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Period: 322 to
Aristotle
He thought some of the simpler invertebrates could arise by spontaneous generation. -
Aug 15, 615
Anaximander
First western thinker to suggest that life arose spontaneously. -
Period: to
Francesco Redi
Italian physician who challenged the spontaneous generation. Carried out a series of experiments on decaying meat in three containers. From this, found out that the generation of maggots by decaying meat resulted from the prescence of fly eggs, and meat did not spontaneousy generate maggots as previously believed. -
Period: to
Lazzaro Spallanzani
He improved on Needham’s experimental design by first sealing glass flasks that contained water and seeds. If the sealed flasks were placed in boiling water for 3/4 of an hour, no growth took place as long as the flasks remained sealed. He proposed that air carried germs to the culture medium, but also commented that the external air might be required for growth of animals already in the medium. -
John Needham
An English priest reported the results of his experiments on spontaneous generation. He boiled mutton broth and tightly stoppered the flasks. Eventually many of the flasks became cloudy and contained microorganisms. He thought organic matter contained a vital force that could confer the properties of life on nonliving matter. -
Period: to
Louis Pasteur
Pasteur had not only resolved the controversy by 1861 but also had shown how to keep solutions. -
John Tyndall
He made the final blow of spontaneous generation, He demonstrated that dust did carry germs and that if dust was absent, broth remained sterile even if directly exposed to air. -
Empedocles
He was a Greek philospher. He accepted the spontaneous generation of life, but held that there had to be trials of combinations of parts of animals that spontaneously arose.