Saturday, October 3, 2009

 Aristotle concluded that living things arise from non-living material - spontaneous generation.
 Alhazen (965 – 1040) or Abu Ali Hasan Ibn al-Haitham, an Iraq physicist. His book Kitab-al-Manadhirn was translated into Latin and greatly influenced western science. He is the first to state that eyes received light being reflected off an object, which had a major impact on the development of the first microscope. As a nice to know, he is the one responsible for geometry!
 Jan Baptist van Helmont (1579 - 1644) - wrote a recipe for making rice: Throw grains and old rags into the corner of a room
 Francesco Redi - (1626 - 1697) In 1660 Challenges spontaneous generation. Raw meat and fly maggot experiment – . Critics say Redi’s source of error was the removal of air, which contains an "active principle"
 Anton van Leeuwenhoek - (1632 - 1723) 1700 used a single lens microscope to describe single celled organisms. He called them “animalcules.” Friend of Robert Hooke.
  • First to describe the cellular nature of living things
  • First to see bacteria and protozoa
 Marcello Malpighi (1628 – 1694) An Italian physiologist who used lenses to study plants and animals. He is considered the father of microscopic anatomy. He was a member of the Royal Society in England. He discovered capillaries and completed Harvey’s theory on blood circulation in his book De Pulmonibus in 1661. He published Anatomia Plantarum, which includes his discovery of the stomata on plant leaves.
 Robert Hooke (1635 to 1703) Published Micrografia in 1665- book of objects he looked at under a compound microscope he designed and built. He coined the word cell describe the features of plant tissue (cork).
 John Needham (1713 to 1781) Experimented to prove spontaneous generation occurred. Heated broth in a glass flask and then corked the glass so no air would get in. Bacteria still grew in flask. Needham’s source of error was that he did not boil the broth long enough.
 Lazzaro Spallanzani (1729 to 1799) Repeated Needham’s experiment, but properly boiled the broth and thus refuted spontaneous generation.
 Jean-Baptiste Lamarck (1744 – 1829) “Lamarckism” is the theory that acquired characteristics can be passed on (inherited).
 Matthias Schleiden and Theodor Schwann (In 1838 to 1839) - two German scientists that viewed many organisms under microscope and concluded that all plants and animals were composed of cells.
 Louis Pasteur (1822 to 1895) In 1861 Disproved spontaneous generation once and for all using curved neck flasks.
 Rudolf Ludwig Karl Virchow (1821 – 1902) Stated that all new cells are formed by the division of previously existing cells. 
Thomas Henry Huxley (1825 to 1895) In 1870 is the first to use the word biogenesis, which states that all living things arise only from other living things.
 August Weismann (1834 to 1914) Stated all cells coming from pre-existing cells (Virchow) trace their ancestry to an ancient cell (application of Evolution to cells). Weismann eliminated the idea of inheritance of acquired characteristics from being accepted. To prove his theory, Weismann cut the tails of mice and bred them over several generations, but all the mice were born with tails. This showed that acquired traits are not passed down to offspring.


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