. Figure shows a timeline of the history of life on Earth. In the entire span of time, humans are relatively a new addition.
::今天,地球上生命的多样性是进化的结果。 生命至少35亿到40亿年前开始于地球,并且从那时以来一直在演变。 首先,地球上所有生物都是简单的单细胞生物。 远在后期,最初的进化和此后的地球大幅上升。 图显示了地球上生命史的时间表。 在整个时间段,人类相对而言是一个新的添加物。Today, the most accepted theory of life on Earth is evolution, and there is a vast amount of evidence supporting this theory. However, this wasn’t always the case.
::如今,地球上最公认的生命理论是进化,而且有大量证据支持这一理论。 然而,情况并非总是如此。Darwin and the Theory of Evolution
::达尔文和进化理论The idea of evolution has been around for centuries. In fact, it goes all the way back to the ancient Greek philosopher Aristotle. However, evolution is most often associated with Charles Darwin . Darwin published a book on evolution in 1859 titled On the . In the book, Darwin stated the theory of evolution by natural selection. He also presented a great deal of evidence that evolution occurs.
::进化的概念已经存在了几个世纪。事实上,它完全可以追溯到古希腊哲学家亚里士多德。然而,进化往往与查尔斯·达尔文有关。达尔文于1859年出版了一本关于进化的书,书名为《进化论 》 。达尔文在书中指出了自然选择的进化理论。他还提出了大量进化的证据。Evolution is a change in the characteristics of living things over time. As described by Darwin, evolution occurs by a process called . In natural selection, some members of a species, being better adapted or suited to their environment, produce more offspring than others, so they pass "advantageous traits" to their offspring. Over many generations, this can lead to major changes in the characteristics of the species. Evolution explains how living things are changing today and how modern living things have descended from ancient life forms that no longer exist on Earth. As living things evolve, they generally become better suited for their environment. This is because they evolve adaptations . An adaptation is a trait that helps an organism survive and reproduce in a given environment.
::正如达尔文所描述的,进化过程是由一个称为“自然选择”的过程发生的。在自然选择中,一个物种的某些成员,更适应或更适合其环境,产生比其他物种更多的后代,因此它们会把“优势特征”传给后代。在许多代人中,这可能导致物种特征的重大变化。进化解释了生命事物今天是如何变化的,现代生命事物是如何从地球上不再存在的古代生命形态中降生的。随着生命事物的演化,它们一般会变得更适合环境。这是因为它们会演化适应。适应是一种有助于生物在特定环境中生存和繁殖的特征。An example of natural selection is shown in the Figure . In this of giraffes, long necks as well as short necks exist. The long neck giraffes appear to have an advantage in this environment. Having longer necks enabled these giraffes to feed off the higher branches. Over time, the giraffes with longer necks survived long enough to reproduce and pass on this trait to their offspring.
::图中显示了自然选择的例子。在长颈鹿中,颈部长,颈部短,颈部短,颈部长,颈部长,在这种环境中似乎有优势。长颈长,颈部长,使这些长颈鹿能够从高处喂食。随着时间的推移,颈部长的长颈鹿活下来足够长,可以繁殖并传给后代。Natural selection of the long-neck trait in giraffes Despite all the evidence Darwin presented, his theory was not well-received at first. Many people found it hard to accept the idea that humans had evolved from an ape-like ancestor , and they saw evolution as a challenge to their religious beliefs. Look at the cartoon in Figure . Drawn in 1871, it depicts Darwin himself as an ape. The cartoon reflects how many people felt about Darwin and his theory during his own time. Darwin had actually expected this type of reaction to his theory and had waited a long time before publishing his book for this reason. It was only when another scientist, named Alfred Russel Wallace , developed essentially the same theory of evolution that Darwin put his book into print.
::尽管达尔文提出了所有证据,但他的理论一开始并未得到很好地接受。许多人发现很难接受人类从猿类祖先进化而来的思想,他们认为进化是对其宗教信仰的挑战。看图中的漫画。1871年绘制的漫画将达尔文本身描绘成猿人。卡通反映了许多人对达尔文及其理论在自己时代的感受。达尔文实际上期望人们对他的理论作出这种反应,并等待了很长时间才出版他的书。只有另一个科学家,名叫阿尔弗雷德·鲁塞尔·华莱士(Alfred Russel Wallace)的进化理论基本上与达尔文将他的书印刷成印刷品时的进化理论相同。Charles Darwin’s name is linked with the theory of evolution. This cartoon from the 1870s makes fun of both Darwin and his theory. Although Darwin presented a great deal of evidence for evolution in his book, he was unable to explain how evolution occurs. That’s because he knew nothing about genes . As a result, he didn’t know how characteristics are passed from parents to offspring, let alone how they could change over time.
::尽管达尔文在他的书中为进化提供了大量证据,但他无法解释进化是如何发生的。 这是因为他对基因一无所知。 结果,他不知道特性是如何从父母传到后代的,更不用说他们如何随时间变化了。Evolutionary Theory After Darwin
::达尔文之后的进化理论Since Darwin’s time, scientists have gathered even more evidence to support the theory of evolution. Some of the evidence comes from fossils, and some comes from studies that show how similar living things are to one another. By the 1930s, scientists had also learned about genes. As a result, they could finally explain how characteristics of organisms could pass from one generation to the next and change over time.
::自达尔文时代以来,科学家们收集了更多的证据来支持进化理论。 有些证据来自化石,有些则来自表明彼此生活相近的研究。 到了1930年代,科学家们也学到了基因。 结果,他们终于可以解释生物的特征如何从一代传到下一代并随时间变化。Using modern technology, scientists can now directly compare the genes of living species. The more genes different species share in common, the more closely related the species are presumed to be. Consider humans and chimpanzees. They share about 98% of their genes. This means that they shared a common ancestor in the not-too-distant past. This is just one of many pieces of evidence that show we are part of the evolution of life on Earth.
::使用现代技术,科学家现在可以直接比较生物物种的基因。 不同物种的基因共享程度越高,物种被推定为关系越密切。 以人类和黑猩猩为例,它们拥有大约98%的基因。 这意味着它们在不远的过去拥有共同的祖先。 这只是许多证据之一,表明我们是地球上生命进化的一部分。Misconceptions About Evolution
::对进化的误解Today, evolution is still questioned by some people. Often, people who disagree with the theory of evolution do not really understand it. For example, some people think that the theory of evolution explains how life on Earth first began. In fact, the theory explains only how life changed after it first appeared. Some people think the theory of evolution means that humans evolved from modern apes. In fact, the theory suggests humans and modern apes have a common ancestor that lived several million years ago. These and other misconceptions about evolution contribute to the controversy that still surrounds this fundamental principle of biology .
::今天,进化仍然受到一些人的质疑。通常,不同意进化理论的人并不真正理解进化理论。例如,有些人认为进化理论解释了地球生命的起源。事实上,进化理论只解释了生命在最初出现后的变化。有些人认为进化理论意味着人类从现代猿类中演变。事实上,理论表明人类和现代猿类有一个共同的祖先,在数百万年前就已存在了。这些和其他关于进化的错误观念促成了这一生物学基本原则的争论。
Summary
::摘要-
Life began on Earth at least 3.5 to 4 billion years ago, and it has been evolving ever since.
::生命至少35亿到40亿年前开始于地球上, 并且从那以后一直在演变。 -
Darwin stated the theory of evolution by natural selection, presenting a great deal of evidence to support his theory.
::达尔文以自然选择的方式阐述了进化理论,提出了大量证据支持他的理论。 -
Evolution is a change in the characteristics of living things over time. Evolution occurs by natural selection.
::进化是随着时间推移生活特征的变化。进化是通过自然选择发生的。 -
Characteristics of organisms are passed from one generation to the next through their genes.
::生物的特征通过基因代代相传。
Review
::回顾-
What is evolution?
::什么是进化? -
What is natural selection?
::什么是自然选择? -
Briefly, explain the theory of evolution.
::简单解释一下进化理论
-
Timeline of the
on Earth
