高三英语教案 Unit 4 Green World (背景知识)

减小字体 增大字体 作者:本站收集整理  来源:本站收集整理  发布时间:2009-08-24 08:18:58

I. Background Information
Charles Robert Darwin(1809 –1882)was born on February 26, 1809 in Shrewsbury, England. He was the fifth child and second son of Robert Waring Darwin and Susannah Wedgwood. Darwin was the British naturalist who became famous for his theories of evolution and natural selection. Like several scientists before him, Darwin believed all the life on earth evolved over millions of years from a few common ancestors.
From 1831 to 1836 Darwin served as naturalist aboard the Beagle on a British science expedition around the world. In South America Darwin found fossils of extinct animals that were similar to modern species. On the Galapagos Islands in the Pacific Ocean he noticed many variations among plants and animals of the same general type as those in South America. The expedition visited places around the world, and Darwin studied plants and animals everywhere he went, collecting specimens for further study.
Upon his return to London Darwin conducted through research of his notes and specimens. Out of this study grew several related theories: one, evolution did occur; two, evolutionary change was gradual, requiring thousands to millions of years; three, the primary mechanism for evolution was a process called natural selection; and four, the millions of species alive today arose from a single original life form through a branching process called "specialization."
Darwin's theory of evolutionary selection holds that variation within species occurs randomly and that the survival or extinction of each organism is determined by that organism's ability to adapt to its environment. He set these theories forth in his book called, "On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life" (1859) or "The Origin of Species" for short. After the publication of Origin of Species, Darwin continued to write on botany, geology, and zoology until his death in 1882. He is buried in Westminster Abbey.

Gregor Mendel was born in Heinzendorf, Austria on July 22, 1822. He died in Brno, Austria January 6, 1884. Mendel's first presentation was on his eight years of experimentation with artificial plant hybridization. During his studies he became a member of the Zoologist-botanisher Vernin in Vienna. His first two communications were published in 1853 to 1854. Both articles contained information about damage to plants by insects. Between 1856 to 1863 Mendel cultivated and tested almost 28,000 plants. His explanation was that hybrid germinal and pollen cells that are in their composition correspond in equal number to all constant forms resulting from the combinations of traits united through fertilization. Mendel's rediscovery of his works brought a close to an era of speculation on heredity. Therefore Mendel opened a new pathway of study on heredity to reveal a new mechanism operating in the sense of evolution.

Turesson, Göte Wilhelm (Sweden 1892-1970) Turesson's fame rests on an impressive set of "common environment" experimental growth studies conducted over the period 1919-1927. At that time he became "a pioneer in the use of experimental methods to detect genetic differences between races of plant species that adapt them to different habitats.

Carl Linnaeus (1707-1778), is often called the Father of Taxonomy. His system for naming, ranking, and classifying organisms is still in wide use today (with many changes). His ideas on classification have influenced generations of biologists during and after his own lifetime, even those opposed to the philosophical and theological roots of his work.
He was born on May 23, 1707, in southern Sweden. Carl showed a deep love of plants and a fascination with their names from a very early age. Carl disappointed his parents by showing neither aptitude nor desire for the priesthood, but his family was somewhat consoled when Linnaeus entered the University of Lund in 1727 to study medicine. A year later, he transferred to the University of Uppsala, the most prestigious university in Sweden. Most of Linaeus's time at Uppsala was spent collecting and studying plants, his true love. At the time, training in botany was part of the medical curriculum, for every doctor had to prepare and prescribe drugs derived from medicinal plants. Despite being in hard financial straits, Linnaeus mounted a botanical and ethnographical expedition to Lapland in 1731. In 1734 he mounted another expedition to central Sweden.
Linnaeus went to the Netherlands in 1735, promptly finished his medical degree at the University of Harderwijk, and then enrolled in the University of Leiden for further studies. That same year, he published the first edition of his classification of living things, the Systema Naturae. Returning to Sweden in 1738, he practiced medicine and lectured in Stockholm At Uppsala, he restored the University's botanical garden made three more expeditions to various parts of Sweden, and inspired a generation of students. Nineteen of his students went out on these voyages of discovery to all parts of the world. Perhaps his most famous student, Daniel Solander, was the naturalist on Captain James Cook's first round-the-world voyage, and brought back the first plant collections from Australia and the South Pacific to Europe.
Before Linnaeus, species naming practices varied. Many biologists gave the species they described long, unwieldy Latin names, which could be altered at will; a scientist comparing two descriptions of species might not be able to tell which organisms were being referred to. The need for a workable naming system was made even greater by the huge number of plants and animals that were being brought back to Europe from Asia, Africa, and the Americas. After experimenting with various alternatives, Linnaeus simplified naming immensely by designating one Latin name to indicate the genus, and one as a "shorthand" name for the species. The two names make up the binomial ("two names") species name. For instance, in his two-volume work Species Plantarum (The Species of Plants), Linnaeus renamed the briar rose Rosa canina. This binomial system rapidly became the standard system for naming species. Although Linnaeus was not the first to use binomials, he was the first to use them consistently, and for this reason, Latin names that naturalists used before Linnaeus are not usually considered valid under the rules of nomenclature.

[1] [2]  下一页

Tags:

作者:本站收集整理
  • 好的评价 如果您觉得此文章好,就请您
      0%(0)
  • 差的评价 如果您觉得此文章差,就请您
      0%(0)

文章评论评论内容只代表网友观点,与本站立场无关!

   评论摘要(共 0 条,得分 0 分,平均 0 分) 查看完整评论