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Period: 350 to
Cell Theory
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400
Aristotle
Approximately 384 B.C.-
Was known for his experimental approach and numerous dissections. He was drawn to animal classification in order to discover aspects of connection between the soul and the human body. Some of his animal classifications still stand today. *citation -
400
Medieval Europeans
During the European Renaissance and early modern period, biological thought was revolutionalized in Europe by renewed interest in empiricism and discovery of many novel organisms.
Empiricism- that knowledge arises from evidence gathered via sensory perception, in the formation of ideas, over the notion of innate ideas or tradition in contrast to, for example, rationalism which relies upon reason and can incorporate innate knowledge. -
400
Ancient Egyptians
Approximately 1500 B.C.-
Perhaps the greatest contribution made to science by the Egyptians lay in the field of biology. The priests who prepared corpses for burial learned a great deal about human anatomy as they removed the vital organs. Yet, their religious beliefs prevented them from dissecting a body anymore than was necessary for mummification; to do otherwise was considered sinful. This superstition severely limited their ability to understand the functioning of the human body. -
Sep 9, 1540
Andreas Vesalius
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Hans and Zacharias Janssen
Jansen is accredible for several advancements toward the invention of the telescope and by some historians, he is believed to be the original inventer: his microscope was finished around 1610. He is also accredited as the inventor of the first true compound microscope. This microscope could magnify 9 fold. However, the origin of the microscope is debatable. There is some evidence that his father Hans Janssen assisted him with his inventions but no proof. What exactly Zacharias did is even contro -
Robert Hooke
In 1665 Hooke published Micrographia, a book describing his microscopic and telescopic observations, and some original work in biology. Hooke coined the term cell for describing biological organisms, the term being suggested by the resemblance of plant cells to monks' cells. -
Francesco Redi
did an experiment to determine if rotting meat turned into flies. He found that meat cannot turn into flies and only flies could make more flies. This was an important experiment because it helped to disprove the theory of spontaneous generation. It did this by showing that the rotten meat did not turn into flies and only flies could make more flies. *citation -
Anton van Leeuwenhoek
Dutch microscopist who was the first to observe bacteria and protozoa. As a hobby, Leeuwenhoek began grinding lenses and using them to study minute objects, particularly small organisms. His researches on lower animals refuted the doctrine of spontaneous generation, and his observations helped lay the foundations for the sciences of bacteriology and protozoology. *citation -
John Needham
Needham came up with an experiment that supported his theory of spontaneous generation which is the idea that life occurs spontaneously at the microscopic level without the need for reproduction from preexisting life. His theory was disproved by Lazzaro Spallanzani. -
Lazzaro Spallanzani
Spallanzani suggested that microbes could move through the air to cause what other some scientists of the time called spontaneous generation. He also showed that by boiling the microbes in a sample no spontaneous generation would occur suggesting that contamination was the cause of seemingly spontaneous life. His work suggested that all cells come from preexisting cells. This paved the scientific path for Louis Pasteur's work. -
Jean Baptiste Lamarck
Lamarck is accredited for contributing to the theory of evolution. His primary conribution was the theory of inheritance of accuired characteristics which is sometimes reffered to as Lamarckism. He came up with much evidence that evolution occured due to natural laws which brought him to create the first truly coherent theory of evolution. -
Lorenz Oken
Lorenz Oken came up with a new system of animal classification that demonstrated the path of evolution including:
Dermatozoa- invertabrates
Glossozoa- fish with the first toungues
Rhinozoa- reptiles inwhich the nose opens into the mouth and us used for respiration
Otozoa- birds with the first externally open ears
Ophthalmozoa- mammals including all sensory organs -
Robert Brown
The first to recognize the nucleus (a term that he introduced) as an essential constituent of living cells (1831). Brown recognized the general occurrence of the nucleus in these cells and apparently thought of the organization of the plant in terms of cellular constituents. *citation -
Theodor Schwann
Contributed 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. He also stated that "All living things are composed of cells and cell products." And he proved the cellular origin and development of the most highly differentiated tissues including nails, feathers, and tooth enamel. -
Matthias Schleiden
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. Thus, Schleiden and Theodor Schwann became the first to formulate what was then an informal belief as a principle of biology equal in importance to the atomic theory of chemistry. He also recognized the importance of the cell nucleus. -
Rudolph Virchow
Most widely known scientific contribution is his cell theory, which built on the work of Theodor Schwann. He is cited as the first to recognize leukemia cells. He was one of the first to accept and plagiarize the work of Robert Remak who showed that the origins of cells was the division of preexisting cells. -
Louis Pasteur
Pasteur came up with a process to prevent milk and wine from making people sick (Pasteurization) which was based off his work in germ theory. He had proven spontaneous generation false and replaced it biogenesis which states that all living things came from preexisting life. Biogenesis is the basis or Germ Theory which, though not originally his idea, led Pasteur to discover vaccines for Rabies and Anthrax as well as other medical accomplishments. -
Period: to
Cell Theory
