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Piatok, 19. apríla 2024
History of biology in 19th and 20th century
Dátum pridania: 04.04.2008 Oznámkuj: 12345
Autor referátu: rison
Jazyk: Angličtina Počet slov: 1 682
Referát vhodný pre: Gymnázium Počet A4: 5.9
Priemerná známka: 3.00 Rýchle čítanie: 9m 50s
Pomalé čítanie: 14m 45s
History of biology in 19 and 20 century

Biology is a science which studies living organisms. The history of biology is very long and there are many scientists who study that. First man who used the word “biology” was Jean Babtiste Lamarck (1744 - 1849). The history of biology is the study of the living world from ancient to modern times. The first biologists were in an ancient Greece, for example Plato or Aristotle, they started to study nature and living organisms around them. During the Renaissance and early modern period, biological thought was revolutionized by a renewed interest in discovery of many new organisms. The most important scientists in this movement were Vesalius and Harvey, who used experimentation and careful observation in physiology, and naturalists such as Linnaeus and Buffon who began to classify the differences of life, as well as the development and behavior of organisms. The discovery of microscopes explore previously unknown world of microorganisms, laying the groundwork for cell theory.

The cell theory:

This theory was developed in 1838 by botanist Mattias Schleiden and zoologist Theodor Schwan. This theory says:

1. All known living organisms are made from cells.
2. The cell is a basic structural and functional unit of all living organisms.
3. All cells come from pre-existing cells by division.
4. Cells contain hereditary information which is passed from cell to cell during cell division.
5. All cells are basically the same in chemical composition.
6. All energy flow (metabolism and biochemistry) of life occur within cells.

In the 19 century biological sciences such as botany and zoology became more professional scientific disciplines. Lavoisier and other physical scientists began to connect the living and nonliving worlds through physics and chemistry. Explorer-naturalists such as Alexander von Humboldt investigated the interaction between organisms and their environment, and the ways this relationship depends on geography, and started to make new sciences like biogeography, ecology and ethology. Cell theory provided a new perspective on the basic forms of life. These developments, as well as the results from embryology and paleontology, were published in Charles Darwin's theory of evolution by natural selection. In the early 20th century, the rediscovery of Mendel's work led to the rapid development of genetics by Thomas Hunt Morgan and his students. New disciplines developed rapidly, especially after Watson and Crick who propose the double helical structure of DNA .

The most important and famous scientists in 19 and 20 century:

Jean Baptiste Lamarck- In either 1802 or 1809, published his theory of evolution. A number of another attempts were made to support or disprove this theory without the benefit of our modern knowledge of genetics. One experiment involved amputation of mouse tails for successive generations, showing that even after twenty generations, there was no effect: baby mice were still born with tails.

Charles Darwin- He was one of the most important scientists in the history. He published his own theory of evolution. In this theory he publish his opinion what was: the every organism, animal or human, evolve from a few common ancestors through the process of natural selection and every organism has to change or adapt to the nature around them. He first thought about this theory in 1838. Historians think that he didn’t publish his theory because he was afraid that people wouldn’t accept his theory because it was in the difference with the religion. So he didn’t publish it until 1859, when he heard that another scientist, Alfred Wallace had the same ideas. Wallace was close to publishing his ideas. So Darwin published his theory in the book. The name of the book was: On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. This is also just called The Origin of Species.

Theodor Schwan- He was zoologist. Among his many contributions to biology there was the development of cell theory, the discovery of Schwann cells in the peripheral nervous system, the discovery and study of pepsin, the discovery of the organic nature of yeast and the invention of the term metabolism.

Mattias Schleiden- He was a German botanist and co-founder of the cell theory. Schleiden preferred to study plant structure under the microscope. While a professor of botany at the University of Jena, he wrote Contributions to Phytogenesis (1838), in which he stated that the different parts of the plant organism are composed of cells.

Alfred Russel Wallace- He was another naturalist. He was independently working on the theory what was same like Darwin’s. The result of his work was: Darwin was the first person to come up with these ideas, while until recently, Wallace’s work was almost totally ignored. Darwin’s friends want from him to publish his theory, and the Origin of Species was the result. Darwin eventually published several other books describing his ideas and theories. And the Wallace’s work has been forgotten and ignored.
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